QGIS API Documentation  2.99.0-Master (37c43df)
Public Types | Public Slots | Signals | Public Member Functions | Static Public Member Functions | Protected Slots | Protected Member Functions | Properties | Friends | List of all members
QgsVectorLayer Class Reference

Represents a vector layer which manages a vector based data sets. More...

#include <qgsvectorlayer.h>

Inheritance diagram for QgsVectorLayer:
Inheritance graph
[legend]

Public Types

enum  EditResult {
  Success = 0, EmptyGeometry = 1, EditFailed = 2, FetchFeatureFailed = 3,
  InvalidLayer = 4
}
 Result of an edit operation. More...
 
enum  SelectBehaviour { SetSelection, AddToSelection, IntersectSelection, RemoveFromSelection }
 Selection behaviour. More...
 
enum  VertexMarkerType { SemiTransparentCircle, Cross, NoMarker }
 Editing vertex markers. More...
 
- Public Types inherited from QgsMapLayer
enum  LayerType { VectorLayer, RasterLayer, PluginLayer }
 Types of layers that can be added to a map. More...
 

Public Slots

void checkJoinLayerRemove (const QString &theLayerId)
 Check if there is a join with a layer that will be removed. More...
 
void deselect (const QgsFeatureId featureId)
 Deselect feature by its ID. More...
 
void deselect (const QgsFeatureIds &featureIds)
 Deselect features by their ID. More...
 
void removeSelection ()
 Clear selection. More...
 
void select (QgsFeatureId featureId)
 Select feature by its ID. More...
 
void select (const QgsFeatureIds &featureIds)
 Select features by their ID. More...
 
bool startEditing ()
 Make layer editable. More...
 
virtual void updateExtents ()
 Update the extents for the layer. More...
 
- Public Slots inherited from QgsMapLayer
void emitStyleChanged ()
 Triggers an emission of the styleChanged() signal. More...
 
virtual void invalidTransformInput ()
 Event handler for when a coordinate transform fails due to bad vertex error. More...
 
void setMaximumScale (double scale)
 Sets the maximum scale denominator at which the layer will be visible. More...
 
void setMinimumScale (double scale)
 Sets the minimum scale denominator at which the layer will be visible. More...
 
void setScaleBasedVisibility (const bool enabled)
 Sets whether scale based visibility is enabled for the layer. More...
 
virtual QDateTime timestamp () const
 Time stamp of data source in the moment when data/metadata were loaded by provider. More...
 
void triggerRepaint ()
 Will advice the map canvas (and any other interested party) that this layer requires to be repainted. More...
 

Signals

void attributeAdded (int idx)
 Will be emitted, when a new attribute has been added to this vector layer. More...
 
void attributeDeleted (int idx)
 Will be emitted, when an attribute has been deleted from this vector layer. More...
 
void attributeValueChanged (QgsFeatureId fid, int idx, const QVariant &value)
 Is emitted whenever an attribute value change is done in the edit buffer. More...
 
void beforeAddingExpressionField (const QString &fieldName)
 Will be emitted, when an expression field is going to be added to this vector layer. More...
 
void beforeCommitChanges ()
 Is emitted, before changes are commited to the data provider. More...
 
void beforeEditingStarted ()
 Is emitted, before editing on this layer is started. More...
 
void beforeModifiedCheck () const
 Is emitted, when layer is checked for modifications. Use for last-minute additions. More...
 
void beforeRemovingExpressionField (int idx)
 Will be emitted, when an expression field is going to be deleted from this vector layer. More...
 
void beforeRollBack ()
 Is emitted, before changes are rolled back. More...
 
void committedAttributesAdded (const QString &layerId, const QList< QgsField > &addedAttributes)
 This signal is emitted, when attributes are added to the provider. More...
 
void committedAttributesDeleted (const QString &layerId, const QgsAttributeList &deletedAttributes)
 This signal is emitted, when attributes are deleted from the provider. More...
 
void committedAttributeValuesChanges (const QString &layerId, const QgsChangedAttributesMap &changedAttributesValues)
 This signal is emitted, when attribute value changes are saved to the provider. More...
 
void committedFeaturesAdded (const QString &layerId, const QgsFeatureList &addedFeatures)
 This signal is emitted, when features are added to the provider. More...
 
void committedFeaturesRemoved (const QString &layerId, const QgsFeatureIds &deletedFeatureIds)
 This signal is emitted, when features are deleted from the provider. More...
 
void committedGeometriesChanges (const QString &layerId, const QgsGeometryMap &changedGeometries)
 This signal is emitted, when geometry changes are saved to the provider. More...
 
void displayExpressionChanged ()
 Emitted when the display expression changes. More...
 
void editCommandDestroyed ()
 Signal emitted, whan an edit command is destroyed. More...
 
void editCommandEnded ()
 Signal emitted, when an edit command successfully ended. More...
 
void editCommandStarted (const QString &text)
 Signal emitted when a new edit command has been started. More...
 
void editFormConfigChanged ()
 Will be emitted whenever the edit form configuration of this layer changes. More...
 
void editingStarted ()
 Is emitted, when editing on this layer has started. More...
 
void editingStopped ()
 Is emitted, when edited changes successfully have been written to the data provider. More...
 
void featureAdded (QgsFeatureId fid)
 Emitted when a new feature has been added to the layer. More...
 
void featureBlendModeChanged (QPainter::CompositionMode blendMode)
 Signal emitted when setFeatureBlendMode() is called. More...
 
void featureDeleted (QgsFeatureId fid)
 Emitted when a feature has been deleted. More...
 
void featuresDeleted (const QgsFeatureIds &fids)
 Emitted when features have been deleted. More...
 
void geometryChanged (QgsFeatureId fid, const QgsGeometry &geometry)
 Is emitted whenever a geometry change is done in the edit buffer. More...
 
void labelingFontNotFound (QgsVectorLayer *layer, const QString &fontfamily)
 Emitted when the font family defined for labeling layer is not found on system. More...
 
void layerModified ()
 This signal is emitted when modifications has been done on layer. More...
 
void layerTransparencyChanged (int layerTransparency)
 Signal emitted when setLayerTransparency() is called. More...
 
void mapTipTemplateChanged ()
 Emitted when the map tip changes. More...
 
void raiseError (const QString &msg)
 Signals an error related to this vector layer. More...
 
void readCustomSymbology (const QDomElement &element, QString &errorMessage)
 Signal emitted whenever the symbology (QML-file) for this layer is being read. More...
 
void readOnlyChanged ()
 Emitted when the read only state of this layer is changed. More...
 
void selectionChanged (const QgsFeatureIds &selected, const QgsFeatureIds &deselected, const bool clearAndSelect)
 This signal is emitted when selection was changed. More...
 
void updatedFields ()
 Is emitted, whenever the fields available from this layer have been changed. More...
 
void writeCustomSymbology (QDomElement &element, QDomDocument &doc, QString &errorMessage) const
 Signal emitted whenever the symbology (QML-file) for this layer is being written. More...
 
- Signals inherited from QgsMapLayer
void blendModeChanged (QPainter::CompositionMode blendMode)
 Signal emitted when the blend mode is changed, through QgsMapLayer::setBlendMode() More...
 
void configChanged ()
 Emitted whenever the configuration is changed. More...
 
void crsChanged ()
 Emit a signal that layer's CRS has been reset. More...
 
void dataChanged ()
 Data of layer changed. More...
 
void dependenciesChanged ()
 Emitted when dependencies are changed. More...
 
void legendChanged ()
 Signal emitted when legend of the layer has changed. More...
 
void nameChanged ()
 Emitted when the name has been changed. More...
 
void recalculateExtents () const
 This is used to send a request that any mapcanvas using this layer update its extents. More...
 
void rendererChanged ()
 Signal emitted when renderer is changed. More...
 
void repaintRequested ()
 By emitting this signal the layer tells that either appearance or content have been changed and any view showing the rendered layer should refresh itself. More...
 
void statusChanged (const QString &status)
 Emit a signal with status (e.g. to be caught by QgisApp and display a msg on status bar) More...
 
void styleChanged ()
 Signal emitted whenever a change affects the layer's style. More...
 

Public Member Functions

 QgsVectorLayer (const QString &path=QString::null, const QString &baseName=QString::null, const QString &providerLib=QString::null, bool loadDefaultStyleFlag=true)
 Constructor - creates a vector layer. More...
 
virtual ~QgsVectorLayer ()
 Destructor. More...
 
QgsActionManageractions ()
 Get all layer actions defined on this layer. More...
 
bool addAttribute (const QgsField &field)
 Add an attribute field (but does not commit it) returns true if the field was added. More...
 
int addExpressionField (const QString &exp, const QgsField &fld)
 Add a new field which is calculated by the expression specified. More...
 
bool addFeature (QgsFeature &feature, bool alsoUpdateExtent=true)
 Adds a feature. More...
 
bool addFeatures (QgsFeatureList features, bool makeSelected=true)
 Insert a copy of the given features into the layer (but does not commit it) More...
 
bool addJoin (const QgsVectorJoinInfo &joinInfo)
 Joins another vector layer to this layer. More...
 
int addPart (const QList< QgsPoint > &ring)
 Adds a new part polygon to a multipart feature. More...
 
int addPart (const QgsPointSequence &ring)
 Adds a new part polygon to a multipart feature. More...
 
int addPart (QgsCurve *ring)
 
int addRing (const QList< QgsPoint > &ring, QgsFeatureId *featureId=nullptr)
 Adds a ring to polygon/multipolygon features. More...
 
int addRing (QgsCurve *ring, QgsFeatureId *featureId=nullptr)
 Adds a ring to polygon/multipolygon features (takes ownership) More...
 
int addTopologicalPoints (const QgsGeometry &geom)
 Adds topological points for every vertex of the geometry. More...
 
int addTopologicalPoints (const QgsPoint &p)
 Adds a vertex to segments which intersect point p but don't already have a vertex there. More...
 
QVariant aggregate (QgsAggregateCalculator::Aggregate aggregate, const QString &fieldOrExpression, const QgsAggregateCalculator::AggregateParameters &parameters=QgsAggregateCalculator::AggregateParameters(), QgsExpressionContext *context=nullptr, bool *ok=nullptr) const
 Calculates an aggregated value from the layer's features. More...
 
QgsFeatureIds allFeatureIds () const
 Get all feature Ids. More...
 
QString annotationForm () const
 Get annotation form. More...
 
QString attributeAlias (int index) const
 Returns the alias of an attribute name or a null string if there is no alias. More...
 
QgsStringMap attributeAliases () const
 Returns a map of field name to attribute alias. More...
 
QString attributeDisplayName (int index) const
 Convenience function that returns the attribute alias if defined or the field name else. More...
 
QgsAttributeList attributeList () const
 Returns list of attribute indexes. More...
 
QgsAttributeTableConfig attributeTableConfig () const
 Get the attribute table configuration object. More...
 
void beginEditCommand (const QString &text)
 Create edit command for undo/redo operations. More...
 
QgsRectangle boundingBoxOfSelected () const
 Returns the bounding box of the selected features. If there is no selection, QgsRectangle(0,0,0,0) is returned. More...
 
QgsGeometryCachecache ()
 
QString capabilitiesString () const
 Capabilities for this layer in a friendly format. More...
 
bool changeAttributeValue (QgsFeatureId fid, int field, const QVariant &newValue, const QVariant &oldValue=QVariant())
 Changes an attribute value (but does not commit it) More...
 
bool changeGeometry (QgsFeatureId fid, const QgsGeometry &geom)
 Change feature's geometry. More...
 
bool commitChanges ()
 Attempts to commit any changes to disk. More...
 
QStringList commitErrors () const
 Returns a list containing any error messages generated when attempting to commit changes to the layer. More...
 
QgsConditionalLayerStylesconditionalStyles () const
 Return the conditional styles that are set for this layer. More...
 
QString constraintDescription (int index) const
 Returns the descriptive name for the constraint expression for a specified field index. More...
 
QString constraintExpression (int index) const
 Returns the constraint expression for for a specified field index, if set. More...
 
bool countSymbolFeatures (bool showProgress=true)
 Count features for symbols. More...
 
QgsExpressionContext createExpressionContext () const override
 This method needs to be reimplemented in all classes which implement this interface and return an expression context. More...
 
void createJoinCaches () const
 Caches joined attributes if required (and not already done) More...
 
virtual QgsMapLayerRenderercreateMapRenderer (QgsRenderContext &rendererContext) override
 Return new instance of QgsMapLayerRenderer that will be used for rendering of given context. More...
 
QString dataComment () const
 Returns a comment for the data in the layer. More...
 
QgsVectorDataProviderdataProvider ()
 Returns the data provider. More...
 
const QgsVectorDataProviderdataProvider () const
 Returns the data provider in a const-correct manner. More...
 
QVariant defaultValue (int index, const QgsFeature &feature=QgsFeature(), QgsExpressionContext *context=nullptr) const
 Returns the calculated default value for the specified field index. More...
 
QString defaultValueExpression (int index) const
 Returns the expression used when calculating the default value for a field. More...
 
bool deleteAttribute (int attr)
 Delete an attribute field (but does not commit it) More...
 
bool deleteAttributes (QList< int > attrs)
 Deletes a list of attribute fields (but does not commit it) More...
 
bool deleteFeature (QgsFeatureId fid)
 Delete a feature from the layer (but does not commit it) More...
 
bool deleteFeatures (const QgsFeatureIds &fids)
 Deletes a set of features from the layer (but does not commit it) More...
 
bool deleteSelectedFeatures (int *deletedCount=nullptr)
 Deletes the selected features. More...
 
EditResult deleteVertex (QgsFeatureId featureId, int vertex)
 Deletes a vertex from a feature. More...
 
virtual QSet< QgsMapLayerDependencydependencies () const override
 Gets the list of dependencies. More...
 
void destroyEditCommand ()
 Destroy active command and reverts all changes in it. More...
 
const QgsDiagramLayerSettingsdiagramLayerSettings () const
 
const QgsDiagramRendererdiagramRenderer () const
 
bool diagramsEnabled () const
 Returns whether the layer contains diagrams which are enabled and should be drawn. More...
 
QString displayExpression () const
 Get the preview expression, used to create a human readable preview string. More...
 
