QgsVectorLayer Class Reference

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

#include <qgsvectorlayer.h>

Inheritance diagram for QgsVectorLayer:

Classes
struct	GroupData
struct	RangeData
struct	TabData
struct	ValueRelationData

Public Types
enum	EditorLayout { GeneratedLayout = 0, TabLayout = 1, UiFileLayout = 2 }
	The different types to layout the attribute editor. More...
enum	EditType {   LineEdit, UniqueValues, UniqueValuesEditable, ValueMap,   Classification, EditRange, SliderRange, CheckBox,   FileName, Enumeration, Immutable, Hidden,   TextEdit, Calendar, DialRange, ValueRelation,   UuidGenerator, Photo, WebView, Color,   EditorWidgetV2 }
enum	FeatureFormSuppress { SuppressDefault = 0, SuppressOn = 1, SuppressOff = 2 }
	Types of feature form suppression after feature creation. More...
enum	VertexMarkerType { SemiTransparentCircle, Cross, NoMarker }
	Editing vertex markers. More...
Public Types inherited from QgsMapLayer
enum	LayerType { VectorLayer, RasterLayer, PluginLayer }
	Layers enum defining the types of layers that can be added to a map. More...

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

Signals
void	attributeAdded (int idx)
	Will be emitted, when a new attribute has been added to this vector layer.
void	attributeDeleted (int idx)
	Will be emitted, when an attribute has been deleted from this vector layer.
void	attributeValueChanged (QgsFeatureId fid, int idx, const QVariant &)
void	beforeCommitChanges ()
	Is emitted, before changes are commited to the data provider.
void	beforeModifiedCheck () const
	Is emitted, when layer is checked for modifications.
void	beforeRollBack ()
	Is emitted, before changes are rolled back.
void	committedAttributesAdded (const QString &layerId, const QList< QgsField > &addedAttributes)
void	committedAttributesDeleted (const QString &layerId, const QgsAttributeList &deletedAttributes)
	Signals emitted after committing changes.
void	committedAttributeValuesChanges (const QString &layerId, const QgsChangedAttributesMap &changedAttributesValues)
void	committedFeaturesAdded (const QString &layerId, const QgsFeatureList &addedFeatures)
void	committedFeaturesRemoved (const QString &layerId, const QgsFeatureIds &deletedFeatureIds)
void	committedGeometriesChanges (const QString &layerId, const QgsGeometryMap &changedGeometries)
void	editCommandDestroyed ()
	Signal emitted, whan an edit command is destroyed.
void	editCommandEnded ()
	Signal emitted, when an edit command successfully ended.
void	editCommandStarted (const QString &text)
	Signal emitted when a new edit command has been started.
void	editingStarted ()
	Is emitted, when editing on this layer has started.
void	editingStopped ()
	Is emitted, when edited changes successfully have been written to the data provider.
void	featureAdded (QgsFeatureId fid)
void	featureBlendModeChanged (const QPainter::CompositionMode &blendMode)
	Signal emitted when setFeatureBlendMode() is called.
void	featureDeleted (QgsFeatureId fid)
void	geometryChanged (QgsFeatureId fid, QgsGeometry &geom)
void	labelingFontNotFound (QgsVectorLayer *layer, const QString &fontfamily)
	Emitted when the font family defined for labeling layer is not found on system.
void	layerDeleted ()
void	layerModified ()
	This signal is emitted when modifications has been done on layer.
void	layerTransparencyChanged (int layerTransparency)
	Signal emitted when setLayerTransparency() is called.
void	readCustomSymbology (const QDomElement &element, QString &errorMessage)
	Signal emitted whenever the symbology (QML-file) for this layer is being read.
void	saveLayerToProject ()
void	selectionChanged (const QgsFeatureIds selected, const QgsFeatureIds deselected, const bool clearAndSelect)
	This signal is emitted when selection was changed.
void	selectionChanged ()
	This signal is emitted when selection was changed.
void	updatedFields ()
	Is emitted, whenever the fields available from this layer have been changed.
void	writeCustomSymbology (QDomElement &element, QDomDocument &doc, QString &errorMessage) const
	Signal emitted whenever the symbology (QML-file) for this layer is being written.
Signals inherited from QgsMapLayer
void	blendModeChanged (const QPainter::CompositionMode &blendMode)
	Signal emitted when the blend mode is changed, through QgsMapLayer::setBlendMode()
void	dataChanged ()
	data of layer changed
void	drawingProgress (int theProgress, int theTotalSteps)
void	layerCrsChanged ()
	Emit a signal that layer's CRS has been reset.
void	layerNameChanged ()
	Emit a signal that the layer name has been changed.
void	legendChanged ()
	Signal emitted when legend of the layer has changed.
void	recalculateExtents ()
	This is used to send a request that any mapcanvas using this layer update its extents.
void	rendererChanged ()
	Signal emitted when renderer is changed.
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.
void	screenUpdateRequested ()
void	statusChanged (QString theStatus)
	Emit a signal with status (e.g.

Public Member Functions
	QgsVectorLayer (QString path=QString::null, QString baseName=QString::null, QString providerLib=QString::null, bool loadDefaultStyleFlag=true)
	Constructor - creates a vector layer.
virtual	~QgsVectorLayer ()
	Destructor.
QgsAttributeAction *	actions ()
bool	addAttribute (const QgsField &field)
	add an attribute field (but does not commit it) returns true if the field was added
void	addAttributeAlias (int attIndex, QString aliasString)
	Sets an alias (a display name) for attributes to display in dialogs.
void	addAttributeEditorWidget (QgsAttributeEditorElement *data)
	Adds a tab (for the attribute editor form) holding groups and fields.
void	addExpressionField (const QString &exp, const QgsField &fld)
	Add a new field which is calculated by the expression specified.
bool	addFeature (QgsFeature &f, bool alsoUpdateExtent=true)
	Adds a feature.
bool	addFeatures (QgsFeatureList features, bool makeSelected=true)
	Insert a copy of the given features into the layer (but does not commit it)
bool	addJoin (const QgsVectorJoinInfo &joinInfo)
	Joins another vector layer to this layer.
int	addPart (const QList< QgsPoint > &ring)
	Adds a new part polygon to a multipart feature.
int	addRing (const QList< QgsPoint > &ring)
	Adds a ring to polygon/multipolygon features.
int	addTopologicalPoints (QgsGeometry *geom)
	Adds topological points for every vertex of the geometry.
int	addTopologicalPoints (const QgsPoint &p)
	Adds a vertex to segments which intersect point p but don't already have a vertex there.
QgsFeatureIds	allFeatureIds ()
	Get all feature Ids.
QString	annotationForm () const
	get annotation form
virtual bool	applyNamedStyle (QString namedStyle, QString &errorMsg)
	Will load a named style from a provided QML string.
QString	attributeAlias (int attributeIndex) const
	Returns the alias of an attribute name or an empty string if there is no alias.
const QMap< QString, QString > &	attributeAliases () const
QString	attributeDisplayName (int attributeIndex) const
	Convenience function that returns the attribute alias if defined or the field name else.
QgsAttributeEditorElement *	attributeEditorElementFromDomElement (QDomElement &elem, QObject *parent)
	convert a saved attribute editor element into a AttributeEditor structure as it's used internally.
QList < QgsAttributeEditorElement * > &	attributeEditorElements ()
	Returns a list of tabs holding groups and fields.
void	beginEditCommand (QString text)
	Create edit command for undo/redo operations.
QgsRectangle	boundingBoxOfSelected ()
	Returns the bounding box of the selected features.
QgsGeometryCache *	cache ()
QString	capabilitiesString () const
	Capabilities for this layer in a friendly format.
Q_DECL_DEPRECATED bool	changeAttributeValue (QgsFeatureId fid, int field, QVariant value, bool emitSignal)
	Changes an attribute value (but does not commit it)
bool	changeAttributeValue (QgsFeatureId fid, int field, const QVariant &newValue, const QVariant &oldValue=QVariant())
	Changes an attribute value (but does not commit it)
bool	changeGeometry (QgsFeatureId fid, QgsGeometry *geom)
	change feature's geometry
void	clearAttributeEditorWidgets ()
	Clears all the tabs for the attribute editor form.
bool	commitChanges ()
	Attempts to commit any changes to disk.
const QStringList &	commitErrors ()
bool	countSymbolFeatures (bool showProgress=true)
	Count features for symbols.
void	createJoinCaches ()
	Caches joined attributes if required (and not already done)
virtual QgsMapLayerRenderer *	createMapRenderer (QgsRenderContext &rendererContext) override
	Return new instance of QgsMapLayerRenderer that will be used for rendering of given context.
QString	dataComment () const
	Returns a comment for the data in the layer.
QgsVectorDataProvider *	dataProvider ()
	Returns the data provider.
const QgsVectorDataProvider *	dataProvider () const
	Returns the data provider in a const-correct manner.
Q_DECL_DEPRECATED QString	dateFormat (int idx)
	Access date format.
bool	deleteAttribute (int attr)
	delete an attribute field (but does not commit it)
bool	deleteAttributes (QList< int > attrs)
	Deletes a list of attribute fields (but does not commit it)
bool	deleteFeature (QgsFeatureId fid)
	delete a feature from the layer (but does not commit it)
bool	deleteSelectedFeatures (int *deletedCount=0)
	Deletes the selected features.
bool	deleteVertex (QgsFeatureId atFeatureId, int atVertex)
	Deletes a vertex from a feature.
void	destroyEditCommand ()
	Destroy active command and reverts all changes in it.
const QgsDiagramLayerSettings *	diagramLayerSettings () const
const QgsDiagramRendererV2 *	diagramRenderer () const
const QString	displayExpression ()
	Get the preview expression, used to create a human readable preview string.
const QString	displayField () const
	Returns the primary display field name used in the identify results dialog.
bool	draw (QgsRenderContext &rendererContext) override
	Draws the layer.
void	drawLabels (QgsRenderContext &rendererContext) override
	Draws the layer labels using coordinate transformation.
QgsVectorLayerEditBuffer *	editBuffer ()
	Buffer with uncommitted editing operations. Only valid after editing has been turned on.
QString	editForm ()
	get edit form
QString	editFormInit ()
	get python function for edit form initialization
EditorLayout	editorLayout ()
	get the active layout for the attribute editor for this layer
const QString	editorWidgetV2 (int fieldIdx) const
	Get the id for the editor widget used to represent the field at the given index.
const QString	editorWidgetV2 (const QString &fieldName) const
	Get the id for the editor widget used to represent the field at the given index.
const QgsEditorWidgetConfig	editorWidgetV2Config (int fieldIdx) const
	Get the configuration for the editor widget used to represent the field at the given index.
const QgsEditorWidgetConfig	editorWidgetV2Config (const QString &fieldName) const
	Get the configuration for the editor widget used to represent the field at the given index.
Q_DECL_DEPRECATED EditType	editType (int idx)
	Get edit type.
void	enableLabels (bool on)
	Set labels on.
void	endEditCommand ()
	Finish edit command and add it to undo/redo stack.
const QSet< QString > &	excludeAttributesWFS () const
const QSet< QString > &	excludeAttributesWMS () const
QgsRectangle	extent () override
	Return the extent of the layer as a QRect.
QPainter::CompositionMode	featureBlendMode () const
	Read blend mode for layer.
virtual long	featureCount () const
	Number of features in the layer.
long	featureCount (QgsSymbolV2 *symbol)
	Number of features rendered with specified symbol.
QgsVectorLayer::FeatureFormSuppress	featureFormSuppress () const
	Type of feature form pop-up suppression after feature creation (overrides app setting)
bool	fieldEditable (int idx)
	is edit widget editable
int	fieldNameIndex (const QString &fieldName) const
	Returns the index of a field name or -1 if the field does not exist.
QGis::GeometryType	geometryType () const
	Returns point, line or polygon.
QgsFeatureIterator	getFeatures (const QgsFeatureRequest &request=QgsFeatureRequest())
	Query the provider for features specified in request.
virtual QString	getStyleFromDatabase (QString styleId, QString &msgError)
	Will return the named style corresponding to style id provided.
bool	hasGeometryType () const
	Returns true if this is a geometry layer and false in case of NoGeometry (table only) or UnknownGeometry.
bool	hasLabelsEnabled () const
	Label is on.
int	insertSegmentVerticesForSnap (const QList< QgsSnappingResult > &snapResults)
	Inserts vertices to the snapped segments.
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.
void	invertSelection ()
	Select not selected features and deselect selected ones.
void	invertSelectionInRectangle (QgsRectangle &rect)
	Invert selection of features found within the search rectangle (in layer's coordinates)
virtual bool	isEditable () const override
	Returns true if the provider is in editing mode.
virtual bool	isModified () const
	Returns true if the provider has been modified since the last commit.
virtual bool	isReadOnly () const
	Returns true if the provider is in read-only mode.
QgsLabel *	label ()
	Get the label object associated with this layer.
const QgsLabel *	label () const
bool	labelOnTop (int idx)
	label widget on top
int	layerTransparency () const
	Read transparency for layer.
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.
virtual QString	loadNamedStyle (const QString &theURI, bool &theResultFlag, bool loadFromLocalDb)
	Load a named style from file/local db/datasource db.
virtual QString	loadNamedStyle (const QString &theURI, bool &theResultFlag) override
	Calls loadNamedStyle( theURI, theResultFlag, false ); Retained for backward compatibility.
QVariant	maximumValue (int index)
	Returns maximum value for an attribute column or invalid variant in case of error.
QString	metadata () override
	Obtain Metadata for this layer.
QVariant	minimumValue (int index)
	Returns minimum value for an attribute column or invalid variant in case of error.
void	modifySelection (QgsFeatureIds selectIds, QgsFeatureIds deselectIds)
	Modifies the current selection on this layer.
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.
QgsAttributeList	pendingAllAttributesList ()
	returns list of attributes
int	pendingFeatureCount ()
	returns feature count after commit
const QgsFields &	pendingFields () const
	returns field list in the to-be-committed state
QgsAttributeList	pendingPkAttributesList ()
	returns list of attribute making up the primary key
QString	providerType () const
	Return the provider type for this layer.
Q_DECL_DEPRECATED RangeData	range (int idx)
	Access range widget config data.
bool	readSld (const QDomNode &node, QString &errorMessage) override
bool	readSymbology (const QDomNode &node, QString &errorMessage) override
	Read the symbology for the current layer from the Dom node supplied.
virtual bool	readXml (const QDomNode &layer_node) override
	reads vector layer specific state from project file Dom node.
QList< QgsRelation >	referencingRelations (int idx)
	Get relations, where the foreign key is on this layer.
virtual void	reload () override
	Synchronises with changes in the datasource.
void	remAttributeAlias (int attIndex)
	Removes an alias (a display name) for attributes to display in dialogs.
void	removeExpressionField (int index)
	Remove an expression field.
void	removeJoin (const QString &joinLayerId)
	Removes a vector layer join.
Q_DECL_DEPRECATED int	removePolygonIntersections (QgsGeometry *geom, QgsFeatureIds ignoreFeatures=QgsFeatureIds())
	Changes the specified geometry such that it has no intersections with other polygon (or multipolygon) geometries in this vector layer.
QgsFeatureRendererV2 *	rendererV2 ()