QString displayField () const
 This is a shorthand for accessing the displayExpression if it is a simple field. More...
 
QgsVectorLayerEditBuffereditBuffer ()
 Buffer with uncommitted editing operations. Only valid after editing has been turned on. More...
 
const QgsVectorLayerEditBuffereditBuffer () const
 Buffer with uncommitted editing operations. Only valid after editing has been turned on. More...
 
QgsEditFormConfig editFormConfig () const
 Get the configuration of the form used to represent this vector layer. More...
 
void endEditCommand ()
 Finish edit command and add it to undo/redo stack. More...
 
const QSet< QString > & excludeAttributesWfs () const
 A set of attributes that are not advertised in WFS requests with QGIS server. More...
 
const QSet< QString > & excludeAttributesWms () const
 A set of attributes that are not advertised in WMS requests with QGIS server. More...
 
QString expressionField (int index) const
 Returns the expression used for a given expression field. More...
 
QgsRectangle extent () const override
 Return the extent of the layer. More...
 
QPainter::CompositionMode featureBlendMode () const
 Returns the current blending mode for features. More...
 
long featureCount (const QString &legendKey) const
 Number of features rendered with specified legend key. More...
 
long featureCount () const
 Returns feature count including changes which have not yet been committed If you need only the count of committed features call this method on this layer's provider. More...
 
QgsFieldConstraints::Constraints fieldConstraints (int fieldIndex) const
 Returns any constraints which are present for a specified field index. More...
 
QgsFields fields () const
 Returns the list of fields of this layer. More...
 
QgsWkbTypes::GeometryType geometryType () const
 Returns point, line or polygon. More...
 
QList< double > getDoubleValues (const QString &fieldOrExpression, bool &ok, bool selectedOnly=false, int *nullCount=nullptr) const
 Fetches all double values from a specified field name or expression. More...
 
QgsFeature getFeature (QgsFeatureId fid)
 Query the layer for the feature with the given id. More...
 
QgsFeatureIterator getFeatures (const QgsFeatureRequest &request=QgsFeatureRequest()) const
 Query the layer for features specified in request. More...
 
QgsFeatureIterator getFeatures (const QString &expression)
 Query the layer for features matching a given expression. More...
 
QgsFeatureIterator getFeatures (const QgsFeatureIds &fids)
 Query the layer for the features with the given ids. More...
 
QgsFeatureIterator getFeatures (const QgsRectangle &rectangle)
 Query the layer for the features which intersect the specified rectangle. More...
 
virtual QString getStyleFromDatabase (const QString &styleId, QString &msgError)
 Will return the named style corresponding to style id provided. More...
 
QList< QVariant > getValues (const QString &fieldOrExpression, bool &ok, bool selectedOnly=false) const
 Fetches all values from a specified field name or expression. More...
 
bool hasGeometryType () const
 Returns true if this is a geometry layer and false in case of NoGeometry (table only) or UnknownGeometry. More...
 
int insertSegmentVerticesForSnap (const QList< QgsSnappingResult > &snapResults)
 Inserts vertices to the snapped segments. More...
 
bool insertVertex (double x, double y, QgsFeatureId atFeatureId, int beforeVertex)
 Insert a new vertex before the given vertex number, in the given ring, item (first number is index 0), and feature Not meaningful for Point geometries. More...
 
void invertSelection ()
 Select not selected features and deselect selected ones. More...
 
void invertSelectionInRectangle (QgsRectangle &rect)
 Invert selection of features found within the search rectangle (in layer's coordinates) More...
 
virtual bool isEditable () const override
 Returns true if the provider is in editing mode. More...
 
virtual bool isModified () const
 Returns true if the provider has been modified since the last commit. More...
 
virtual bool isSpatial () const override
 Returns true if the layer is considered a spatial layer, ie it has some form of geometry associated with it. More...
 
QgsVectorLayerJoinBufferjoinBuffer ()
 Acccessor to the join buffer object. More...
 
const QgsAbstractVectorLayerLabelinglabeling () const
 Access to labeling configuration. More...
 
bool labelsEnabled () const
 Returns whether the layer contains labels which are enabled and should be drawn. More...
 
int layerTransparency () const
 Returns the current transparency for the vector layer. More...
 
virtual int listStylesInDatabase (QStringList &ids, QStringList &names, QStringList &descriptions, QString &msgError)
 Lists all the style in db split into related to the layer and not related to. More...
 
virtual QString loadNamedStyle (const QString &theURI, bool &theResultFlag, bool loadFromLocalDb)
 Load a named style from file/local db/datasource db. More...
 
virtual QString loadNamedStyle (const QString &theURI, bool &theResultFlag) override
 Calls loadNamedStyle( theURI, theResultFlag, false ); Retained for backward compatibility. More...
 
QString mapTipTemplate () const
 The mapTip is a pretty, html representation for feature information. More...
 
QVariant maximumValue (int index) const
 Returns the maximum value for an attribute column or an invalid variant in case of error. More...
 
QString metadata () const override
 Obtain Metadata for this layer. More...
 
QVariant minimumValue (int index) const
 Returns the minimum value for an attribute column or an invalid variant in case of error. More...
 
void modifySelection (const QgsFeatureIds &selectIds, const QgsFeatureIds &deselectIds)
 Modifies the current selection on this layer. More...
 
bool moveVertex (double x, double y, QgsFeatureId atFeatureId, int atVertex)
 Moves the vertex at the given position number, ring and item (first number is index 0), and feature to the given coordinates. More...
 
bool moveVertex (const QgsPointV2 &p, QgsFeatureId atFeatureId, int atVertex)
 Moves the vertex at the given position number, ring and item (first number is index 0), and feature to the given coordinates. More...
 
QgsAttributeList pendingAllAttributesList () const
 Returns list of attribute indexes. More...
 
long pendingFeatureCount () const
 Returns feature count including changes which have not yet been committed Alias for featureCount(). More...
 
QgsFields pendingFields () const
 Returns the list of fields of this layer. More...
 
QgsAttributeList pendingPkAttributesList () const
 Returns list of attributes making up the primary key Alias for pkAttributeList(). More...
 
QgsAttributeList pkAttributeList () const
 Returns list of attributes making up the primary key. More...
 
QString providerType () const
 Return the provider type for this layer. More...
 
bool readSld (const QDomNode &node, QString &errorMessage) override
 
bool readStyle (const QDomNode &node, QString &errorMessage) override
 Read the style for the current layer from the Dom node supplied. More...
 
bool readSymbology (const QDomNode &node, QString &errorMessage) override
 Read the symbology for the current layer from the Dom node supplied. More...
 
virtual bool readXml (const QDomNode &layer_node) override
 Reads vector layer specific state from project file Dom node. More...
 
QList< QgsRelationreferencingRelations (int idx) const
 Get relations, where the foreign key is on this layer. More...
 
virtual void reload () override
 Synchronises with changes in the datasource. More...
 
void removeExpressionField (int index)
 Remove an expression field. More...
 
void removeFieldAlias (int index)
 Removes an alias (a display name) for attributes to display in dialogs. More...
 
void removeFieldConstraint (int index, QgsFieldConstraints::Constraint constraint)
 Removes a constraint for a specified field index. More...
 
bool removeJoin (const QString &joinLayerId)
 Removes a vector layer join. More...
 
bool renameAttribute (int index, const QString &newName)
 Renames an attribute field (but does not commit it). More...
 
QgsFeatureRendererrenderer ()
 Return renderer. More...
 
const QgsFeatureRendererrenderer () const
 Return const renderer. More...
 
bool rollBack (bool deleteBuffer=true)
 Stop editing and discard the edits. More...
 
virtual void saveStyleToDatabase (const QString &name, const QString &description, bool useAsDefault, const QString &uiFileContent, QString &msgError)
 Save named and sld style of the layer to the style table in the db. More...
 
void selectAll ()
 Select all the features. More...
 
void selectByExpression (const QString &expression, SelectBehaviour behaviour=SetSelection)
 Select matching features using an expression. More...
 
void selectByIds (const QgsFeatureIds &ids, SelectBehaviour behaviour=SetSelection)
 Select matching features using a list of feature IDs. More...
 
void selectByRect (QgsRectangle &rect, SelectBehaviour behaviour=SetSelection)
 Select features found within the search rectangle (in layer's coordinates) More...
 
int selectedFeatureCount () const
 The number of features that are selected in this layer. More...
 
QgsFeatureList selectedFeatures () const
 Get a copy of the user-selected features. More...
 
const QgsFeatureIdsselectedFeaturesIds () const
 Return reference to identifiers of selected features. More...
 
QgsFeatureIterator selectedFeaturesIterator (QgsFeatureRequest request=QgsFeatureRequest()) const
 Get an iterator of the selected features. More...
 
void setAnnotationForm (const QString &ui)
 Set annotation form for layer. More...
 
void setAttributeTableConfig (const QgsAttributeTableConfig &attributeTableConfig)
 Set the attribute table configuration object. More...
 
void setConstraintExpression (int index, const QString &expression, const QString &description=QString())
 Set the constraint expression for the specified field index. More...
 
void setCoordinateSystem ()
 Setup the coordinate system transformation for the layer. More...
 
void setDataSource (const QString &dataSource, const QString &baseName, const QString &provider, bool loadDefaultStyleFlag=false)
 Update the data source of the layer. More...
 
void setDefaultValueExpression (int index, const QString &expression)
 Sets an expression to use when calculating the default value for a field. More...
 
virtual bool setDependencies (const QSet< QgsMapLayerDependency > &layers) override
 Sets the list of dependencies. More...
 
void setDiagramLayerSettings (const QgsDiagramLayerSettings &s)
 
void setDiagramRenderer (QgsDiagramRenderer *r)
 Sets diagram rendering object (takes ownership) More...
 
void setDisplayExpression (const QString &displayExpression)
 Set the preview expression, used to create a human readable preview string. More...
 
void setEditFormConfig (const QgsEditFormConfig &editFormConfig)
 Get the configuration of the form used to represent this vector layer. More...
 
void setExcludeAttributesWfs (const QSet< QString > &att)
 A set of attributes that are not advertised in WFS requests with QGIS server. More...
 
void setExcludeAttributesWms (const QSet< QString > &att)
 A set of attributes that are not advertised in WMS requests with QGIS server. More...
 
void setFeatureBlendMode (QPainter::CompositionMode blendMode)
 Set the blending mode used for rendering each feature. More...
 
void setFieldAlias (int index, const QString &aliasString)
 Sets an alias (a display name) for attributes to display in dialogs. More...
 
void setFieldConstraint (int index, QgsFieldConstraints::Constraint constraint, QgsFieldConstraints::ConstraintStrength strength=QgsFieldConstraints::ConstraintStrengthHard)
 Sets a constraint for a specified field index. More...
 
void setLabeling (QgsAbstractVectorLayerLabeling *labeling)
 Set labeling configuration. More...
 
void setLayerTransparency (int layerTransparency)
 Set the transparency for the vector layer. More...
 
void setMapTipTemplate (const QString &mapTipTemplate)
 The mapTip is a pretty, html representation for feature information. More...
 
void setProviderEncoding (const QString &encoding)
 Sets the textencoding of the data provider. More...
 
bool setReadOnly (bool readonly=true)
 Make layer read-only (editing disabled) or not. More...
 
void setRenderer (QgsFeatureRenderer *r)
 Set renderer which will be invoked to represent this layer. More...
 
void setSimplifyMethod (const QgsVectorSimplifyMethod &simplifyMethod)
 Set the simplification settings for fast rendering of features. More...
 
virtual bool setSubsetString (const QString &subset)
 Set the string (typically sql) used to define a subset of the layer. More...
 
bool simplifyDrawingCanbeApplied (const QgsRenderContext &renderContext, QgsVectorSimplifyMethod::SimplifyHint simplifyHint) const
 Returns whether the VectorLayer can apply the specified simplification hint. More...
 
const QgsVectorSimplifyMethodsimplifyMethod () const
 Returns the simplification settings for fast rendering of features. More...
 
bool snapPoint (QgsPoint &point, double tolerance)
 Snaps a point to the closest vertex if there is one within the snapping tolerance. More...
 
int snapWithContext (const QgsPoint &startPoint, double snappingTolerance, QMultiMap< double, QgsSnappingResult > &snappingResults, QgsSnapper::SnappingType snap_to)
 Snaps to segment or vertex within given tolerance. More...
 
int splitFeatures (const QList< QgsPoint > &splitLine, bool topologicalEditing=false)
 Splits features cut by the given line. More...
 
int splitParts (const QList< QgsPoint > &splitLine, bool topologicalEditing=false)
 Splits parts cut by the given line. More...
 
QString storageType () const
 Returns the permanent storage type for this layer as a friendly name. More...
 
virtual QString subsetString () const
 Get the string (typically sql) used to define a subset of the layer. More...
 
int translateFeature (QgsFeatureId featureId, double dx, double dy)
 Translates feature by dx, dy. More...
 
QStringList uniqueStringsMatching (int index, const QString &substring, int limit=-1, QgsFeedback *feedback=nullptr) const
 Returns unique string values of an attribute which contain a specified subset string. More...
 
void uniqueValues (int index, QList< QVariant > &uniqueValues, int limit=-1) const
 Calculates a list of unique values contained within an attribute in the layer. More...
 
void updateExpressionField (int index, const QString &exp)
 Changes the expression used to define an expression based (virtual) field. More...
 
bool updateFeature (QgsFeature &f)
 Updates an existing feature. More...
 
void updateFields ()
 Assembles mUpdatedFields considering provider fields, joined fields and added fields. More...
 
const QList< QgsVectorJoinInfovectorJoins () const
 
QgsWkbTypes::Type wkbType () const
 Returns the WKBType or WKBUnknown in case of error. More...
 
bool writeSld (QDomNode &node, QDomDocument &doc, QString &errorMessage, const QgsStringMap &props=QgsStringMap()) const
 Writes the symbology of the layer into the document provided in SLD 1.1 format. More...
 
bool writeStyle (QDomNode &node, QDomDocument &doc, QString &errorMessage) const override
 Write just the style information for the layer into the document. More...
 
bool writeSymbology (QDomNode &node, QDomDocument &doc, QString &errorMessage) const override
 Write the symbology for the layer into the docment provided. More...
 
virtual bool writeXml (QDomNode &layer_node, QDomDocument &doc) const override
 Write vector layer specific state to project file Dom node. More...
 
- Public Member Functions inherited from QgsMapLayer
 QgsMapLayer (QgsMapLayer::LayerType type=VectorLayer, const QString &name=QString::null, const QString &source=QString::null)
 Constructor for QgsMapLayer. More...
 
virtual ~QgsMapLayer ()
 
QString abstract () const
 Returns the abstract of the layer used by QGIS Server in GetCapabilities request. More...
 
QString attribution () const
 Returns the attribution of the layer used by QGIS Server in GetCapabilities request. More...
 
QString attributionUrl () const
 Returns the attribution URL of the layer used by QGIS Server in GetCapabilities request. More...
 
QPainter::CompositionMode blendMode () const
 Returns the current blending mode for a layer. More...
 
QgsCoordinateReferenceSystem crs () const
 Returns the layer's spatial reference system. More...
 
QVariant customProperty (const QString &value, const QVariant &defaultValue=QVariant()) const
 Read a custom property from layer. More...
 
QString dataUrl () const
 Returns the DataUrl of the layer used by QGIS Server in GetCapabilities request. More...
 
QString dataUrlFormat () const
 Returns the DataUrl format of the layer used by QGIS Server in GetCapabilities request. More...
 
virtual QgsError error () const
 Get current status error. More...
 
virtual void exportNamedStyle (QDomDocument &doc, QString &errorMsg) const
 Export the properties of this layer as named style in a QDomDocument. More...
 
virtual void exportSldStyle (QDomDocument &doc, QString &errorMsg) const
 Export the properties of this layer as SLD style in a QDomDocument. More...
 
bool hasScaleBasedVisibility () const
 Returns whether scale based visibility is enabled for the layer. More...
 
QString id () const
 Returns the layer's unique ID, which is used to access this layer from QgsMapLayerRegistry. More...
 
virtual bool importNamedStyle (QDomDocument &doc, QString &errorMsg)
 Import the properties of this layer from a QDomDocument. More...
 
bool isInScaleRange (double scale) const
 Tests whether the layer should be visible at the specified scale. More...
 
bool isValid () const
 Return the status of the layer. More...
 
QString keywordList () const
 Returns the keyword list of the layer used by QGIS Server in GetCapabilities request. More...
 
QgsMapLayerLegendlegend () const
 Can be null. More...
 
QString legendUrl () const
 
QString legendUrlFormat () const
 
virtual QString loadDefaultStyle (bool &resultFlag)
 Retrieve the default style for this layer if one exists (either as a .qml file on disk or as a record in the users style table in their personal qgis.db) More...
 
virtual bool loadNamedStyleFromDb (const QString &db, const QString &uri, QString &qml)
 Retrieve a named style for this layer from a sqlite database. More...
 
virtual QString loadSldStyle (const QString &uri, bool &resultFlag)
 Attempts to style the layer using the formatting from an SLD type file. More...
 
double maximumScale () const
 Returns the maximum scale denominator at which the layer is visible. More...
 
QString metadataUrl () const
 Returns the metadata URL of the layer used by QGIS Server in GetCapabilities request. More...
 
QString metadataUrlFormat () const
 Returns the metadata format of the layer used by QGIS Server in GetCapabilities request. More...
 
QString metadataUrlType () const
 Returns the metadata type of the layer used by QGIS Server in GetCapabilities request. More...
 
double minimumScale () const
 Returns the minimum scale denominator at which the layer is visible. More...
 
QString name () const
 Returns the display name of the layer. More...
 
QString originalName () const
 Returns the original name of the layer. More...
 
QString publicSource () const
 Gets a version of the internal layer definition that has sensitive bits removed (for example, the password). More...
 
bool readLayerXml (const QDomElement &layerElement)
 Sets state from Dom document. More...
 
bool readOnly () const
 Returns if this layer is read only. More...
 
void removeCustomProperty (const QString &key)
 Remove a custom property from layer. More...
 
virtual QString saveDefaultStyle (bool &resultFlag)
 Save the properties of this layer as the default style (either as a .qml file on disk or as a record in the users style table in their personal qgis.db) More...
 
virtual QString saveNamedStyle (const QString &uri, bool &resultFlag)
 Save the properties of this layer as a named style (either as a .qml file on disk or as a record in the users style table in their personal qgis.db) More...
 
virtual QString saveSldStyle (const QString &uri, bool &resultFlag) const
 Saves the properties of this layer to an SLD format file. More...
 
void setAbstract (const QString &abstract)
 Sets the abstract of the layer used by QGIS Server in GetCapabilities request. More...
 
void setAttribution (const QString &attrib)
 Sets the attribution of the layer used by QGIS Server in GetCapabilities request. More...
 
void setAttributionUrl (const QString &attribUrl)
 Sets the attribution URL of the layer used by QGIS Server in GetCapabilities request. More...
 
void setBlendMode (QPainter::CompositionMode blendMode)
 Set the blending mode used for rendering a layer. More...
 
void setCrs (const QgsCoordinateReferenceSystem &srs, bool emitSignal=true)
 Sets layer's spatial reference system. More...
 
void setCustomProperty (const QString &key, const QVariant &value)
 Set a custom property for layer. More...
 
void setDataUrl (const QString &dataUrl)
 Sets the DataUrl of the layer used by QGIS Server in GetCapabilities request. More...
 
void setDataUrlFormat (const QString &dataUrlFormat)
 Sets the DataUrl format of the layer used by QGIS Server in GetCapabilities request. More...
 
void setKeywordList (const QString &keywords)
 Sets the keyword list of the layer used by QGIS Server in GetCapabilities request. More...
 
virtual void setLayerOrder (const QStringList &layers)
 Reorders the previously selected sublayers of this layer from bottom to top. More...
 
void setLegend (QgsMapLayerLegend *legend)
 Assign a legend controller to the map layer. More...
 
void setLegendUrl (const QString &legendUrl)
 
void setLegendUrlFormat (const QString &legendUrlFormat)
 
void setMetadataUrl (const QString &metaUrl)
 Sets the metadata URL of the layer used by QGIS Server in GetCapabilities request. More...
 
void setMetadataUrlFormat (const QString &metaUrlFormat)
 Sets the metadata format of the layer used by QGIS Server in GetCapabilities request. More...
 
void setMetadataUrlType (const QString &metaUrlType)
 Set the metadata type of the layer used by QGIS Server in GetCapabilities request MetadataUrlType indicates the standard to which the metadata complies. More...
 
void setName (const QString &name)
 Set the display name of the layer. More...
 
void setShortName (const QString &shortName)
 Sets the short name of the layer used by QGIS Server to identify the layer. More...
 
virtual void setSubLayerVisibility (const QString &name, bool visible)
 Set the visibility of the given sublayer name. More...
 
void setTitle (const QString &title)
 Sets the title of the layer used by QGIS Server in GetCapabilities request. More...
 
QString shortName () const
 Returns the short name of the layer used by QGIS Server to identify the layer. More...
 
QString source () const
 Returns the source for the layer. More...
 
QgsMapLayerStyleManagerstyleManager () const
 Get access to the layer's style manager. More...
 
virtual QString styleURI () const
 Retrieve the style URI for this layer (either as a .qml file on disk or as a record in the users style table in their personal qgis.db) More...
 
virtual QStringList subLayers () const
 Returns the sublayers of this layer. More...
 
QString title () const
 Returns the title of the layer used by QGIS Server in GetCapabilities request. More...
 
QgsMapLayer::LayerType type () const
 Returns the type of the layer. More...
 
QUndoStack * undoStack ()
 Return pointer to layer's undo stack. More...
 
QUndoStack * undoStackStyles ()
 Return pointer to layer's style undo stack. More...
 
bool writeLayerXml (QDomElement &layerElement, QDomDocument &document, const QString &relativeBasePath=QString::null) const
 Stores state in Dom node. More...
 
- Public Member Functions inherited from QgsExpressionContextGenerator
virtual ~QgsExpressionContextGenerator ()
 

Static Public Member Functions

static void drawVertexMarker (double x, double y, QPainter &p, QgsVectorLayer::VertexMarkerType type, int vertexSize)
 Draws a vertex symbol at (screen) coordinates x, y. (Useful to assist vertex editing.) More...
 
- Static Public Member Functions inherited from QgsMapLayer
static QDomDocument asLayerDefinition (const QList< QgsMapLayer *> &layers, const QString &relativeBasePath=QString::null)
 Returns the given layer as a layer definition document Layer definitions store the data source as well as styling and custom properties. More...
 
static QString capitaliseLayerName (const QString &name)
 A convenience function to (un)capitalise the layer name. More...
 
static QList< QgsMapLayer * > fromLayerDefinition (QDomDocument &document, bool addToRegistry=false, bool addToLegend=false)
 Creates a new layer from a layer defininition document. More...
 
static QList< QgsMapLayer * > fromLayerDefinitionFile (const QString &qlrfile)
 

Protected Slots

void invalidateSymbolCountedFlag ()
 

Protected Member Functions

void setExtent (const QgsRectangle &rect) override
 Set the extent. More...
 
- Protected Member Functions inherited from QgsMapLayer
void appendError (const QgsErrorMessage &error)
 Add error message. More...
 
bool hasDependencyCycle (const QSet< QgsMapLayerDependency > &layers) const
 Checks whether a new set of dependencies will introduce a cycle. More...
 
void readCustomProperties (const QDomNode &layerNode, const QString &keyStartsWith="")
 Read custom properties from project file. More...
 
void readStyleManager (const QDomNode &layerNode)
 Read style manager's configuration (if any). To be called by subclasses. More...
 
void setError (const QgsError &error)
 Set error message. More...
 
void setValid (bool valid)
 Set whether layer is valid or not - should be used in constructor. More...
 
void writeCustomProperties (QDomNode &layerNode, QDomDocument &doc) const
 Write custom properties to project file. More...
 
void writeStyleManager (QDomNode &layerNode, QDomDocument &doc) const
 Write style manager's configuration (if exists). To be called by subclasses. More...
 

Properties

QString displayExpression
 
QgsEditFormConfig editFormConfig
 
QString mapTipTemplate
 
bool readOnly
 
- Properties inherited from QgsMapLayer
QString name
 Read property of QString layerName. More...
 

Friends

class QgsVectorLayerEditBuffer
 
class QgsVectorLayerFeatureSource
 

Additional Inherited Members

- Protected Attributes inherited from QgsMapLayer
QString mAbstract
 Description of the layer. More...
 
QString mAttribution
 Attribution of the layer. More...
 
QString mAttributionUrl
 
QString mDataSource
 Data source description string, varies by layer type. More...
 
QString mDataUrl
 DataUrl of the layer. More...
 
QString mDataUrlFormat
 
QSet< QgsMapLayerDependencymDependencies
 List of layers that may modify this layer on modification. More...
 
QgsError mError
 Error. More...
 
QgsRectangle mExtent
 Extent of the layer. More...
 
QString mKeywordList
 
QString mLayerName
 Name of the layer - used for display. More...
 
QString mLayerOrigName
 Original name of the layer. More...
 
QString mLegendUrl
 WMS legend. More...
 
QString mLegendUrlFormat
 
QString mMetadataUrl
 MetadataUrl of the layer. More...
 
QString mMetadataUrlFormat
 
QString mMetadataUrlType
 
QString mShortName
 
QString mTitle
 
bool mValid
 Indicates if the layer is valid and can be drawn. More...
 

Detailed Description

Represents a vector layer which manages a vector based data sets.

The QgsVectorLayer is instantiated by specifying the name of a data provider, such as postgres or wfs, and url defining the specific data set to connect to. The vector layer constructor in turn instantiates a QgsVectorDataProvider subclass corresponding to the provider type, and passes it the url. The data provider connects to the data source.

The QgsVectorLayer provides a common interface to the different data types. It also manages editing transactions.

Sample usage of the QgsVectorLayer class:

QString uri = "point?crs=epsg:4326&field=id:integer";
QgsVectorLayer *scratchLayer = new QgsVectorLayer(uri, "Scratch point layer", "memory");

The main data providers supported by QGIS are listed below.

Vector data providers

Memory data providerType (memory)

The memory data provider is used to construct in memory data, for example scratch data or data generated from spatial operations such as contouring. There is no inherent persistent storage of the data. The data source uri is constructed. The url specifies the geometry type ("point", "linestring", "polygon", "multipoint","multilinestring","multipolygon"), optionally followed by url parameters as follows:

An example url is "Point?crs=epsg:4326&field=id:integer&field=name:string(20)&index=yes"

OGR data provider (ogr)

Accesses data using the OGR drivers (http://www.gdal.org/ogr/ogr_formats.html). The url is the OGR connection string. A wide variety of data formats can be accessed using this driver, including file based formats used by many GIS systems, database formats, and web services. Some of these formats are also supported by custom data providers listed below.

Spatialite data provider (spatialite)

Access data in a spatialite database. The url defines the connection parameters, table, geometry column, and other attributes. The url can be constructed using the QgsDataSourceUri class.

Postgresql data provider (postgres)

Connects to a postgresql database. The url defines the connection parameters, table, geometry column, and other attributes. The url can be constructed using the QgsDataSourceUri class.

Microsoft SQL server data provider (mssql)

Connects to a Microsoft SQL server database. The url defines the connection parameters, table, geometry column, and other attributes. The url can be constructed using the QgsDataSourceUri class.

WFS (web feature service) data provider (wfs)

Used to access data provided by a web feature service.

The url can be a HTTP url to a WFS server (legacy, e.g. http://foobar/wfs?TYPENAME=xxx&SRSNAME=yyy[&FILTER=zzz]), or, starting with QGIS 2.16, a URI constructed using the QgsDataSourceUri class with the following parameters :

The ‘FILTER’ query string parameter can be used to filter the WFS feature type. The ‘FILTER’ key value can either be a QGIS expression or an OGC XML filter. If the value is set to a QGIS expression the driver will turn it into OGC XML filter before passing it to the WFS server. Beware the QGIS expression filter only supports” =, !=, <, >, <=, >=, AND, OR, NOT, LIKE, IS NULL” attribute operators, “BBOX, Disjoint, Intersects, Touches, Crosses, Contains, Overlaps, Within” spatial binary operators and the QGIS local “geomFromWKT, geomFromGML” geometry constructor functions.