	Return renderer V2.
bool	rollBack (bool deleteBuffer=true)
	Stop editing and discard the edits.
virtual void	saveStyleToDatabase (QString name, QString description, bool useAsDefault, QString uiFileContent, QString &msgError)
	Save named and sld style of the layer to the style table in the db.
void	select (QgsRectangle &rect, bool addToSelection)
	Select features found within the search rectangle (in layer's coordinates)
void	selectAll ()
	Select all the features.
int	selectedFeatureCount ()
	The number of features that are selected in this layer.
QgsFeatureList	selectedFeatures ()
	Get a copy of the user-selected features.
const QgsFeatureIds &	selectedFeaturesIds () const
	Return reference to identifiers of selected features.
QgsFeatureIterator	selectedFeaturesIterator (QgsFeatureRequest request=QgsFeatureRequest())
	Get an iterator of the selected features.
void	setAnnotationForm (const QString &ui)
	set annotation form for layer
Q_DECL_DEPRECATED void	setCheckedState (int idx, QString checked, QString notChecked)
	Set string representing 'true' for a checkbox.
void	setCoordinateSystem ()
	Setup the coordinate system transformation for the layer.
void	setDiagramLayerSettings (const QgsDiagramLayerSettings &s)
void	setDiagramRenderer (QgsDiagramRendererV2 *r)
	Sets diagram rendering object (takes ownership)
void	setDisplayExpression (const QString &displayExpression)
	Set the preview expression, used to create a human readable preview string.
void	setDisplayField (QString fldName="")
	Set the primary display field to be used in the identify results dialog.
void	setEditForm (QString ui)
	set edit form
void	setEditFormInit (QString function)
	set python function for edit form initialization
void	setEditorLayout (EditorLayout editorLayout)
	set the active layout for the attribute editor for this layer
void	setEditorWidgetV2 (int attrIdx, const QString &widgetType)
	Set the editor widget type for a field.
void	setEditorWidgetV2Config (int attrIdx, const QgsEditorWidgetConfig &config)
	Set the editor widget config for a field.
Q_DECL_DEPRECATED void	setEditType (int idx, EditType edit)
	Get edit type.
void	setExcludeAttributesWFS (const QSet< QString > &att)
void	setExcludeAttributesWMS (const QSet< QString > &att)
void	setFeatureBlendMode (const QPainter::CompositionMode &blendMode)
	Write blend mode for features.
void	setFeatureFormSuppress (QgsVectorLayer::FeatureFormSuppress s)
	Set type of feature form pop-up suppression after feature creation (overrides app setting)
void	setFieldEditable (int idx, bool editable)
	set edit widget editable
void	setLabelOnTop (int idx, bool onTop)
	label widget on top
void	setLayerTransparency (int layerTransparency)
	Write transparency for layer.
void	setProviderEncoding (const QString &encoding)
	Sets the textencoding of the data provider.
bool	setReadOnly (bool readonly=true)
	Make layer read-only (editing disabled) or not.
void	setRendererV2 (QgsFeatureRendererV2 *r)
	Set renderer V2.
void	setSelectedFeatures (const QgsFeatureIds &ids)
	Change selection to the new set of features.
void	setSimplifyMethod (const QgsVectorSimplifyMethod &simplifyMethod)
	Set the simplification settings for fast rendering of features.
virtual bool	setSubsetString (QString subset)
	Set the string (typically sql) used to define a subset of the layer.
bool	simplifyDrawingCanbeApplied (const QgsRenderContext &renderContext, QgsVectorSimplifyMethod::SimplifyHint simplifyHint) const
	Returns whether the VectorLayer can apply the specified simplification hint.
const QgsVectorSimplifyMethod &	simplifyMethod () const
	Returns the simplification settings for fast rendering of features.
bool	snapPoint (QgsPoint &point, double tolerance)
	Snaps a point to the closest vertex if there is one within the snapping tolerance.
int	snapWithContext (const QgsPoint &startPoint, double snappingTolerance, QMultiMap< double, QgsSnappingResult > &snappingResults, QgsSnapper::SnappingType snap_to)
	Snaps to segment or vertex within given tolerance.
int	splitFeatures (const QList< QgsPoint > &splitLine, bool topologicalEditing=false)
	Splits features cut by the given line.
int	splitParts (const QList< QgsPoint > &splitLine, bool topologicalEditing=false)
	Splits parts cut by the given line.
bool	startEditing ()
	Make layer editable.
QString	storageType () const
	Returns the permanent storage type for this layer as a friendly name.
virtual QString	subsetString ()
	Get the string (typically sql) used to define a subset of the layer.
int	translateFeature (QgsFeatureId featureId, double dx, double dy)
	Translates feature by dx, dy.
void	uniqueValues (int index, QList< QVariant > &uniqueValues, int limit=-1)
	Returns unique values for column.
bool	updateFeature (QgsFeature &f)
	Updates an existing feature.
void	updateFields ()
	Assembles mUpdatedFields considering provider fields, joined fields and added fields.
Q_DECL_DEPRECATED QMap < QString, QVariant >	valueMap (int idx)
	Access value map.
ValueRelationData	valueRelation (int idx)
	Access value relation widget data.
const QList< QgsVectorJoinInfo > &	vectorJoins () const
Q_DECL_DEPRECATED QSize	widgetSize (int idx)
	Access widget size for photo and webview widget.
QGis::WkbType	wkbType () const
	Returns the WKBType or WKBUnknown in case of error.
bool	writeSld (QDomNode &node, QDomDocument &doc, QString &errorMessage) const
bool	writeSymbology (QDomNode &node, QDomDocument &doc, QString &errorMessage) const override
	Write the symbology for the layer into the docment provided.
virtual bool	writeXml (QDomNode &layer_node, QDomDocument &doc) override
	write vector layer specific state to project file Dom node.
Public Member Functions inherited from QgsMapLayer
	QgsMapLayer (QgsMapLayer::LayerType type=VectorLayer, QString lyrname=QString::null, QString source=QString::null)
	Constructor.
virtual	~QgsMapLayer ()
	Destructor.
const QString &	abstract () const
const QString &	attribution () const
const QString &	attributionUrl () const
QPainter::CompositionMode	blendMode () const
	Read blend mode for layer.
Q_DECL_DEPRECATED QImage *	cacheImage ()
const QgsCoordinateReferenceSystem &	crs () const
	Returns layer's spatial reference system.
QVariant	customProperty (const QString &value, const QVariant &defaultValue=QVariant()) const
	Read a custom property from layer.
const QString &	dataUrl () const
const QString &	dataUrlFormat () const
virtual QgsError	error () const
	Get current status error.
virtual void	exportNamedStyle (QDomDocument &doc, QString &errorMsg)
	Export the properties of this layer as named style in a QDomDocument.
virtual void	exportSldStyle (QDomDocument &doc, QString &errorMsg)
	Export the properties of this layer as SLD style in a QDomDocument.
bool	hasScaleBasedVisibility () const
	Returns whether scale based visibility is enabled for the layer.
QString	id () const
	Get this layer's unique ID, this ID is used to access this layer from map layer registry.
virtual bool	importNamedStyle (QDomDocument &doc, QString &errorMsg)
	Import the properties of this layer from a QDomDocument.
bool	isValid ()
const QString &	keywordList () const
virtual Q_DECL_DEPRECATED QString	lastError ()
virtual Q_DECL_DEPRECATED QString	lastErrorTitle ()
QgsMapLayerLegend *	legend () const
	Can be null.
const QString &	legendUrl () const
const QString &	legendUrlFormat () const
virtual QString	loadDefaultStyle (bool &theResultFlag)
	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)
virtual bool	loadNamedStyleFromDb (const QString &db, const QString &theURI, QString &qml)
virtual QString	loadSldStyle (const QString &theURI, bool &theResultFlag)
float	maximumScale () const
	Returns the maximum scale denominator at which the layer is visible.
const QString &	metadataUrl () const
const QString &	metadataUrlFormat () const
const QString &	metadataUrlType () const
float	minimumScale () const
	Returns the minimum scale denominator at which the layer is visible.
const QString &	name () const
	Get the display name of the layer.
virtual Q_DECL_DEPRECATED void	onCacheImageDelete ()
const QString &	originalName () const
	Get the original name of the layer.
QString	publicSource () const
bool	readLayerXML (const QDomElement &layerElement)
	sets state from Dom document
void	removeCustomProperty (const QString &key)
	Remove a custom property from layer.
virtual QString	saveDefaultStyle (bool &theResultFlag)
	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)
virtual QString	saveNamedStyle (const QString &theURI, bool &theResultFlag)
	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)
virtual QString	saveSldStyle (const QString &theURI, bool &theResultFlag)
void	setAbstract (const QString &abstract)
void	setAttribution (const QString &attrib)
void	setAttributionUrl (const QString &attribUrl)
void	setBlendMode (const QPainter::CompositionMode &blendMode)
	Write blend mode for layer.
Q_DECL_DEPRECATED void	setCacheImage (QImage *)
void	setCrs (const QgsCoordinateReferenceSystem &srs, bool emitSignal=true)
	Sets layer's spatial reference system.
void	setCustomProperty (const QString &key, const QVariant &value)
	Set a custom property for layer.
void	setDataUrl (const QString &dataUrl)
void	setDataUrlFormat (const QString &dataUrlFormat)
void	setKeywordList (const QString &keywords)
void	setLayerName (const QString &name)
	Set the display name of the layer.
virtual void	setLayerOrder (const QStringList &layers)
	Reorders the previously selected sublayers of this layer from bottom to top (Useful for providers that manage their own layers, such as WMS)
void	setLegend (QgsMapLayerLegend *legend)
	Assign a legend controller to the map layer.
void	setLegendUrl (const QString &legendUrl)
void	setLegendUrlFormat (const QString &legendUrlFormat)
void	setMetadataUrl (const QString &metaUrl)
void	setMetadataUrlFormat (const QString &metaUrlFormat)
void	setMetadataUrlType (const QString &metaUrlType)
virtual void	setSubLayerVisibility (QString name, bool vis)
	Set the visibility of the given sublayer name.
void	setTitle (const QString &title)
const QString &	source () const
	Returns the source for the layer.
QgsMapLayerStyleManager *	styleManager () const
	Get access to the layer's style manager.
virtual QString	styleURI ()
	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)
virtual QStringList	subLayers () const
	Returns the sublayers of this layer (Useful for providers that manage their own layers, such as WMS)
const QString &	title () const
QgsMapLayer::LayerType	type () const
	Get the type of the layer.
QUndoStack *	undoStack ()
	Return pointer to layer's undo stack.
bool	writeLayerXML (QDomElement &layerElement, QDomDocument &document, QString relativeBasePath=QString::null)
	stores state in Dom node

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.
Static Public Member Functions inherited from QgsMapLayer
static QDomDocument	asLayerDefinition (QList< QgsMapLayer * > layers, 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.
static QString	capitaliseLayerName (const QString &name)
	A convenience function to (un)capitalise the layer name.
static QList< QgsMapLayer * >	fromLayerDefinition (QDomDocument &document)
	Creates a new layer from a layer defininition document.
static QList< QgsMapLayer * >	fromLayerDefinitionFile (const QString &qlrfile)

Protected Slots
void	invalidateSymbolCountedFlag ()

Protected Member Functions
void	setExtent (const QgsRectangle &rect) override
	Set the extent.
Protected Member Functions inherited from QgsMapLayer
void	appendError (const QgsErrorMessage &theMessage)
	Add error message.
void	readCustomProperties (const QDomNode &layerNode, const QString &keyStartsWith="")
	Read custom properties from project file.
void	readStyleManager (const QDomNode &layerNode)
	Read style manager's configuration (if any).
void	setError (const QgsError &theError)
	Set error message.
void	setValid (bool valid)
	set whether layer is valid or not - should be used in constructor.
void	writeCustomProperties (QDomNode &layerNode, QDomDocument &doc) const
	Write custom properties to project file.
void	writeStyleManager (QDomNode &layerNode, QDomDocument &doc) const
	Write style manager's configuration (if exists).

Friends
class	QgsVectorLayerEditBuffer
class	QgsVectorLayerFeatureSource

Additional Inherited Members
Protected Attributes inherited from QgsMapLayer
QString	mAbstract
	Description of the layer.
QString	mAttribution
	Attribution of the layer.
QString	mAttributionUrl
QString	mDataSource
	data source description string, varies by layer type
QString	mDataUrl
	DataUrl of the layer.
QString	mDataUrlFormat
QgsError	mError
	Error.
QgsRectangle	mExtent
	Extent of the layer.
QString	mKeywordList
QString	mLayerName
	Name of the layer - used for display.
QString	mLayerOrigName
	Original name of the layer.
QString	mLegendUrl
	WMS legend.
QString	mLegendUrlFormat
QString	mMetadataUrl
	MetadataUrl of the layer.
QString	mMetadataUrlFormat
QString	mMetadataUrlType
QString	mTitle
bool	mValid
	Indicates if the layer is valid and can be drawn.

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:

• crs=definition Defines the coordinate reference system to use for the layer. definition is any string accepted by QgsCoordinateReferenceSystem::createFromString()

• index=yes Specifies that the layer will be constructed with a spatial index

• field=name:type(length,precision) Defines an attribute of the layer. Multiple field parameters can be added to the data provider definition. type is one of "integer", "double", "string".

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 1.0.0 server or a GML2 data file path. Examples are http://foobar/wfs or /foo/bar/file.gml

If a GML2 file path is provided the driver will attempt to read the schema from a file in the same directory with the same basename + “.xsd”. This xsd file must be in the same format as a WFS describe feature type response. If no xsd file is provide then the driver will attempt to guess the attribute types from the file.

In the case of a HTTP URL 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:

• You can use various functions available in the QGIS Expression list, however the function must exist server side and have the same name and arguments to work.

• Use the special $geometry parameter to provide the layer geometry column as input into the spatial binary operators e.g intersects($geometry, geomFromWKT('POINT (5 6)'))

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:

• encoding=UTF-8

  Defines the character encoding in the file. The default is UTF-8. To use the default encoding for the operating system use "System".

• type=(csv|regexp|whitespace|plain)

  Defines the algorithm used to split records into columns. Records are defined by new lines, except for csv format files for which quoted fields may span multiple records. The default type is csv.

  • "csv" splits the file based on three sets of characters: delimiter characters, quote characters, and escape characters. Delimiter characters mark the end of a field. Quote characters enclose a field which can contain delimiter characters, and newlines. Escape characters cause the following character to be treated literally (including delimiter, quote, and newline characters). Escape and quote characters must be different from delimiter characters. Escape characters that are also quote characters are treated specially - they can only escape themselves within quotes. Elsewhere they are treated as quote characters. The defaults for delimiter, quote, and escape are ',', '"', '"'.
  • "regexp" splits each record using a regular expression (see QRegExp documentation for details).
  • "whitespace" splits each record based on whitespace (on or more whitespace characters. Leading whitespace in the record is ignored.
  • "plain" is provided for backwards compatibility. It is equivalent to CSV except that the default quote characters are single and double quotes, and there is no escape characters.