Also note:

Delimited text file data provider (delimitedtext)

Accesses data in a delimited text file, for example CSV files generated by spreadsheets. The contents of the file are split into columns based on specified delimiter characters. Each record may be represented spatially either by an X and Y coordinate column, or by a WKT (well known text) formatted columns.

The url defines the filename, the formatting options (how the text in the file is divided into data fields, and which fields contain the X,Y coordinates or WKT text definition. The options are specified as url query items.

At its simplest the url can just be the filename, in which case it will be loaded as a CSV formatted file.

The url may include the following items:

-subsetIndex=(yes|no)

Determines whether the provider generates an index to improve the efficiency of subsets. The default is yes

-spatialIndex=(yes|no)

Determines whether the provider generates a spatial index. The default is no.

-watchFile=(yes|no)

Defines whether the file will be monitored for changes. The default is to monitor for changes.

GPX data provider (gpx)

Provider reads tracks, routes, and waypoints from a GPX file. The url defines the name of the file, and the type of data to retrieve from it ("track", "route", or "waypoint").

An example url is "/home/user/data/holiday.gpx?type=route"

Grass data provider (grass)

Provider to display vector data in a GRASS GIS layer.

TODO QGIS3: Remove virtual from non-inherited methods (like isModified)

See also
QgsVectorLayerUtils()

Definition at line 412 of file qgsvectorlayer.h.

Member Enumeration Documentation

§ EditResult

Result of an edit operation.

Enumerator
Success 

Edit operation was successful.

EmptyGeometry 

Edit operation resulted in an empty geometry.

EditFailed 

Edit operation failed.

FetchFeatureFailed 

Unable to fetch requested feature.

InvalidLayer 

Edit failed due to invalid layer.

Definition at line 424 of file qgsvectorlayer.h.

§ SelectBehaviour

Selection behaviour.

Enumerator
SetSelection 

Set selection, removing any existing selection.

AddToSelection 

Add selection to current selection.

IntersectSelection 

Modify current selection to include only select features which match.

RemoveFromSelection 

Remove from current selection.

Definition at line 434 of file qgsvectorlayer.h.

§ VertexMarkerType

Editing vertex markers.

Enumerator
SemiTransparentCircle 
Cross 
NoMarker 

Definition at line 1349 of file qgsvectorlayer.h.

Constructor & Destructor Documentation

§ QgsVectorLayer()

QgsVectorLayer::QgsVectorLayer ( const QString &  path = QString::null,
const QString &  baseName = QString::null,
const QString &  providerLib = QString::null,
bool  loadDefaultStyleFlag = true 
)

Constructor - creates a vector layer.

The QgsVectorLayer is constructed by instantiating a data provider. The provider interprets the supplied path (url) of the data source to connect to and access the data.

Parameters
pathThe path or url of the parameter. Typically this encodes parameters used by the data provider as url query items.
baseNameThe name used to represent the layer in the legend
providerLibThe name of the data provider, eg "memory", "postgres"
loadDefaultStyleFlagwhether to load the default style

Definition at line 123 of file qgsvectorlayer.cpp.

§ ~QgsVectorLayer()

QgsVectorLayer::~QgsVectorLayer ( )
virtual

Destructor.

Definition at line 173 of file qgsvectorlayer.cpp.

Member Function Documentation

§ actions()

QgsActionManager* QgsVectorLayer::actions ( )
inline

Get all layer actions defined on this layer.

The pointer which is returned directly points to the actions object which is used by the layer, so any changes are immediately applied.

Definition at line 593 of file qgsvectorlayer.h.

§ addAttribute()

bool QgsVectorLayer::addAttribute ( const QgsField field)

Add an attribute field (but does not commit it) returns true if the field was added.

Definition at line 2171 of file qgsvectorlayer.cpp.

§ addExpressionField()

int QgsVectorLayer::addExpressionField ( const QString &  exp,
const QgsField fld 
)

Add a new field which is calculated by the expression specified.

Parameters
expThe expression which calculates the field
fldThe field to calculate
Returns
The index of the new field
Note
added in 2.6, return value added in 2.9

Definition at line 2905 of file qgsvectorlayer.cpp.

§ addFeature()

bool QgsVectorLayer::addFeature ( QgsFeature feature,
bool  alsoUpdateExtent = true 
)

Adds a feature.

Parameters
featurefeature to add
alsoUpdateExtentIf True, will also go to the effort of e.g. updating the extents.
Returns
True in case of success and False in case of error

Definition at line 955 of file qgsvectorlayer.cpp.

§ addFeatures()

bool QgsVectorLayer::addFeatures ( QgsFeatureList  features,
bool  makeSelected = true 
)

Insert a copy of the given features into the layer (but does not commit it)

Definition at line 2518 of file qgsvectorlayer.cpp.

§ addJoin()

bool QgsVectorLayer::addJoin ( const QgsVectorJoinInfo joinInfo)

Joins another vector layer to this layer.

Parameters
joinInfojoin object containing join layer id, target and source field
Note
since 2.6 returns bool indicating whether the join can be added

Definition at line 2877 of file qgsvectorlayer.cpp.

§ addPart() [1/3]

int QgsVectorLayer::addPart ( const QList< QgsPoint > &  ring)

Adds a new part polygon to a multipart feature.

Returns
0 in case of success, 1 if selected feature is not multipart, 2 if ring is not a valid geometry, 3 if new polygon ring not disjoint with existing rings, 4 if no feature was selected, 5 if several features are selected, 6 if selected geometry not found 7 layer not editable

Definition at line 1159 of file qgsvectorlayer.cpp.

§ addPart() [2/3]

int QgsVectorLayer::addPart ( const QgsPointSequence ring)

Adds a new part polygon to a multipart feature.

Returns
0 in case of success, 1 if selected feature is not multipart, 2 if ring is not a valid geometry, 3 if new polygon ring not disjoint with existing rings, 4 if no feature was selected, 5 if several features are selected, 6 if selected geometry not found 7 layer not editable
Note
available in python bindings as addPartV2

Definition at line 1185 of file qgsvectorlayer.cpp.

§ addPart() [3/3]

int QgsVectorLayer::addPart ( QgsCurve ring)
Note
available in python as addCurvedPart

Definition at line 1211 of file qgsvectorlayer.cpp.

§ addRing() [1/2]

int QgsVectorLayer::addRing ( const QList< QgsPoint > &  ring,
QgsFeatureId featureId = nullptr 
)

Adds a ring to polygon/multipolygon features.

Parameters
ringring to add
featureIdif specified, feature ID for feature ring was added to will be stored in this parameter
Returns
0 in case of success, 1 problem with feature type, 2 ring not closed, 3 ring not valid, 4 ring crosses existing rings, 5 no feature found where ring can be inserted 6 layer not editable

Definition at line 1098 of file qgsvectorlayer.cpp.

§ addRing() [2/2]

int QgsVectorLayer::addRing ( QgsCurve ring,
QgsFeatureId featureId = nullptr 
)

Adds a ring to polygon/multipolygon features (takes ownership)

Parameters
ringring to add
featureIdif specified, feature ID for feature ring was added to will be stored in this parameter
Returns
0 in case of success 1 problem with feature type 2 ring not closed 6 layer not editable
Note
available in python as addCurvedRing

Definition at line 1121 of file qgsvectorlayer.cpp.

§ addTopologicalPoints() [1/2]

int QgsVectorLayer::addTopologicalPoints ( const QgsGeometry geom)

Adds topological points for every vertex of the geometry.

Parameters
geomthe geometry where each vertex is added to segments of other features
Note
geom is not going to be modified by the function
Returns
0 in case of success

Definition at line 1268 of file qgsvectorlayer.cpp.

§ addTopologicalPoints() [2/2]

int QgsVectorLayer::addTopologicalPoints ( const QgsPoint p)

Adds a vertex to segments which intersect point p but don't already have a vertex there.

If a feature already has a vertex at position p, no additional vertex is inserted. This method is useful for topological editing.

Parameters
pposition of the vertex
Returns
0 in case of success

Definition at line 1277 of file qgsvectorlayer.cpp.

§ aggregate()

QVariant QgsVectorLayer::aggregate ( QgsAggregateCalculator::Aggregate  aggregate,
const QString &  fieldOrExpression,
const QgsAggregateCalculator::AggregateParameters parameters = QgsAggregateCalculator::AggregateParameters(),
QgsExpressionContext context = nullptr,
bool *  ok = nullptr 
) const

Calculates an aggregated value from the layer's features.

Parameters
aggregateaggregate to calculate
fieldOrExpressionsource field or expression to use as basis for aggregated values.
parametersparameters controlling aggregate calculation
contextexpression context for expressions and filters
okif specified, will be set to true if aggregate calculation was successful
Returns
calculated aggregate value
Note
added in QGIS 2.16

Definition at line 3501 of file qgsvectorlayer.cpp.

§ allFeatureIds()

QgsFeatureIds QgsVectorLayer::allFeatureIds ( ) const

Get all feature Ids.

Definition at line 426 of file qgsvectorlayer.cpp.

§ annotationForm()

QString QgsVectorLayer::annotationForm ( ) const
inline

Get annotation form.

Definition at line 1317 of file qgsvectorlayer.h.

§ attributeAdded

void QgsVectorLayer::attributeAdded ( int  idx)
signal

Will be emitted, when a new attribute has been added to this vector layer.

Applies only to types QgsFields::OriginEdit, QgsFields::OriginProvider and QgsFields::OriginExpression

Parameters
idxThe index of the new attribute
See also
updatedFields()

§ attributeAlias()

QString QgsVectorLayer::attributeAlias ( int  index) const

Returns the alias of an attribute name or a null string if there is no alias.

See also
{attributeDisplayName( int attributeIndex )} which returns the field name if no alias is defined.

Definition at line 2247 of file qgsvectorlayer.cpp.

§ attributeAliases()

QgsStringMap QgsVectorLayer::attributeAliases ( ) const

Returns a map of field name to attribute alias.

Definition at line 2263 of file qgsvectorlayer.cpp.

§ attributeDeleted

void QgsVectorLayer::attributeDeleted ( int  idx)
signal

Will be emitted, when an attribute has been deleted from this vector layer.

Applies only to types QgsFields::OriginEdit, QgsFields::OriginProvider and QgsFields::OriginExpression

Parameters
idxThe index of the deleted attribute
See also
updatedFields()

§ attributeDisplayName()

QString QgsVectorLayer::attributeDisplayName ( int  index) const

Convenience function that returns the attribute alias if defined or the field name else.

Definition at line 2255 of file qgsvectorlayer.cpp.

§ attributeList()

QgsAttributeList QgsVectorLayer::attributeList ( ) const
inline

Returns list of attribute indexes.

i.e. a list from 0 ... fieldCount() Alias for attributeList()

Definition at line 1157 of file qgsvectorlayer.h.

§ attributeTableConfig()

QgsAttributeTableConfig QgsVectorLayer::attributeTableConfig ( ) const

Get the attribute table configuration object.

This defines the appearance of the attribute table.

Definition at line 3925 of file qgsvectorlayer.cpp.

§ attributeValueChanged

void QgsVectorLayer::attributeValueChanged ( QgsFeatureId  fid,
int  idx,
const QVariant &  value 
)
signal

Is emitted whenever an attribute value change is done in the edit buffer.

Note that at this point the attribute change is not yet saved to the provider.

Parameters
fidThe id of the changed feature
idxThe attribute index of the changed attribute
valueThe new value of the attribute

§ beforeAddingExpressionField

void QgsVectorLayer::beforeAddingExpressionField ( const QString &  fieldName)
signal

Will be emitted, when an expression field is going to be added to this vector layer.

Applies only to types QgsFields::OriginExpression

Parameters
fieldNameThe name of the attribute to be added

§ beforeCommitChanges

void QgsVectorLayer::beforeCommitChanges ( )
signal

Is emitted, before changes are commited to the data provider.

§ beforeEditingStarted

void QgsVectorLayer::beforeEditingStarted ( )
signal

Is emitted, before editing on this layer is started.

§ beforeModifiedCheck

void QgsVectorLayer::beforeModifiedCheck ( ) const
signal

Is emitted, when layer is checked for modifications. Use for last-minute additions.

§ beforeRemovingExpressionField

void QgsVectorLayer::beforeRemovingExpressionField ( int  idx)
signal

Will be emitted, when an expression field is going to be deleted from this vector layer.

Applies only to types QgsFields::OriginExpression

Parameters
idxThe index of the attribute to be deleted

§ beforeRollBack

void QgsVectorLayer::beforeRollBack ( )
signal

Is emitted, before changes are rolled back.

§ beginEditCommand()

void QgsVectorLayer::beginEditCommand ( const QString &  text)

Create edit command for undo/redo operations.

Parameters
texttext which is to be displayed in undo window

Definition at line 2828 of file qgsvectorlayer.cpp.

§ boundingBoxOfSelected()

QgsRectangle QgsVectorLayer::boundingBoxOfSelected ( ) const

Returns the bounding box of the selected features. If there is no selection, QgsRectangle(0,0,0,0) is returned.

Definition at line 539 of file qgsvectorlayer.cpp.

§ cache()

QgsGeometryCache* QgsVectorLayer::cache ( )
inline
Note
not available in python bindings

Definition at line 1555 of file qgsvectorlayer.h.

§ capabilitiesString()

QString QgsVectorLayer::capabilitiesString ( ) const

Capabilities for this layer in a friendly format.

Definition at line 203 of file qgsvectorlayer.cpp.

§ changeAttributeValue()

bool QgsVectorLayer::changeAttributeValue ( QgsFeatureId  fid,
int  field,
const QVariant &  newValue,
const QVariant &  oldValue = QVariant() 
)

Changes an attribute value (but does not commit it)

Parameters
fidThe feature id of the feature to be changed
fieldThe index of the field to be updated
newValueThe value which will be assigned to the field
oldValueThe previous value to restore on undo (will otherwise be retrieved)
Returns
true in case of success

Definition at line 2163 of file qgsvectorlayer.cpp.