• delimiter=characters

  Defines the delimiter characters used for csv and plain type files, or the regular expression for regexp type files. It is a literal string of characters except that "\t" may be used to represent a tab character.

• quote=characters

  Defines the characters that are used as quote characters for csv and plain type files.

• escape=characters

  Defines the characters used to escape delimiter, quote, and newline characters.

• skipLines=n

  Defines the number of lines to ignore at the beginning of the file (default 0)

• useHeader=(yes|no)

  Defines whether the first record in the file (after skipped lines) contains column names (default yes)

• trimFields=(yes|no)

  If yes then leading and trailing whitespace will be removed from fields

• skipEmptyFields=(yes|no)

  If yes then empty fields will be discarded (eqivalent to concatenating consecutive delimiters)

• maxFields=#

  Specifies the maximum number of fields to load for each record. Additional fields will be discarded. Default is 0 - load all fields.

• decimalPoint=c

  Defines a character that is used as a decimal point in the numeric columns The default is '.'.

• xField=column yField=column

  Defines the name of the columns holding the x and y coordinates for XY point geometries. If the useHeader is no (ie there are no column names), then this is the column number (with the first column as 1).

• xyDms=(yes|no)

  If yes then the X and Y coordinates are interpreted as degrees/minutes/seconds format (fairly permissively), or degree/minutes format.

• wktField=column

  Defines the name of the columns holding the WKT geometry definition for WKT geometries. If the useHeader is no (ie there are no column names), then this is the column number (with the first column as 1).

• geomType=(point|line|polygon|none)

  Defines the geometry type for WKT type geometries. QGIS will only display one type of geometry for the layer - any others will be ignored when the file is loaded. By default the provider uses the type of the first geometry in the file. Use geomType to override this type.

  geomType can also be set to none, in which case the layer is loaded without geometries.

• subset=expression

  Defines an expression that will identify a subset of records to display

• crs=crsstring

  Defines the coordinate reference system used for the layer. This can be any string accepted by QgsCoordinateReferenceSystem::createFromString()

-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.

• quiet

  Errors encountered loading the file will not be reported in a user dialog if quiet is included (They will still be shown in the output log).

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.

Definition at line 474 of file qgsvectorlayer.h.

Member Enumeration Documentation

enum QgsVectorLayer::EditorLayout

The different types to layout the attribute editor.

Enumerator:

GeneratedLayout
TabLayout
UiFileLayout

Definition at line 480 of file qgsvectorlayer.h.

enum QgsVectorLayer::EditType

Deprecated:

Use the editorWidgetV2() system instead

Enumerator:

LineEdit
UniqueValues
UniqueValuesEditable
ValueMap
Classification
EditRange
SliderRange
CheckBox
FileName
Enumeration
Immutable	The attribute value should not be changed in the attribute form.
Hidden	The attribute value should not be shown in the attribute form.
TextEdit	multiline edit
Calendar	calendar widget
DialRange	dial range
ValueRelation	value map from an table
UuidGenerator	uuid generator - readonly and automatically intialized
Photo	phote widget
WebView	webview widget
Color	color
EditorWidgetV2	modularized edit widgets Note added in 2.1

Definition at line 490 of file qgsvectorlayer.h.

enum QgsVectorLayer::FeatureFormSuppress

Types of feature form suppression after feature creation.

Note

added in 2.1

Enumerator:

SuppressDefault
SuppressOn
SuppressOff

Definition at line 517 of file qgsvectorlayer.h.

enum QgsVectorLayer::VertexMarkerType

Editing vertex markers.

Enumerator:

SemiTransparentCircle
Cross
NoMarker

Definition at line 1427 of file qgsvectorlayer.h.

Constructor & Destructor Documentation

QgsVectorLayer::QgsVectorLayer	(	QString	path = QString::null,
		QString	baseName = QString::null,
		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

path	The path or url of the parameter. Typically this encodes parameters used by the data provider as url query items.
baseName	The name used to represent the layer in the legend
providerLib	The name of the data provider, eg "memory", "postgres"
loadDefaultStyleFlag	whether to load the default style

Definition at line 121 of file qgsvectorlayer.cpp.

QgsVectorLayer::~QgsVectorLayer ( )

virtual

Destructor.

Definition at line 195 of file qgsvectorlayer.cpp.

Member Function Documentation

QgsAttributeAction* QgsVectorLayer::actions ( )

inline

Definition at line 676 of file qgsvectorlayer.h.

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 2066 of file qgsvectorlayer.cpp.

void QgsVectorLayer::addAttributeAlias	(	int	attIndex,
		QString	aliasString
	)

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

Definition at line 2087 of file qgsvectorlayer.cpp.

void QgsVectorLayer::addAttributeEditorWidget

(

QgsAttributeEditorElement *

data

)

Adds a tab (for the attribute editor form) holding groups and fields.

Definition at line 2098 of file qgsvectorlayer.cpp.

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

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

Parameters

exp	The expression which calculates the field
fld	The field to calculate

Note

added in 2.6

Definition at line 2846 of file qgsvectorlayer.cpp.

bool QgsVectorLayer::addFeature	(	QgsFeature &	f,
		bool	alsoUpdateExtent = true
	)

Adds a feature.

Parameters

f	feature to add
alsoUpdateExtent	If 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 948 of file qgsvectorlayer.cpp.

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 2382 of file qgsvectorlayer.cpp.

bool QgsVectorLayer::addJoin

(

const QgsVectorJoinInfo &

joinInfo

)

Joins another vector layer to this layer.

Parameters

joinInfo

join 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 2826 of file qgsvectorlayer.cpp.

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 1077 of file qgsvectorlayer.cpp.

int QgsVectorLayer::addRing

(

const QList< QgsPoint > &

ring

)

Adds a ring to polygon/multipolygon features.

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 1068 of file qgsvectorlayer.cpp.

int QgsVectorLayer::addTopologicalPoints

(

QgsGeometry *

geom

)

Adds topological points for every vertex of the geometry.

Parameters

geom	the 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 1171 of file qgsvectorlayer.cpp.

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

p	position of the vertex

Returns

0 in case of success

Definition at line 1180 of file qgsvectorlayer.cpp.

QgsFeatureIds QgsVectorLayer::allFeatureIds

(

)

Get all feature Ids.

Definition at line 513 of file qgsvectorlayer.cpp.

QString QgsVectorLayer::annotationForm ( ) const

inline

get annotation form

Definition at line 1347 of file qgsvectorlayer.h.

bool QgsVectorLayer::applyNamedStyle ( QString  namedStyle, QString &  errorMsg  )

virtual

Will load a named style from a provided QML string.

Parameters

namedStyle	A QML string
errorMsg	An error message indicating problems if any

Returns

true on success

Deprecated:

Will be removed for QGIS 3 in favor of importNamedStyle

Definition at line 3867 of file qgsvectorlayer.cpp.

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 and QgsFields::OriginProvider

Parameters

idx	The index of the new attribute

See Also

updatedFields()

QString QgsVectorLayer::attributeAlias

(

int

attributeIndex

)

const

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

Definition at line 2126 of file qgsvectorlayer.cpp.

const QMap< QString, QString >& QgsVectorLayer::attributeAliases ( ) const

inline

Definition at line 1209 of file qgsvectorlayer.h.

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 and QgsFields::OriginProvider

Parameters

idx	The index of the deleted attribute

See Also

updatedFields()

QString QgsVectorLayer::attributeDisplayName

(

int

attributeIndex

)

const

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

Definition at line 2136 of file qgsvectorlayer.cpp.