§ changeGeometry()

bool QgsVectorLayer::changeGeometry ( QgsFeatureId  fid,
const QgsGeometry geom 
)

Change feature's geometry.

Definition at line 2146 of file qgsvectorlayer.cpp.

§ checkJoinLayerRemove

void QgsVectorLayer::checkJoinLayerRemove ( const QString &  theLayerId)
slot

Check if there is a join with a layer that will be removed.

Definition at line 2882 of file qgsvectorlayer.cpp.

§ commitChanges()

bool QgsVectorLayer::commitChanges ( )

Attempts to commit any changes to disk.

Returns the result of the attempt. If a commit fails, the in-memory changes are left alone.

This allows editing to continue if the commit failed on e.g. a disallowed value in a Postgres database - the user can re-edit and try again.

The commits occur in distinct stages, (add attributes, add features, change attribute values, change geometries, delete features, delete attributes) so if a stage fails, it's difficult to roll back cleanly. Therefore any error message also includes which stage failed so that the user has some chance of repairing the damage cleanly.

See also
commitErrors()

Definition at line 2366 of file qgsvectorlayer.cpp.

§ commitErrors()

QStringList QgsVectorLayer::commitErrors ( ) const

Returns a list containing any error messages generated when attempting to commit changes to the layer.

See also
commitChanges()

Definition at line 2413 of file qgsvectorlayer.cpp.

§ committedAttributesAdded

void QgsVectorLayer::committedAttributesAdded ( const QString &  layerId,
const QList< QgsField > &  addedAttributes 
)
signal

This signal is emitted, when attributes are added to the provider.

§ committedAttributesDeleted

void QgsVectorLayer::committedAttributesDeleted ( const QString &  layerId,
const QgsAttributeList deletedAttributes 
)
signal

This signal is emitted, when attributes are deleted from the provider.

§ committedAttributeValuesChanges

void QgsVectorLayer::committedAttributeValuesChanges ( const QString &  layerId,
const QgsChangedAttributesMap changedAttributesValues 
)
signal

This signal is emitted, when attribute value changes are saved to the provider.

§ committedFeaturesAdded

void QgsVectorLayer::committedFeaturesAdded ( const QString &  layerId,
const QgsFeatureList addedFeatures 
)
signal

This signal is emitted, when features are added to the provider.

§ committedFeaturesRemoved

void QgsVectorLayer::committedFeaturesRemoved ( const QString &  layerId,
const QgsFeatureIds deletedFeatureIds 
)
signal

This signal is emitted, when features are deleted from the provider.

§ committedGeometriesChanges

void QgsVectorLayer::committedGeometriesChanges ( const QString &  layerId,
const QgsGeometryMap changedGeometries 
)
signal

This signal is emitted, when geometry changes are saved to the provider.

§ conditionalStyles()

QgsConditionalLayerStyles * QgsVectorLayer::conditionalStyles ( ) const

Return the conditional styles that are set for this layer.

Style information is used to render conditional formatting in the attribute table.

Returns
Return a QgsConditionalLayerStyles object holding the conditional attribute style information. Style information is generic and can be used for anything.
Note
added in QGIS 2.12

Definition at line 942 of file qgsvectorlayer.cpp.

§ constraintDescription()

QString QgsVectorLayer::constraintDescription ( int  index) const

Returns the descriptive name for the constraint expression for a specified field index.

Note
added in QGIS 3.0
See also
constraints()
constraintExpression()
setConstraintExpression()

Definition at line 4497 of file qgsvectorlayer.cpp.

§ constraintExpression()

QString QgsVectorLayer::constraintExpression ( int  index) const

Returns the constraint expression for for a specified field index, if set.

Note
added in QGIS 3.0
See also
fieldConstraints()
constraintDescription()
setConstraintExpression()

Definition at line 4489 of file qgsvectorlayer.cpp.

§ countSymbolFeatures()

bool QgsVectorLayer::countSymbolFeatures ( bool  showProgress = true)

Count features for symbols.

Feature counts may be get by featureCount().

Parameters
showProgressshow progress dialog
Returns
true if calculated, false if failed or was canceled by user

Definition at line 672 of file qgsvectorlayer.cpp.

§ createExpressionContext()

QgsExpressionContext QgsVectorLayer::createExpressionContext ( ) const
overridevirtual

This method needs to be reimplemented in all classes which implement this interface and return an expression context.

Note
Added in QGIS 3.0

Implements QgsExpressionContextGenerator.

Definition at line 3944 of file qgsvectorlayer.cpp.

§ createJoinCaches()

void QgsVectorLayer::createJoinCaches ( ) const

Caches joined attributes if required (and not already done)

Definition at line 3040 of file qgsvectorlayer.cpp.

§ createMapRenderer()

QgsMapLayerRenderer * QgsVectorLayer::createMapRenderer ( QgsRenderContext rendererContext)
overridevirtual

Return new instance of QgsMapLayerRenderer that will be used for rendering of given context.

Note
added in 2.4

Implements QgsMapLayer.

Definition at line 236 of file qgsvectorlayer.cpp.

§ dataComment()

QString QgsVectorLayer::dataComment ( ) const

Returns a comment for the data in the layer.

Definition at line 212 of file qgsvectorlayer.cpp.

§ dataProvider() [1/2]

QgsVectorDataProvider * QgsVectorLayer::dataProvider ( )

Returns the data provider.

Definition at line 480 of file qgsvectorlayer.cpp.

§ dataProvider() [2/2]

const QgsVectorDataProvider * QgsVectorLayer::dataProvider ( ) const

Returns the data provider in a const-correct manner.

Note
not available in python bindings

Definition at line 485 of file qgsvectorlayer.cpp.

§ defaultValue()

QVariant QgsVectorLayer::defaultValue ( int  index,
const QgsFeature feature = QgsFeature(),
QgsExpressionContext context = nullptr 
) const

Returns the calculated default value for the specified field index.

The default value may be taken from a client side default value expression (see setDefaultValueExpression()) or taken from the underlying data provider.

Parameters
indexfield index
featureoptional feature to use for default value evaluation. If passed, then properties from the feature (such as geometry) can be used when calculating the default value.
contextoptional expression context to evaluate expressions again. If not specified, a default context will be created
Returns
calculated default value
Note
added in QGIS 3.0
See also
setDefaultValueExpression()

Definition at line 3048 of file qgsvectorlayer.cpp.

§ defaultValueExpression()

QString QgsVectorLayer::defaultValueExpression ( int  index) const

Returns the expression used when calculating the default value for a field.

Parameters
indexfield index
Returns
expression evaluated when calculating default values for field, or an empty string if no default is set
Note
added in QGIS 3.0
See also
defaultValue()
setDefaultValueExpression()

Definition at line 3113 of file qgsvectorlayer.cpp.

§ deleteAttribute()

bool QgsVectorLayer::deleteAttribute ( int  attr)

Delete an attribute field (but does not commit it)

Definition at line 2274 of file qgsvectorlayer.cpp.

§ deleteAttributes()

bool QgsVectorLayer::deleteAttributes ( QList< int >  attrs)

Deletes a list of attribute fields (but does not commit it)

Parameters
attrsthe indices of the attributes to delete
Returns
true if at least one attribute has been deleted

Definition at line 2291 of file qgsvectorlayer.cpp.

§ deleteFeature()

bool QgsVectorLayer::deleteFeature ( QgsFeatureId  fid)

Delete a feature from the layer (but does not commit it)

Definition at line 2311 of file qgsvectorlayer.cpp.

§ deleteFeatures()

bool QgsVectorLayer::deleteFeatures ( const QgsFeatureIds fids)

Deletes a set of features from the layer (but does not commit it)

Parameters
fidsThe feature ids to delete
Returns
false if the layer is not in edit mode or does not support deleting in case of an active transaction depends on the provider implementation

Definition at line 2326 of file qgsvectorlayer.cpp.

§ deleteSelectedFeatures()

bool QgsVectorLayer::deleteSelectedFeatures ( int *  deletedCount = nullptr)

Deletes the selected features.

Returns
true in case of success and false otherwise

Definition at line 1066 of file qgsvectorlayer.cpp.

§ deleteVertex()

QgsVectorLayer::EditResult QgsVectorLayer::deleteVertex ( QgsFeatureId  featureId,
int  vertex 
)

Deletes a vertex from a feature.

Parameters
featureIdID of feature to remove vertex from
vertexindex of vertex to delete
Note
added in QGIS 2.14

Definition at line 1052 of file qgsvectorlayer.cpp.

§ dependencies()

QSet< QgsMapLayerDependency > QgsVectorLayer::dependencies ( ) const
overridevirtual

Gets the list of dependencies.

This includes data dependencies set by the user (

See also
setDataDependencies) as well as dependencies given by the provider
Returns
a set of QgsMapLayerDependency
Note
added in QGIS 3.0

Reimplemented from QgsMapLayer.

Definition at line 4379 of file qgsvectorlayer.cpp.

§ deselect [1/2]

void QgsVectorLayer::deselect ( const QgsFeatureId  featureId)
slot

Deselect feature by its ID.

Parameters
featureIdThe id of the feature to deselect
See also
deselect(QgsFeatureIds)

Definition at line 272 of file qgsvectorlayer.cpp.

§ deselect [2/2]

void QgsVectorLayer::deselect ( const QgsFeatureIds featureIds)
slot

Deselect features by their ID.

Parameters
featureIdsThe ids of the features to deselect
See also
deselect(QgsFeatureId)

Definition at line 279 of file qgsvectorlayer.cpp.

§ destroyEditCommand()

void QgsVectorLayer::destroyEditCommand ( )

Destroy active command and reverts all changes in it.

Definition at line 2861 of file qgsvectorlayer.cpp.

§ diagramLayerSettings()

const QgsDiagramLayerSettings* QgsVectorLayer::diagramLayerSettings ( ) const
inline

Definition at line 717 of file qgsvectorlayer.h.

§ diagramRenderer()

const QgsDiagramRenderer* QgsVectorLayer::diagramRenderer ( ) const
inline

Definition at line 714 of file qgsvectorlayer.h.

§ diagramsEnabled()

bool QgsVectorLayer::diagramsEnabled ( ) const

Returns whether the layer contains diagrams which are enabled and should be drawn.

Returns
true if layer contains enabled diagrams
Note
added in QGIS 2.9

Definition at line 612 of file qgsvectorlayer.cpp.

§ displayExpression()

QString QgsVectorLayer::displayExpression ( ) const

Get the preview expression, used to create a human readable preview string.

Uses QgsExpression

Returns
The expression which will be used to preview features for this layer

§ displayExpressionChanged

void QgsVectorLayer::displayExpressionChanged ( )
signal

Emitted when the display expression changes.

Note
added in QGIS 3.0

§ displayField()

QString QgsVectorLayer::displayField ( ) const

This is a shorthand for accessing the displayExpression if it is a simple field.

If the displayExpression is more complex than a simple field, a null string will be returned.

See also
displayExpression

Definition at line 2708 of file qgsvectorlayer.cpp.

§ drawVertexMarker()

void QgsVectorLayer::drawVertexMarker ( double  x,
double  y,
QPainter &  p,
QgsVectorLayer::VertexMarkerType  type,
int  vertexSize 
)
static

Draws a vertex symbol at (screen) coordinates x, y. (Useful to assist vertex editing.)

Definition at line 242 of file qgsvectorlayer.cpp.

§ editBuffer() [1/2]

QgsVectorLayerEditBuffer* QgsVectorLayer::editBuffer ( )
inline

Buffer with uncommitted editing operations. Only valid after editing has been turned on.

Definition at line 1331 of file qgsvectorlayer.h.

§ editBuffer() [2/2]

const QgsVectorLayerEditBuffer* QgsVectorLayer::editBuffer ( ) const
inline

Buffer with uncommitted editing operations. Only valid after editing has been turned on.

Definition at line 1334 of file qgsvectorlayer.h.

§ editCommandDestroyed

void QgsVectorLayer::editCommandDestroyed ( )
signal

Signal emitted, whan an edit command is destroyed.

Note
This is not a rollback, it is only related to the current edit command. See beforeRollBack()

§ editCommandEnded

void QgsVectorLayer::editCommandEnded ( )
signal

Signal emitted, when an edit command successfully ended.

Note
This does not mean it is also committed, only that it is written to the edit buffer. See beforeCommitChanges()

§ editCommandStarted

void QgsVectorLayer::editCommandStarted ( const QString &  text)
signal

Signal emitted when a new edit command has been started.

Parameters
textDescription for this edit command

§ editFormConfig()

QgsEditFormConfig QgsVectorLayer::editFormConfig ( ) const

Get the configuration of the form used to represent this vector layer.

This is a writable configuration that can directly be changed in place.

Returns
The configuration of this layers' form
Note
Added in QGIS 2.14

§ editFormConfigChanged

void QgsVectorLayer::editFormConfigChanged ( )
signal

Will be emitted whenever the edit form configuration of this layer changes.

Note
added in QGIS 3.0

§ editingStarted

void QgsVectorLayer::editingStarted ( )
signal

Is emitted, when editing on this layer has started.

§ editingStopped

void QgsVectorLayer::editingStopped ( )
signal

Is emitted, when edited changes successfully have been written to the data provider.

§ endEditCommand()

void QgsVectorLayer::endEditCommand ( )

Finish edit command and add it to undo/redo stack.

Definition at line 2842 of file qgsvectorlayer.cpp.

§ excludeAttributesWfs()

const QSet<QString>& QgsVectorLayer::excludeAttributesWfs ( ) const
inline

A set of attributes that are not advertised in WFS requests with QGIS server.

Definition at line 1253 of file qgsvectorlayer.h.

§ excludeAttributesWms()

const QSet<QString>& QgsVectorLayer::excludeAttributesWms ( ) const
inline

A set of attributes that are not advertised in WMS requests with QGIS server.

Definition at line 1243 of file qgsvectorlayer.h.

§ expressionField()

QString QgsVectorLayer::expressionField ( int  index) const

Returns the expression used for a given expression field.

Parameters
indexAn index of an epxression based (virtual) field
Returns
The expression for the field at index
Note
added in 2.9

Definition at line 2924 of file qgsvectorlayer.cpp.

§ extent()

QgsRectangle QgsVectorLayer::extent ( ) const
overridevirtual

Return the extent of the layer.

Reimplemented from QgsMapLayer.

Definition at line 808 of file qgsvectorlayer.cpp.

§ featureAdded

void QgsVectorLayer::featureAdded ( QgsFeatureId  fid)
signal

Emitted when a new feature has been added to the layer.

Parameters
fidThe id of the new feature

§ featureBlendMode()

QPainter::CompositionMode QgsVectorLayer::featureBlendMode ( ) const

Returns the current blending mode for features.

Read blend mode for layer.

Definition at line 3641 of file qgsvectorlayer.cpp.

§ featureBlendModeChanged

void QgsVectorLayer::featureBlendModeChanged ( QPainter::CompositionMode  blendMode)
signal

Signal emitted when setFeatureBlendMode() is called.

§ featureCount() [1/2]

long QgsVectorLayer::featureCount ( const QString &  legendKey) const

Number of features rendered with specified legend key.

Features must be first calculated by countSymbolFeatures()

Returns
number of features rendered by symbol or -1 if failed or counts are not available

Definition at line 625 of file qgsvectorlayer.cpp.

§ featureCount() [2/2]

long QgsVectorLayer::featureCount ( ) const

Returns feature count including changes which have not yet been committed If you need only the count of committed features call this method on this layer's provider.

Definition at line 2360 of file qgsvectorlayer.cpp.

§ featureDeleted

void QgsVectorLayer::featureDeleted ( QgsFeatureId  fid)
signal

Emitted when a feature has been deleted.

If you do expensive operations in a slot connected to this, you should prever to use featuresDeleted( const QgsFeatureIds& ).

Parameters
fidThe id of the feature which has been deleted

§ featuresDeleted

void QgsVectorLayer::featuresDeleted ( const QgsFeatureIds fids)
signal

Emitted when features have been deleted.

If features are deleted within an edit command, this will only be emitted once at the end to allow connected slots to minimize the overhead. If features are deleted outside of an edit command, this signal will be emitted once per feature.

Parameters
fidsThe feature ids that have been deleted.

§ fieldConstraints()

QgsFieldConstraints::Constraints QgsVectorLayer::fieldConstraints ( int  fieldIndex) const

Returns any constraints which are present for a specified field index.

These constraints may be inherited from the layer's data provider or may be set manually on the vector layer from within QGIS.

Note
added in QGIS 3.0
See also
setFieldConstraint()

Definition at line 4439 of file qgsvectorlayer.cpp.

§ fields()

QgsFields QgsVectorLayer::fields ( ) const
inline

Returns the list of fields of this layer.

This also includes fields which have not yet been saved to the provider.

Returns
A list of fields

Definition at line 1136 of file qgsvectorlayer.h.

§ geometryChanged

void QgsVectorLayer::geometryChanged ( QgsFeatureId  fid,
const QgsGeometry geometry 
)
signal

Is emitted whenever a geometry change is done in the edit buffer.

Note that at this point the geometry change is not yet saved to the provider.

Parameters
fidThe id of the changed feature
geometryThe new geometry

§ geometryType()

QgsWkbTypes::GeometryType QgsVectorLayer::geometryType ( ) const

Returns point, line or polygon.

Definition at line 507 of file qgsvectorlayer.cpp.

§ getDoubleValues()

QList< double > QgsVectorLayer::getDoubleValues ( const QString &  fieldOrExpression,
bool &  ok,
bool  selectedOnly = false,
int *  nullCount = nullptr 
) const

Fetches all double values from a specified field name or expression.

Null values or invalid expression results are skipped.

Parameters
fieldOrExpressionfield name or an expression string evaluating to a double value
okwill be set to false if field or expression is invalid, otherwise true
selectedOnlyset to true to get values from selected features only
nullCountoptional pointer to integer to store number of null values encountered in
Returns
list of fetched values
Note
added in QGIS 2.9
See also
getValues

Definition at line 3604 of file qgsvectorlayer.cpp.

§ getFeature()

QgsFeature QgsVectorLayer::getFeature ( QgsFeatureId  fid)
inline

Query the layer for the feature with the given id.

If there is no such feature, the returned feature will be invalid.

Definition at line 899 of file qgsvectorlayer.h.

§ getFeatures() [1/4]

QgsFeatureIterator QgsVectorLayer::getFeatures ( const QgsFeatureRequest request = QgsFeatureRequest()) const

Query the layer for features specified in request.

Parameters
requestfeature request describing parameters of features to return
Returns
iterator for matching features from provider

Definition at line 947 of file qgsvectorlayer.cpp.

§ getFeatures() [2/4]

QgsFeatureIterator QgsVectorLayer::getFeatures ( const QString &  expression)
inline

Query the layer for features matching a given expression.

Definition at line 890 of file qgsvectorlayer.h.

§ getFeatures() [3/4]

QgsFeatureIterator QgsVectorLayer::getFeatures ( const QgsFeatureIds fids)
inline

Query the layer for the features with the given ids.

Definition at line 909 of file qgsvectorlayer.h.

§ getFeatures() [4/4]

QgsFeatureIterator QgsVectorLayer::getFeatures ( const QgsRectangle rectangle)
inline

Query the layer for the features which intersect the specified rectangle.

Definition at line 917 of file qgsvectorlayer.h.

§ getStyleFromDatabase()

QString QgsVectorLayer::getStyleFromDatabase ( const QString &  styleId,
QString &  msgError 
)
virtual

Will return the named style corresponding to style id provided.

Definition at line 4282 of file qgsvectorlayer.cpp.

§ getValues()

QList< QVariant > QgsVectorLayer::getValues ( const QString &  fieldOrExpression,
bool &  ok,
bool  selectedOnly = false 
) const

Fetches all values from a specified field name or expression.

Parameters
fieldOrExpressionfield name or an expression string
okwill be set to false if field or expression is invalid, otherwise true
selectedOnlyset to true to get values from selected features only
Returns
list of fetched values
Note
added in QGIS 2.9
See also
getDoubleValues

Definition at line 3539 of file qgsvectorlayer.cpp.

§ hasGeometryType()

bool QgsVectorLayer::hasGeometryType ( ) const

Returns true if this is a geometry layer and false in case of NoGeometry (table only) or UnknownGeometry.

Definition at line 528 of file qgsvectorlayer.cpp.

§ insertSegmentVerticesForSnap()

int QgsVectorLayer::insertSegmentVerticesForSnap ( const QList< QgsSnappingResult > &  snapResults)

Inserts vertices to the snapped segments.

This is useful for topological editing if snap to segment is enabled.

Parameters
snapResultsresults collected from the snapping operation
Returns
0 in case of success

Definition at line 2680 of file qgsvectorlayer.cpp.

§ insertVertex()

bool QgsVectorLayer::insertVertex ( double  x,
double  y,
QgsFeatureId  atFeatureId,
int  beforeVertex 
)

Insert a new vertex before the given vertex number, in the given ring, item (first number is index 0), and feature Not meaningful for Point geometries.

Definition at line 1013 of file qgsvectorlayer.cpp.

§ invalidateSymbolCountedFlag

void QgsVectorLayer::invalidateSymbolCountedFlag ( )
protectedslot

Definition at line 4230 of file qgsvectorlayer.cpp.

§ invertSelection()

void QgsVectorLayer::invertSelection ( )

Select not selected features and deselect selected ones.

Definition at line 414 of file qgsvectorlayer.cpp.

§ invertSelectionInRectangle()

void QgsVectorLayer::invertSelectionInRectangle ( QgsRectangle rect)

Invert selection of features found within the search rectangle (in layer's coordinates)

Parameters
rectThe rectangle in which the selection of features will be inverted
See also
invertSelection()

Definition at line 443 of file qgsvectorlayer.cpp.

§ isEditable()

bool QgsVectorLayer::isEditable ( ) const
overridevirtual

Returns true if the provider is in editing mode.

Reimplemented from QgsMapLayer.

Definition at line 2774 of file qgsvectorlayer.cpp.

§ isModified()

bool QgsVectorLayer::isModified ( ) const
virtual

Returns true if the provider has been modified since the last commit.

Definition at line 2800 of file qgsvectorlayer.cpp.

§ isSpatial()

bool QgsVectorLayer::isSpatial ( ) const
overridevirtual

Returns true if the layer is considered a spatial layer, ie it has some form of geometry associated with it.

Note
added in QGIS 2.16

Reimplemented from QgsMapLayer.

Definition at line 2779 of file qgsvectorlayer.cpp.

§ joinBuffer()

QgsVectorLayerJoinBuffer* QgsVectorLayer::joinBuffer ( )
inline

Acccessor to the join buffer object.

Note
added 2.14.7

Definition at line 522 of file qgsvectorlayer.h.

§ labeling()

const QgsAbstractVectorLayerLabeling* QgsVectorLayer::labeling ( ) const
inline

Access to labeling configuration.

Note
added in 2.12
not available in Python bindings

Definition at line 1083 of file qgsvectorlayer.h.

§ labelingFontNotFound

void QgsVectorLayer::labelingFontNotFound ( QgsVectorLayer layer,
const QString &  fontfamily 
)
signal

Emitted when the font family defined for labeling layer is not found on system.

§ labelsEnabled()

bool QgsVectorLayer::labelsEnabled ( ) const

Returns whether the layer contains labels which are enabled and should be drawn.

Returns
true if layer contains enabled labels
Note
added in QGIS 2.9

Definition at line 598 of file qgsvectorlayer.cpp.

§ layerModified

void QgsVectorLayer::layerModified ( )
signal

This signal is emitted when modifications has been done on layer.

§ layerTransparency()

int QgsVectorLayer::layerTransparency ( ) const

Returns the current transparency for the vector layer.

Read transparency for layer.

Definition at line 3655 of file qgsvectorlayer.cpp.

§ layerTransparencyChanged

void QgsVectorLayer::layerTransparencyChanged ( int  layerTransparency)
signal

Signal emitted when setLayerTransparency() is called.

§ listStylesInDatabase()

int QgsVectorLayer::listStylesInDatabase ( QStringList &  ids,
QStringList &  names,
QStringList &  descriptions,
QString &  msgError 
)
virtual

Lists all the style in db split into related to the layer and not related to.

Parameters
idsthe list in which will be stored the style db ids
namesthe list in which will be stored the style names
descriptionsthe list in which will be stored the style descriptions
msgError
Returns
the number of styles related to current layer

Definition at line 4261 of file qgsvectorlayer.cpp.

§ loadNamedStyle() [1/2]

QString QgsVectorLayer::loadNamedStyle ( const QString &  theURI,
bool &  theResultFlag,
bool  loadFromLocalDb 
)
virtual

Load a named style from file/local db/datasource db.

Parameters
theURIthe URI of the style or the URI of the layer
theResultFlagwill be set to true if a named style is correctly loaded
loadFromLocalDbif true forces to load from local db instead of datasource one

Definition at line 4351 of file qgsvectorlayer.cpp.

§ loadNamedStyle() [2/2]

QString QgsVectorLayer::loadNamedStyle ( const QString &  theURI,
bool &  theResultFlag 
)
overridevirtual

Calls loadNamedStyle( theURI, theResultFlag, false ); Retained for backward compatibility.

Reimplemented from QgsMapLayer.

Definition at line 4346 of file qgsvectorlayer.cpp.

§ mapTipTemplate()

QString QgsVectorLayer::mapTipTemplate ( ) const

The mapTip is a pretty, html representation for feature information.

It may also contain embedded expressions.

Note
added in 3.0

§ mapTipTemplateChanged

void QgsVectorLayer::mapTipTemplateChanged ( )
signal

Emitted when the map tip changes.

Note
added in QGIS 3.0

§ maximumValue()

QVariant QgsVectorLayer::maximumValue ( int  index) const

Returns the maximum value for an attribute column or an invalid variant in case of error.

Note that in some circumstances when unsaved changes are present for the layer then the returned value may be outdated (for instance when the attribute value in a saved feature has been changed inside the edit buffer then the previous saved value may be returned as the maximum).

See also
minimumValue()
uniqueValues()

Definition at line 3416 of file qgsvectorlayer.cpp.

§ metadata()

QString QgsVectorLayer::metadata ( ) const
overridevirtual

Obtain Metadata for this layer.

Reimplemented from QgsMapLayer.

Definition at line 3961 of file qgsvectorlayer.cpp.

§ minimumValue()

QVariant QgsVectorLayer::minimumValue ( int  index) const

Returns the minimum value for an attribute column or an invalid variant in case of error.

Note that in some circumstances when unsaved changes are present for the layer then the returned value may be outdated (for instance when the attribute value in a saved feature has been changed inside the edit buffer then the previous saved value may be returned as the minimum).

See also
maximumValue()
uniqueValues()

Definition at line 3328 of file qgsvectorlayer.cpp.

§ modifySelection()

void QgsVectorLayer::modifySelection ( const QgsFeatureIds selectIds,
const QgsFeatureIds deselectIds 
)

Modifies the current selection on this layer.

Parameters
selectIdsSelect these ids
deselectIdsDeselect these ids
See also
select(QgsFeatureIds)
select(QgsFeatureId)
deselect(QgsFeatureIds)
deselect(QgsFeatureId)
selectByExpression()

Definition at line 400 of file qgsvectorlayer.cpp.

§ moveVertex() [1/2]

bool QgsVectorLayer::moveVertex ( double  x,
double  y,
QgsFeatureId  atFeatureId,
int  atVertex 
)

Moves the vertex at the given position number, ring and item (first number is index 0), and feature to the given coordinates.

Definition at line 1026 of file qgsvectorlayer.cpp.

§ moveVertex() [2/2]

bool QgsVectorLayer::moveVertex ( const QgsPointV2 p,
QgsFeatureId  atFeatureId,
int  atVertex 
)

Moves the vertex at the given position number, ring and item (first number is index 0), and feature to the given coordinates.

Note
available in python as moveVertexV2

Definition at line 1039 of file qgsvectorlayer.cpp.

§ pendingAllAttributesList()

QgsAttributeList QgsVectorLayer::pendingAllAttributesList ( ) const
inline

Returns list of attribute indexes.

i.e. a list from 0 ... fieldCount() Alias for attributeList()

Definition at line 1151 of file qgsvectorlayer.h.