QgsAttributeEditorElement * QgsVectorLayer::attributeEditorElementFromDomElement	(	QDomElement &	elem,
		QObject *	parent
	)

convert a saved attribute editor element into a AttributeEditor structure as it's used internally.

Parameters

elem	the DOM element
parent	the QObject which will own this object

Definition at line 1759 of file qgsvectorlayer.cpp.

QList< QgsAttributeEditorElement * > & QgsVectorLayer::attributeEditorElements

(

)

Returns a list of tabs holding groups and fields.

Definition at line 3694 of file qgsvectorlayer.cpp.

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

signal

void QgsVectorLayer::beforeCommitChanges ( )

signal

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

void QgsVectorLayer::beforeModifiedCheck ( ) const

signal

Is emitted, when layer is checked for modifications.

Use for last-minute additions

void QgsVectorLayer::beforeRollBack ( )

signal

Is emitted, before changes are rolled back.

void QgsVectorLayer::beginEditCommand

(

QString

text

)

Create edit command for undo/redo operations.

Parameters

text	text which is to be displayed in undo window

Definition at line 2772 of file qgsvectorlayer.cpp.

QgsRectangle QgsVectorLayer::boundingBoxOfSelected

(

)

Returns the bounding box of the selected features.

If there is no selection, QgsRectangle(0,0,0,0) is returned

Definition at line 654 of file qgsvectorlayer.cpp.

QgsGeometryCache* QgsVectorLayer::cache ( )

inline

Note

not available in python bindings

Definition at line 1468 of file qgsvectorlayer.h.

QString QgsVectorLayer::capabilitiesString

(

)

const

Capabilities for this layer in a friendly format.

Definition at line 226 of file qgsvectorlayer.cpp.

bool QgsVectorLayer::changeAttributeValue	(	QgsFeatureId	fid,
		int	field,
		QVariant	value,
		bool	emitSignal
	)

Changes an attribute value (but does not commit it)

Deprecated:

The emitSignal parameter is obsolete and not considered at the moment. It will be removed in future releases. Remove it to be prepared for the future. (Since 2.1)

Definition at line 2052 of file qgsvectorlayer.cpp.

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

Changes an attribute value (but does not commit it)

Parameters

fid	The feature id of the feature to be changed
field	The index of the field to be updated
newValue	The value which will be assigned to the field
oldValue	The previous value to restore on undo (will otherwise be retrieved)

Returns

true in case of success

Definition at line 2058 of file qgsvectorlayer.cpp.

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

change feature's geometry

Definition at line 2039 of file qgsvectorlayer.cpp.

void QgsVectorLayer::checkJoinLayerRemove ( QString  theLayerId )

slot

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

Definition at line 2831 of file qgsvectorlayer.cpp.

void QgsVectorLayer::clearAttributeEditorWidgets

(

)

Clears all the tabs for the attribute editor form.

Definition at line 3699 of file qgsvectorlayer.cpp.

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.

Definition at line 2232 of file qgsvectorlayer.cpp.

const QStringList & QgsVectorLayer::commitErrors

(

)

Definition at line 2277 of file qgsvectorlayer.cpp.

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

signal

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

signal

Signals emitted after committing changes.

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

signal

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

signal

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

signal

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

signal

bool QgsVectorLayer::countSymbolFeatures

(

bool

showProgress = true

)

Count features for symbols.

Feature counts may be get by featureCount( QgsSymbolV2*).

Parameters

showProgress

show progress dialog

Returns

true if calculated, false if failed or was canceled by user

Definition at line 731 of file qgsvectorlayer.cpp.

void QgsVectorLayer::createJoinCaches

(

)

Caches joined attributes if required (and not already done)

Definition at line 2887 of file qgsvectorlayer.cpp.

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

Reimplemented from QgsMapLayer.

Definition at line 403 of file qgsvectorlayer.cpp.

QString QgsVectorLayer::dataComment

(

)

const

Returns a comment for the data in the layer.

Definition at line 235 of file qgsvectorlayer.cpp.

QgsVectorDataProvider * QgsVectorLayer::dataProvider

(

)

Returns the data provider.

Definition at line 567 of file qgsvectorlayer.cpp.

const QgsVectorDataProvider * QgsVectorLayer::dataProvider

(

)

const

Returns the data provider in a const-correct manner.

Note

not available in python bindings

Definition at line 572 of file qgsvectorlayer.cpp.

QString QgsVectorLayer::dateFormat

(

int

idx

)

Access date format.

Deprecated:

Use setEditorWidgetV2Config() instead

Definition at line 2701 of file qgsvectorlayer.cpp.

bool QgsVectorLayer::deleteAttribute

(

int

attr

)

delete an attribute field (but does not commit it)

Definition at line 2150 of file qgsvectorlayer.cpp.

bool QgsVectorLayer::deleteAttributes

(

QList< int >

attrs

)

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

Parameters

attrs

the indices of the attributes to delete

Returns

true if at least one attribute has been deleted

Definition at line 2167 of file qgsvectorlayer.cpp.

bool QgsVectorLayer::deleteFeature

(

QgsFeatureId

fid

)

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

Definition at line 2187 of file qgsvectorlayer.cpp.

bool QgsVectorLayer::deleteSelectedFeatures

(

int *

deletedCount = 0

)

Deletes the selected features.

Returns

true in case of success and false otherwise

Definition at line 1036 of file qgsvectorlayer.cpp.

bool QgsVectorLayer::deleteVertex	(	QgsFeatureId	atFeatureId,
		int	atVertex
	)

Deletes a vertex from a feature.

Definition at line 1026 of file qgsvectorlayer.cpp.

void QgsVectorLayer::deselect ( const QgsFeatureId  featureId )

slot

Deselect feature by its ID.

Parameters

featureId

The id of the feature to deselect

See Also

deselect(QgsFeatureIds)

Definition at line 444 of file qgsvectorlayer.cpp.

void QgsVectorLayer::deselect ( const QgsFeatureIds &  featureIds )

slot

Deselect features by their ID.

Parameters

featureIds

The ids of the features to deselect

See Also

deselect(QgsFeatureId)

Definition at line 451 of file qgsvectorlayer.cpp.

void QgsVectorLayer::destroyEditCommand

(

)

Destroy active command and reverts all changes in it.

Definition at line 2798 of file qgsvectorlayer.cpp.

const QgsDiagramLayerSettings* QgsVectorLayer::diagramLayerSettings ( ) const

inline

Definition at line 774 of file qgsvectorlayer.h.

const QgsDiagramRendererV2* QgsVectorLayer::diagramRenderer ( ) const

inline

Definition at line 771 of file qgsvectorlayer.h.

const QString QgsVectorLayer::displayExpression

(

)

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

Definition at line 2583 of file qgsvectorlayer.cpp.

const QString QgsVectorLayer::displayField

(

)

const

Returns the primary display field name used in the identify results dialog.

Definition at line 2573 of file qgsvectorlayer.cpp.

bool QgsVectorLayer::draw ( QgsRenderContext &  rendererContext )

overridevirtual

Draws the layer.

Returns

false if an error occurred during drawing

Reimplemented from QgsMapLayer.

Definition at line 408 of file qgsvectorlayer.cpp.

void QgsVectorLayer::drawLabels ( QgsRenderContext &  rendererContext )

overridevirtual

Draws the layer labels using coordinate transformation.

Reimplemented from QgsMapLayer.

Definition at line 333 of file qgsvectorlayer.cpp.

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 414 of file qgsvectorlayer.cpp.

QgsVectorLayerEditBuffer* QgsVectorLayer::editBuffer ( )

inline

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

Definition at line 1409 of file qgsvectorlayer.h.

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()

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()

void QgsVectorLayer::editCommandStarted ( const QString &  text )

signal

Signal emitted when a new edit command has been started.

Parameters

text	Description for this edit command

QString QgsVectorLayer::editForm

(

)

get edit form

Definition at line 2653 of file qgsvectorlayer.cpp.

QString QgsVectorLayer::editFormInit

(

)

get python function for edit form initialization

Definition at line 2676 of file qgsvectorlayer.cpp.

void QgsVectorLayer::editingStarted ( )

signal

Is emitted, when editing on this layer has started.

void QgsVectorLayer::editingStopped ( )

signal

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

QgsVectorLayer::EditorLayout QgsVectorLayer::editorLayout

(

)

get the active layout for the attribute editor for this layer

Definition at line 2633 of file qgsvectorlayer.cpp.

const QString QgsVectorLayer::editorWidgetV2

(

int

fieldIdx

)

const

Get the id for the editor widget used to represent the field at the given index.

Parameters

fieldIdx

The index of the field

Returns

The id for the editor widget or a NULL string if not applicable

Definition at line 2103 of file qgsvectorlayer.cpp.

const QString QgsVectorLayer::editorWidgetV2

(

const QString &

fieldName

)

const

Get the id for the editor widget used to represent the field at the given index.

Parameters

fieldName

The name of the field

Returns

The id for the editor widget or a NULL string if not applicable

Note

python method name editorWidgetV2ByName

Definition at line 2111 of file qgsvectorlayer.cpp.

const QgsEditorWidgetConfig QgsVectorLayer::editorWidgetV2Config

(

int

fieldIdx

)

const

Get the configuration for the editor widget used to represent the field at the given index.

Parameters

fieldIdx

The index of the field

Returns

The configuration for the editor widget or an empty config if the field does not exist

Definition at line 2116 of file qgsvectorlayer.cpp.

const QgsEditorWidgetConfig QgsVectorLayer::editorWidgetV2Config

(

const QString &

fieldName

)

const

Get the configuration for the editor widget used to represent the field at the given index.

Parameters

fieldName

The name of the field

Returns

The configuration for the editor widget or an empty config if the field does not exist

Note

python method name is editorWidgetV2ConfigByName

Definition at line 2121 of file qgsvectorlayer.cpp.

QgsVectorLayer::EditType QgsVectorLayer::editType

(

int

idx

)

Get edit type.

Deprecated:

Use editorWidgetV2() instead

Definition at line 2614 of file qgsvectorlayer.cpp.

void QgsVectorLayer::enableLabels

(

bool

on

)

Set labels on.

Definition at line 1199 of file qgsvectorlayer.cpp.

void QgsVectorLayer::endEditCommand

(

)

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

Definition at line 2785 of file qgsvectorlayer.cpp.

const QSet<QString>& QgsVectorLayer::excludeAttributesWFS ( ) const

inline

Definition at line 1214 of file qgsvectorlayer.h.

const QSet<QString>& QgsVectorLayer::excludeAttributesWMS ( ) const

inline

Definition at line 1211 of file qgsvectorlayer.h.

QgsRectangle QgsVectorLayer::extent ( )

overridevirtual

Return the extent of the layer as a QRect.

Reimplemented from QgsMapLayer.

Definition at line 812 of file qgsvectorlayer.cpp.

void QgsVectorLayer::featureAdded ( QgsFeatureId  fid )

signal

QPainter::CompositionMode QgsVectorLayer::featureBlendMode

(

)

const

Read blend mode for layer.

Definition at line 3118 of file qgsvectorlayer.cpp.

void QgsVectorLayer::featureBlendModeChanged ( const QPainter::CompositionMode &  blendMode )

signal

Signal emitted when setFeatureBlendMode() is called.

long QgsVectorLayer::featureCount ( ) const

virtual

Number of features in the layer.

This is necessary if features are added/deleted or the layer has been subsetted. If the data provider chooses not to support this feature, the total number of features can be returned.

Returns

long containing number of features

Definition at line 714 of file qgsvectorlayer.cpp.

long QgsVectorLayer::featureCount

(

QgsSymbolV2 *

symbol

)

Number of features rendered with specified symbol.

Features must be first calculated by countSymbolFeatures()

Parameters

symbol

the symbol

Returns

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

Definition at line 725 of file qgsvectorlayer.cpp.

void QgsVectorLayer::featureDeleted ( QgsFeatureId  fid )

signal

QgsVectorLayer::FeatureFormSuppress QgsVectorLayer::featureFormSuppress ( ) const

inline

Type of feature form pop-up suppression after feature creation (overrides app setting)

Note

added in 2.1

Definition at line 1340 of file qgsvectorlayer.h.

bool QgsVectorLayer::fieldEditable

(

int

idx

)

is edit widget editable

Definition at line 2712 of file qgsvectorlayer.cpp.

int QgsVectorLayer::fieldNameIndex

(

const QString &

fieldName

)

const

Returns the index of a field name or -1 if the field does not exist.

Definition at line 2821 of file qgsvectorlayer.cpp.

void QgsVectorLayer::geometryChanged ( QgsFeatureId  fid, QgsGeometry &  geom  )

signal

QGis::GeometryType QgsVectorLayer::geometryType

(

)

const

Returns point, line or polygon.

Definition at line 592 of file qgsvectorlayer.cpp.

QgsFeatureIterator QgsVectorLayer::getFeatures

(

const QgsFeatureRequest &

request = QgsFeatureRequest()

)

Query the provider for features specified in request.

Definition at line 939 of file qgsvectorlayer.cpp.

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

virtual

Will return the named style corresponding to style id provided.

Definition at line 3772 of file qgsvectorlayer.cpp.

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 643 of file qgsvectorlayer.cpp.

bool QgsVectorLayer::hasLabelsEnabled

(

void

)

const

Label is on.

Definition at line 1204 of file qgsvectorlayer.cpp.

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

snapResults

results collected from the snapping operation

Returns

0 in case of success

Definition at line 2545 of file qgsvectorlayer.cpp.

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 1006 of file qgsvectorlayer.cpp.

void QgsVectorLayer::invalidateSymbolCountedFlag ( )

protectedslot

Definition at line 3634 of file qgsvectorlayer.cpp.

void QgsVectorLayer::invertSelection

(

)

Select not selected features and deselect selected ones.

Definition at line 501 of file qgsvectorlayer.cpp.

void QgsVectorLayer::invertSelectionInRectangle

(

QgsRectangle &

rect

)

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

Parameters

rect	The rectangle in which the selection of features will be inverted

See Also

invertSelection()

Definition at line 530 of file qgsvectorlayer.cpp.

bool QgsVectorLayer::isEditable ( ) const

overridevirtual

Returns true if the provider is in editing mode.

Reimplemented from QgsMapLayer.

Definition at line 2588 of file qgsvectorlayer.cpp.

bool QgsVectorLayer::isModified ( ) const

virtual

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

Definition at line 2608 of file qgsvectorlayer.cpp.

bool QgsVectorLayer::isReadOnly ( ) const

virtual

Returns true if the provider is in read-only mode.

Definition at line 2593 of file qgsvectorlayer.cpp.

QgsLabel * QgsVectorLayer::label

(

)

Get the label object associated with this layer.

Definition at line 1189 of file qgsvectorlayer.cpp.

const QgsLabel * QgsVectorLayer::label

(

)

const

Definition at line 1194 of file qgsvectorlayer.cpp.

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

signal

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

bool QgsVectorLayer::labelOnTop

(

int

idx

)

label widget on top

Definition at line 2726 of file qgsvectorlayer.cpp.

void QgsVectorLayer::layerDeleted ( )

signal

void QgsVectorLayer::layerModified ( )

signal

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

int QgsVectorLayer::layerTransparency

(

)

const

Read transparency for layer.