§ pendingFeatureCount()

long QgsVectorLayer::pendingFeatureCount ( ) const
inline

Returns feature count including changes which have not yet been committed Alias for featureCount().

Definition at line 1172 of file qgsvectorlayer.h.

§ pendingFields()

QgsFields QgsVectorLayer::pendingFields ( ) const
inline

Returns the list of fields of this layer.

This also includes fields which have not yet been saved to the provider. Alias for fields()

Returns
A list of fields

Definition at line 1145 of file qgsvectorlayer.h.

§ pendingPkAttributesList()

QgsAttributeList QgsVectorLayer::pendingPkAttributesList ( ) const
inline

Returns list of attributes making up the primary key Alias for pkAttributeList().

Definition at line 1163 of file qgsvectorlayer.h.

§ pkAttributeList()

QgsAttributeList QgsVectorLayer::pkAttributeList ( ) const

Returns list of attributes making up the primary key.

Definition at line 2345 of file qgsvectorlayer.cpp.

§ providerType()

QString QgsVectorLayer::providerType ( ) const

Return the provider type for this layer.

Definition at line 222 of file qgsvectorlayer.cpp.

§ raiseError

void QgsVectorLayer::raiseError ( const QString &  msg)
signal

Signals an error related to this vector layer.

§ readCustomSymbology

void QgsVectorLayer::readCustomSymbology ( const QDomElement &  element,
QString &  errorMessage 
)
signal

Signal emitted whenever the symbology (QML-file) for this layer is being read.

If there is custom style information saved in the file, you can connect to this signal and update the layer style accordingly.

Parameters
elementThe XML layer style element.
errorMessageWrite error messages into this string.

§ readOnlyChanged

void QgsVectorLayer::readOnlyChanged ( )
signal

Emitted when the read only state of this layer is changed.

Only applies to manually set readonly state, not to the edit mode.

Note
Added in QGIS 3.0

§ readSld()

bool QgsVectorLayer::readSld ( const QDomNode &  node,
QString &  errorMessage 
)
overridevirtual

Reimplemented from QgsMapLayer.

Definition at line 2100 of file qgsvectorlayer.cpp.

§ readStyle()

bool QgsVectorLayer::readStyle ( const QDomNode &  node,
QString &  errorMessage 
)
overridevirtual

Read the style for the current layer from the Dom node supplied.

Parameters
nodenode that will contain the style definition for this layer.
errorMessagereference to string that will be updated with any error messages
Returns
true in case of success.

Reimplemented from QgsMapLayer.

Definition at line 1847 of file qgsvectorlayer.cpp.

§ readSymbology()

bool QgsVectorLayer::readSymbology ( const QDomNode &  node,
QString &  errorMessage 
)
overridevirtual

Read the symbology for the current layer from the Dom node supplied.

Parameters
nodenode that will contain the symbology definition for this layer.
errorMessagereference to string that will be updated with any error messages
Returns
true in case of success.

Implements QgsMapLayer.

Definition at line 1746 of file qgsvectorlayer.cpp.

§ readXml()

bool QgsVectorLayer::readXml ( const QDomNode &  layer_node)
overridevirtual

Reads vector layer specific state from project file Dom node.

Note
Called by QgsMapLayer::readXml().

Reimplemented from QgsMapLayer.

Definition at line 1355 of file qgsvectorlayer.cpp.

§ referencingRelations()

QList< QgsRelation > QgsVectorLayer::referencingRelations ( int  idx) const

Get relations, where the foreign key is on this layer.

Parameters
idxOnly get relations, where idx forms part of the foreign key
Returns
A list of relations

Definition at line 4256 of file qgsvectorlayer.cpp.

§ reload()

void QgsVectorLayer::reload ( )
overridevirtual

Synchronises with changes in the datasource.

Reimplemented from QgsMapLayer.

Definition at line 227 of file qgsvectorlayer.cpp.

§ removeExpressionField()

void QgsVectorLayer::removeExpressionField ( int  index)

Remove an expression field.

Parameters
indexThe index of the field
Note
added in 2.6

Definition at line 2915 of file qgsvectorlayer.cpp.

§ removeFieldAlias()

void QgsVectorLayer::removeFieldAlias ( int  index)

Removes an alias (a display name) for attributes to display in dialogs.

Note
Added in QGIS 3.0

Definition at line 2179 of file qgsvectorlayer.cpp.

§ removeFieldConstraint()

void QgsVectorLayer::removeFieldConstraint ( int  index,
QgsFieldConstraints::Constraint  constraint 
)

Removes a constraint for a specified field index.

Any constraints inherited from the layer's data provider will be kept intact and cannot be removed.

Note
added in QGIS 3.0
See also
fieldConstraints()
setFieldConstraint()

Definition at line 4472 of file qgsvectorlayer.cpp.

§ removeJoin()

bool QgsVectorLayer::removeJoin ( const QString &  joinLayerId)

Removes a vector layer join.

Returns
true if join was found and successfully removed

Definition at line 2887 of file qgsvectorlayer.cpp.

§ removeSelection

void QgsVectorLayer::removeSelection ( )
slot

Clear selection.

See also
selectByIds()

Definition at line 472 of file qgsvectorlayer.cpp.

§ renameAttribute()

bool QgsVectorLayer::renameAttribute ( int  index,
const QString &  newName 
)

Renames an attribute field (but does not commit it).

Parameters
indexattribute index
newNamenew name of field
Note
added in QGIS 2.16

Definition at line 2195 of file qgsvectorlayer.cpp.

§ renderer() [1/2]

QgsFeatureRenderer* QgsVectorLayer::renderer ( )
inline

Return renderer.

Definition at line 720 of file qgsvectorlayer.h.

§ renderer() [2/2]

const QgsFeatureRenderer* QgsVectorLayer::renderer ( ) const
inline

Return const renderer.

Note
not available in python bindings

Definition at line 725 of file qgsvectorlayer.h.

§ rollBack()

bool QgsVectorLayer::rollBack ( bool  deleteBuffer = true)

Stop editing and discard the edits.

Parameters
deleteBufferwhether to delete editing buffer

Definition at line 2418 of file qgsvectorlayer.cpp.

§ saveStyleToDatabase()

void QgsVectorLayer::saveStyleToDatabase ( const QString &  name,
const QString &  description,
bool  useAsDefault,
const QString &  uiFileContent,
QString &  msgError 
)
virtual

Save named and sld style of the layer to the style table in the db.

Parameters
name
description
useAsDefault
uiFileContent
msgError

Definition at line 4304 of file qgsvectorlayer.cpp.

§ select [1/2]

void QgsVectorLayer::select ( QgsFeatureId  featureId)
slot

Select feature by its ID.

Parameters
featureIdThe id of the feature to select
See also
select(QgsFeatureIds)

Definition at line 258 of file qgsvectorlayer.cpp.

§ select [2/2]

void QgsVectorLayer::select ( const QgsFeatureIds featureIds)
slot

Select features by their ID.

Parameters
featureIdsThe ids of the features to select
See also
select(QgsFeatureId)

Definition at line 265 of file qgsvectorlayer.cpp.

§ selectAll()

void QgsVectorLayer::selectAll ( )

Select all the features.

Definition at line 421 of file qgsvectorlayer.cpp.

§ selectByExpression()

void QgsVectorLayer::selectByExpression ( const QString &  expression,
QgsVectorLayer::SelectBehaviour  behaviour = SetSelection 
)

Select matching features using an expression.

Parameters
expressionexpression to evaluate to select features
behaviourselection type, allows adding to current selection, removing from selection, etc.
Note
added in QGIS 2.16
See also
selectByRect()
selectByIds()

Definition at line 308 of file qgsvectorlayer.cpp.

§ selectByIds()

void QgsVectorLayer::selectByIds ( const QgsFeatureIds ids,
QgsVectorLayer::SelectBehaviour  behaviour = SetSelection 
)

Select matching features using a list of feature IDs.

Will emit the selectionChanged() signal with the clearAndSelect flag set.

Parameters
idsfeature IDs to select
behaviourselection type, allows adding to current selection, removing from selection, etc.
Note
added in QGIS 2.16
See also
selectByRect()
selectByExpression()

Definition at line 371 of file qgsvectorlayer.cpp.

§ selectByRect()

void QgsVectorLayer::selectByRect ( QgsRectangle rect,
QgsVectorLayer::SelectBehaviour  behaviour = SetSelection 
)

Select features found within the search rectangle (in layer's coordinates)

Parameters
rectsearch rectangle
behaviourselection type, allows adding to current selection, removing from selection, etc.
See also
invertSelectionInRectangle(QgsRectangle & rect)
selectByExpression()
selectByIds()

Definition at line 286 of file qgsvectorlayer.cpp.

§ selectedFeatureCount()

int QgsVectorLayer::selectedFeatureCount ( ) const

The number of features that are selected in this layer.

Returns
See description

Definition at line 2464 of file qgsvectorlayer.cpp.

§ selectedFeatures()

QgsFeatureList QgsVectorLayer::selectedFeatures ( ) const

Get a copy of the user-selected features.

Returns
A list of QgsFeature 's
See also
selectedFeaturesIds()
selectedFeaturesIterator() which is more memory friendly when handling large selections

Definition at line 2474 of file qgsvectorlayer.cpp.

§ selectedFeaturesIds()

const QgsFeatureIds & QgsVectorLayer::selectedFeaturesIds ( ) const

Return reference to identifiers of selected features.

Returns
A list of QgsFeatureId 's
See also
selectedFeatures()

Definition at line 2469 of file qgsvectorlayer.cpp.

§ selectedFeaturesIterator()

QgsFeatureIterator QgsVectorLayer::selectedFeaturesIterator ( QgsFeatureRequest  request = QgsFeatureRequest()) const

Get an iterator of the selected features.

Parameters
requestYou may specify a request, e.g. to limit the set of requested attributes. Any filter on the request will be discarded.
Returns
Iterator over the selected features
See also
selectedFeaturesIds()
selectedFeatures()

Definition at line 2502 of file qgsvectorlayer.cpp.

§ selectionChanged

void QgsVectorLayer::selectionChanged ( const QgsFeatureIds selected,
const QgsFeatureIds deselected,
const bool  clearAndSelect 
)
signal

This signal is emitted when selection was changed.

Parameters
selectedNewly selected feature ids
deselectedIds of all features which have previously been selected but are not any more
clearAndSelectIn case this is set to true, the old selection was dismissed and the new selection corresponds to selected

§ setAnnotationForm()

void QgsVectorLayer::setAnnotationForm ( const QString &  ui)

Set annotation form for layer.

Definition at line 2806 of file qgsvectorlayer.cpp.

§ setAttributeTableConfig()

void QgsVectorLayer::setAttributeTableConfig ( const QgsAttributeTableConfig attributeTableConfig)

Set the attribute table configuration object.

This defines the appearance of the attribute table.

Definition at line 3935 of file qgsvectorlayer.cpp.

§ setConstraintExpression()

void QgsVectorLayer::setConstraintExpression ( int  index,
const QString &  expression,
const QString &  description = QString() 
)

Set the constraint expression for the specified field index.

An optional descriptive name for the constraint can also be set. Setting an empty expression will clear any existing expression constraint.

Note
added in QGIS 3.0
See also
constraintExpression()
constraintDescription()
constraints()

Definition at line 4505 of file qgsvectorlayer.cpp.

§ setCoordinateSystem()

void QgsVectorLayer::setCoordinateSystem ( )

Setup the coordinate system transformation for the layer.

Definition at line 2687 of file qgsvectorlayer.cpp.

§ setDataSource()

void QgsVectorLayer::setDataSource ( const QString &  dataSource,
const QString &  baseName,
const QString &  provider,
bool  loadDefaultStyleFlag = false 
)

Update the data source of the layer.

The layer's renderer and legend will be preserved only if the geometry type of the new data source matches the current geometry type of the layer.

Parameters
dataSourcenew layer data source
baseNamebase name of the layer
providerprovider string
loadDefaultStyleFlagset to true to reset the layer's style to the default for the data source
Note
added in QGIS 2.10

Definition at line 1510 of file qgsvectorlayer.cpp.

§ setDefaultValueExpression()

void QgsVectorLayer::setDefaultValueExpression ( int  index,
const QString &  expression 
)

Sets an expression to use when calculating the default value for a field.

Parameters
indexfield index
expressionexpression to evaluate when calculating default values for field. Pass an empty expression to clear the default.
Note
added in QGIS 3.0
See also
defaultValue()
defaultValueExpression()

Definition at line 3097 of file qgsvectorlayer.cpp.

§ setDependencies()

bool QgsVectorLayer::setDependencies ( const QSet< QgsMapLayerDependency > &  layers)
overridevirtual

Sets the list of dependencies.

See also
dependencies()
Parameters
layersset of QgsMapLayerDependency. Only user-defined dependencies will be added
Returns
false if a dependency cycle has been detected
Note
added in QGIS 3.0

Reimplemented from QgsMapLayer.

Definition at line 4386 of file qgsvectorlayer.cpp.

§ setDiagramLayerSettings()

void QgsVectorLayer::setDiagramLayerSettings ( const QgsDiagramLayerSettings s)

Definition at line 3954 of file qgsvectorlayer.cpp.

§ setDiagramRenderer()

void QgsVectorLayer::setDiagramRenderer ( QgsDiagramRenderer r)

Sets diagram rendering object (takes ownership)

Definition at line 499 of file qgsvectorlayer.cpp.

§ setDisplayExpression()

void QgsVectorLayer::setDisplayExpression ( const QString &  displayExpression)

Set the preview expression, used to create a human readable preview string.

Used e.g. in the attribute table feature list. Uses QgsExpression.

Parameters
displayExpressionThe expression which will be used to preview features for this layer

Definition at line 2719 of file qgsvectorlayer.cpp.

§ setEditFormConfig()

void QgsVectorLayer::setEditFormConfig ( const QgsEditFormConfig editFormConfig)

Get the configuration of the form used to represent this vector layer.

This is a writable configuration that can directly be changed in place.

Returns
The configuration of this layers' form
Note
Added in QGIS 3.0

Definition at line 3902 of file qgsvectorlayer.cpp.