Definition at line 3131 of file qgsvectorlayer.cpp.

void QgsVectorLayer::layerTransparencyChanged ( int  layerTransparency )

signal

Signal emitted when setLayerTransparency() is called.

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

ids	the list in which will be stored the style db ids
names	the list in which will be stored the style names
descriptions	the list in which will be stored the style descriptions
msgError

Returns

the number of styles related to current layer

Definition at line 3751 of file qgsvectorlayer.cpp.

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

virtual

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

Parameters

theURI	the URI of the style or the URI of the layer
theResultFlag	will be set to true if a named style is correctly loaded
loadFromLocalDb	if true forces to load from local db instead of datasource one

Definition at line 3841 of file qgsvectorlayer.cpp.

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

overridevirtual

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

Reimplemented from QgsMapLayer.

Definition at line 3836 of file qgsvectorlayer.cpp.

QVariant QgsVectorLayer::maximumValue

(

int

index

)

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

Definition at line 3048 of file qgsvectorlayer.cpp.

QString QgsVectorLayer::metadata ( )

overridevirtual

Obtain Metadata for this layer.

Reimplemented from QgsMapLayer.

Definition at line 3380 of file qgsvectorlayer.cpp.

QVariant QgsVectorLayer::minimumValue

(

int

index

)

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

Definition at line 2986 of file qgsvectorlayer.cpp.

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

Modifies the current selection on this layer.

Parameters

selectIds	Select these ids
deselectIds	Deselect these ids

See Also

select(QgsFeatureIds)

select(QgsFeatureId)

deselect(QgsFeatureIds)

deselect(QgsFeatureId)

Definition at line 487 of file qgsvectorlayer.cpp.

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 1016 of file qgsvectorlayer.cpp.

QgsAttributeList QgsVectorLayer::pendingAllAttributesList

(

)

returns list of attributes

Definition at line 2206 of file qgsvectorlayer.cpp.

int QgsVectorLayer::pendingFeatureCount

(

)

returns feature count after commit

Definition at line 2226 of file qgsvectorlayer.cpp.

const QgsFields & QgsVectorLayer::pendingFields

(

)

const

returns field list in the to-be-committed state

Definition at line 2201 of file qgsvectorlayer.cpp.

QgsAttributeList QgsVectorLayer::pendingPkAttributesList

(

)

returns list of attribute making up the primary key

Definition at line 2211 of file qgsvectorlayer.cpp.

QString QgsVectorLayer::providerType

(

)

const

Return the provider type for this layer.

Definition at line 245 of file qgsvectorlayer.cpp.

QgsVectorLayer::RangeData QgsVectorLayer::range

(

int

idx

)

Access range widget config data.

Deprecated:

Use editorWidgetV2Config() instead

Definition at line 2691 of file qgsvectorlayer.cpp.

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

element	The XML layer style element.
errorMessage	Write error messages into this string.

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

overridevirtual

Reimplemented from QgsMapLayer.

Definition at line 1998 of file qgsvectorlayer.cpp.

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

overridevirtual

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

Parameters

node	node that will contain the symbology definition for this layer.
errorMessage	reference to string that will be updated with any error messages

Returns

true in case of success.

Implements QgsMapLayer.

Definition at line 1513 of file qgsvectorlayer.cpp.

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 1274 of file qgsvectorlayer.cpp.

QList< QgsRelation > QgsVectorLayer::referencingRelations

(

int

idx

)

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

Parameters

idx	Only get relations, where idx forms part of the foreign key

Returns

A list of relations

Definition at line 3689 of file qgsvectorlayer.cpp.

void QgsVectorLayer::reload ( )

overridevirtual

Synchronises with changes in the datasource.

Reimplemented from QgsMapLayer.

Definition at line 395 of file qgsvectorlayer.cpp.

void QgsVectorLayer::remAttributeAlias

(

int

attIndex

)

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

Definition at line 2074 of file qgsvectorlayer.cpp.

void QgsVectorLayer::removeExpressionField

(

int

index

)

Remove an expression field.

Parameters

index

The index of the field

Note

added in 2.6

Definition at line 2854 of file qgsvectorlayer.cpp.

void QgsVectorLayer::removeJoin

(

const QString &

joinLayerId

)

Removes a vector layer join.

Definition at line 2836 of file qgsvectorlayer.cpp.

int QgsVectorLayer::removePolygonIntersections	(	QgsGeometry *	geom,
		QgsFeatureIds	ignoreFeatures = QgsFeatureIds()
	)

Changes the specified geometry such that it has no intersections with other polygon (or multipolygon) geometries in this vector layer.

Parameters

geom	geometry to modify
ignoreFeatures	list of feature ids where intersections should be ignored

Returns

0 in case of success

Deprecated:

since 2.2 - not being used for "avoid intersections" functionality anymore

Definition at line 1127 of file qgsvectorlayer.cpp.

void QgsVectorLayer::removeSelection ( )

slot

Clear selection.

See Also

setSelectedFeatures(const QgsFeatureIds&)

Definition at line 559 of file qgsvectorlayer.cpp.

QgsFeatureRendererV2 * QgsVectorLayer::rendererV2

(

)

Return renderer V2.

Definition at line 2749 of file qgsvectorlayer.cpp.

bool QgsVectorLayer::rollBack

(

bool

deleteBuffer = true

)

Stop editing and discard the edits.

Parameters

deleteBuffer

whether to delete editing buffer

Definition at line 2282 of file qgsvectorlayer.cpp.

void QgsVectorLayer::saveLayerToProject ( )

signal

void QgsVectorLayer::saveStyleToDatabase ( QString  name, QString  description, bool  useAsDefault, 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 3794 of file qgsvectorlayer.cpp.

void QgsVectorLayer::select	(	QgsRectangle &	rect,
		bool	addToSelection
	)

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

Parameters

rect	The search rectangle
addToSelection	If set to true will not clear before selecting

See Also

invertSelectionInRectangle(QgsRectangle & rect)

Definition at line 458 of file qgsvectorlayer.cpp.

void QgsVectorLayer::select ( const QgsFeatureId &  featureId )

slot

Select feature by its ID.

Parameters

featureId

The id of the feature to select

See Also

select(QgsFeatureIds)

Definition at line 430 of file qgsvectorlayer.cpp.

void QgsVectorLayer::select ( const QgsFeatureIds &  featureIds )

slot

Select features by their ID.

Parameters

featureIds

The ids of the features to select

See Also

select(QgsFeatureId)

Definition at line 437 of file qgsvectorlayer.cpp.

void QgsVectorLayer::selectAll

(

)

Select all the features.

Definition at line 508 of file qgsvectorlayer.cpp.

int QgsVectorLayer::selectedFeatureCount

(

)

The number of features that are selected in this layer.

Returns

See description

Definition at line 2328 of file qgsvectorlayer.cpp.

QgsFeatureList QgsVectorLayer::selectedFeatures

(

)

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 2338 of file qgsvectorlayer.cpp.

const QgsFeatureIds & QgsVectorLayer::selectedFeaturesIds

(

)

const

Return reference to identifiers of selected features.

Returns

A list of QgsFeatureId 's

See Also

selectedFeatures()

Definition at line 2333 of file qgsvectorlayer.cpp.

QgsFeatureIterator QgsVectorLayer::selectedFeaturesIterator

(

QgsFeatureRequest

request = QgsFeatureRequest()

)

Get an iterator of the selected features.

Parameters

request

You 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 2366 of file qgsvectorlayer.cpp.

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

signal

This signal is emitted when selection was changed.

Parameters

selected	Newly selected feature ids
deselected	Ids of all features which have