§ setExcludeAttributesWfs()

void QgsVectorLayer::setExcludeAttributesWfs ( const QSet< QString > &  att)
inline

A set of attributes that are not advertised in WFS requests with QGIS server.

Definition at line 1258 of file qgsvectorlayer.h.

§ setExcludeAttributesWms()

void QgsVectorLayer::setExcludeAttributesWms ( const QSet< QString > &  att)
inline

A set of attributes that are not advertised in WMS requests with QGIS server.

Definition at line 1248 of file qgsvectorlayer.h.

§ setExtent()

void QgsVectorLayer::setExtent ( const QgsRectangle rect)
overrideprotectedvirtual

Set the extent.

Reimplemented from QgsMapLayer.

Definition at line 802 of file qgsvectorlayer.cpp.

§ setFeatureBlendMode()

void QgsVectorLayer::setFeatureBlendMode ( QPainter::CompositionMode  blendMode)

Set the blending mode used for rendering each feature.

Write blend mode for features.

Definition at line 3633 of file qgsvectorlayer.cpp.

§ setFieldAlias()

void QgsVectorLayer::setFieldAlias ( int  index,
const QString &  aliasString 
)

Sets an alias (a display name) for attributes to display in dialogs.

Note
Added in QGIS 3.0

Definition at line 2234 of file qgsvectorlayer.cpp.

§ setFieldConstraint()

void QgsVectorLayer::setFieldConstraint ( int  index,
QgsFieldConstraints::Constraint  constraint,
QgsFieldConstraints::ConstraintStrength  strength = QgsFieldConstraints::ConstraintStrengthHard 
)

Sets a constraint for a specified field index.

Any constraints inherited from the layer's data provider will be kept intact and cannot be modified. Ie, calling this method only allows for new constraints to be added on top of the existing provider constraints.

Note
added in QGIS 3.0
See also
fieldConstraints()
removeFieldConstraint()

Definition at line 4455 of file qgsvectorlayer.cpp.

§ setLabeling()

void QgsVectorLayer::setLabeling ( QgsAbstractVectorLayerLabeling labeling)

Set labeling configuration.

Takes ownership of the object.

Note
added in 2.12
not available in Python bindings

Definition at line 1286 of file qgsvectorlayer.cpp.

§ setLayerTransparency()

void QgsVectorLayer::setLayerTransparency ( int  layerTransparency)

Set the transparency for the vector layer.

Write transparency for layer.

Definition at line 3647 of file qgsvectorlayer.cpp.

§ setMapTipTemplate()

void QgsVectorLayer::setMapTipTemplate ( const QString &  mapTipTemplate)

The mapTip is a pretty, html representation for feature information.

It may also contain embedded expressions.

Note
added in 3.0

Definition at line 3916 of file qgsvectorlayer.cpp.

§ setProviderEncoding()

void QgsVectorLayer::setProviderEncoding ( const QString &  encoding)

Sets the textencoding of the data provider.

Definition at line 490 of file qgsvectorlayer.cpp.

§ setReadOnly()

bool QgsVectorLayer::setReadOnly ( bool  readonly = true)

Make layer read-only (editing disabled) or not.

Returns
false if the layer is in editing yet

Definition at line 2789 of file qgsvectorlayer.cpp.

§ setRenderer()

void QgsVectorLayer::setRenderer ( QgsFeatureRenderer r)

Set renderer which will be invoked to represent this layer.

Ownership is transferred.

Definition at line 2811 of file qgsvectorlayer.cpp.

§ setSimplifyMethod()

void QgsVectorLayer::setSimplifyMethod ( const QgsVectorSimplifyMethod simplifyMethod)
inline

Set the simplification settings for fast rendering of features.

Note
added in 2.2

Definition at line 1560 of file qgsvectorlayer.h.

§ setSubsetString()

bool QgsVectorLayer::setSubsetString ( const QString &  subset)
virtual

Set the string (typically sql) used to define a subset of the layer.

Parameters
subsetThe subset string. This may be the where clause of a sql statement or other defintion string specific to the underlying dataprovider and data store.
Returns
true, when setting the subset string was successful, false otherwise

Definition at line 906 of file qgsvectorlayer.cpp.

§ simplifyDrawingCanbeApplied()

bool QgsVectorLayer::simplifyDrawingCanbeApplied ( const QgsRenderContext renderContext,
QgsVectorSimplifyMethod::SimplifyHint  simplifyHint 
) const

Returns whether the VectorLayer can apply the specified simplification hint.

Note
Do not use in 3rd party code - may be removed in future version!
added in 2.2

Definition at line 927 of file qgsvectorlayer.cpp.

§ simplifyMethod()

const QgsVectorSimplifyMethod& QgsVectorLayer::simplifyMethod ( ) const
inline

Returns the simplification settings for fast rendering of features.

Note
added in 2.2

Definition at line 1565 of file qgsvectorlayer.h.

§ snapPoint()

bool QgsVectorLayer::snapPoint ( QgsPoint point,
double  tolerance 
)

Snaps a point to the closest vertex if there is one within the snapping tolerance.

Parameters
pointThe point which is set to the position of a vertex if there is one within the snapping tolerance. If there is no point within this tolerance, point is left unchanged.
toleranceThe snapping tolerance
Returns
true if the point has been snapped, false if no vertex within search tolerance

Definition at line 2541 of file qgsvectorlayer.cpp.

§ snapWithContext()

int QgsVectorLayer::snapWithContext ( const QgsPoint startPoint,
double  snappingTolerance,
QMultiMap< double, QgsSnappingResult > &  snappingResults,
QgsSnapper::SnappingType  snap_to 
)

Snaps to segment or vertex within given tolerance.

Parameters
startPointpoint to snap (in layer coordinates)
snappingTolerancedistance tolerance for snapping
snappingResultssnapping results. Key is the distance between startPoint and snapping target
snap_toto segment / to vertex
Returns
0 in case of success

Definition at line 2566 of file qgsvectorlayer.cpp.

§ splitFeatures()

int QgsVectorLayer::splitFeatures ( const QList< QgsPoint > &  splitLine,
bool  topologicalEditing = false 
)

Splits features cut by the given line.

Parameters
splitLineline that splits the layer features
topologicalEditingtrue if topological editing is enabled
Returns
0 in case of success, 4 if there is a selection but no feature split

Definition at line 1259 of file qgsvectorlayer.cpp.

§ splitParts()

int QgsVectorLayer::splitParts ( const QList< QgsPoint > &  splitLine,
bool  topologicalEditing = false 
)

Splits parts cut by the given line.

Parameters
splitLineline that splits the layer features
topologicalEditingtrue if topological editing is enabled
Returns
0 in case of success, 4 if there is a selection but no feature split

Definition at line 1250 of file qgsvectorlayer.cpp.

§ startEditing

bool QgsVectorLayer::startEditing ( )
slot

Make layer editable.

This starts an edit session on this layer. Changes made in this edit session will not be made persistent until commitChanges() is called and can be reverted by calling rollBack().

Definition at line 1295 of file qgsvectorlayer.cpp.

§ storageType()

QString QgsVectorLayer::storageType ( ) const

Returns the permanent storage type for this layer as a friendly name.

Definition at line 193 of file qgsvectorlayer.cpp.

§ subsetString()

QString QgsVectorLayer::subsetString ( ) const
virtual

Get the string (typically sql) used to define a subset of the layer.

Returns
The subset string or QString::null if not implemented by the provider

Definition at line 896 of file qgsvectorlayer.cpp.

§ translateFeature()

int QgsVectorLayer::translateFeature ( QgsFeatureId  featureId,
double  dx,
double  dy 
)

Translates feature by dx, dy.

Parameters
featureIdid of the feature to translate
dxtranslation of x-coordinate
dytranslation of y-coordinate
Returns
0 in case of success

Definition at line 1237 of file qgsvectorlayer.cpp.

§ uniqueStringsMatching()

QStringList QgsVectorLayer::uniqueStringsMatching ( int  index,
const QString &  substring,
int  limit = -1,
QgsFeedback feedback = nullptr 
) const

Returns unique string values of an attribute which contain a specified subset string.

Subset matching is done in a case-insensitive manner. Note that in some circumstances when unsaved changes are present for the layer then the returned list may contain outdated values (for instance when the attribute value in a saved feature has been changed inside the edit buffer then the previous saved value will be included in the returned list).

Parameters
indexcolumn index for attribute
substringsubstring to match (case insensitive)
limitmaxmum number of the values to return, or -1 to return all unique values
feedbackoptional feedback object for cancelling request
Returns
list of unique strings containing substring

Definition at line 3227 of file qgsvectorlayer.cpp.

§ uniqueValues()

void QgsVectorLayer::uniqueValues ( int  index,
QList< QVariant > &  uniqueValues,
int  limit = -1 
) const

Calculates a list of unique values contained within an attribute in the layer.

Note that in some circumstances when unsaved changes are present for the layer then the returned list may contain outdated values (for instance when the attribute value in a saved feature has been changed inside the edit buffer then the previous saved value will be included in the returned list).

Parameters
indexcolumn index for attribute
uniqueValuesout: result list
limitmaximum number of values to return (or -1 if unlimited)
See also
minimumValue()
maximumValue()

Definition at line 3121 of file qgsvectorlayer.cpp.

§ updatedFields

void QgsVectorLayer::updatedFields ( )
signal

Is emitted, whenever the fields available from this layer have been changed.

This can be due to manually adding attributes or due to a join.

§ updateExpressionField()

void QgsVectorLayer::updateExpressionField ( int  index,
const QString &  exp 
)

Changes the expression used to define an expression based (virtual) field.

Parameters
indexThe index of the expression to change
expThe new expression to set
Note
added in 2.9

Definition at line 2933 of file qgsvectorlayer.cpp.

§ updateExtents

void QgsVectorLayer::updateExtents ( )
virtualslot

Update the extents for the layer.

This is necessary if features are added/deleted or the layer has been subsetted.

Definition at line 797 of file qgsvectorlayer.cpp.

§ updateFeature()

bool QgsVectorLayer::updateFeature ( QgsFeature f)

Updates an existing feature.

This method needs to query the datasource on every call. Consider using changeAttributeValue() or changeGeometry() instead.

Parameters
fFeature to update
Returns
True in case of success and False in case of error

Definition at line 969 of file qgsvectorlayer.cpp.

§ updateFields()

void QgsVectorLayer::updateFields ( )

Assembles mUpdatedFields considering provider fields, joined fields and added fields.

Definition at line 2939 of file qgsvectorlayer.cpp.

§ vectorJoins()

const QList< QgsVectorJoinInfo > QgsVectorLayer::vectorJoins ( ) const

Definition at line 2897 of file qgsvectorlayer.cpp.

§ wkbType()

QgsWkbTypes::Type QgsVectorLayer::wkbType ( ) const

Returns the WKBType or WKBUnknown in case of error.

Definition at line 534 of file qgsvectorlayer.cpp.

§ writeCustomSymbology

void QgsVectorLayer::writeCustomSymbology ( QDomElement &  element,
QDomDocument &  doc,
QString &  errorMessage 
) const
signal

Signal emitted whenever the symbology (QML-file) for this layer is being written.

If there is custom style information you want to save to the file, you can connect to this signal and update the element accordingly.

Parameters
elementThe XML element where you can add additional style information to.
docThe XML document that you can use to create new XML nodes.
errorMessageWrite error messages into this string.

§ writeSld()

bool QgsVectorLayer::writeSld ( QDomNode &  node,
QDomDocument &  doc,
QString &  errorMessage,
const QgsStringMap props = QgsStringMap() 
) const

Writes the symbology of the layer into the document provided in SLD 1.1 format.

Parameters
nodethe node that will have the style element added to it.
docthe document that will have the QDomNode added.
errorMessagereference to string that will be updated with any error messages
propsa open ended set of properties that can drive/inform the SLD encoding
Returns
true in case of success

Definition at line 2123 of file qgsvectorlayer.cpp.

§ writeStyle()

bool QgsVectorLayer::writeStyle ( QDomNode &  node,
QDomDocument &  doc,
QString &  errorMessage 
) const
overridevirtual

Write just the style information for the layer into the document.

Parameters
nodethe node that will have the style element added to it.
docthe document that will have the QDomNode added.
errorMessagereference to string that will be updated with any error messages
Returns
true in case of success.

Reimplemented from QgsMapLayer.

Definition at line 2042 of file qgsvectorlayer.cpp.

§ writeSymbology()

bool QgsVectorLayer::writeSymbology ( QDomNode &  node,
QDomDocument &  doc,
QString &  errorMessage 
) const
overridevirtual

Write the symbology for the layer into the docment provided.

Parameters
nodethe node that will have the style element added to it.
docthe document that will have the QDomNode added.
errorMessagereference to string that will be updated with any error messages
Returns
true in case of success.

Implements QgsMapLayer.

Definition at line 1956 of file qgsvectorlayer.cpp.

§ writeXml()

bool QgsVectorLayer::writeXml ( QDomNode &  layer_node,
QDomDocument &  doc 
) const
overridevirtual

Write vector layer specific state to project file Dom node.

Note
Called by QgsMapLayer::writeXml().

Reimplemented from QgsMapLayer.

Definition at line 1642 of file qgsvectorlayer.cpp.

Friends And Related Function Documentation

§ QgsVectorLayerEditBuffer

friend class QgsVectorLayerEditBuffer
friend

Definition at line 2062 of file qgsvectorlayer.h.

§ QgsVectorLayerFeatureSource

friend class QgsVectorLayerFeatureSource
friend

Definition at line 2094 of file qgsvectorlayer.h.

Property Documentation

§ displayExpression

QString QgsVectorLayer::displayExpression
readwrite

Definition at line 416 of file qgsvectorlayer.h.

§ editFormConfig

QgsEditFormConfig QgsVectorLayer::editFormConfig
readwrite

Definition at line 418 of file qgsvectorlayer.h.

§ mapTipTemplate

QString QgsVectorLayer::mapTipTemplate
readwrite

Definition at line 417 of file qgsvectorlayer.h.

§ readOnly

bool QgsVectorLayer::readOnly
readwrite

Definition at line 419 of file qgsvectorlayer.h.


The documentation for this class was generated from the following files: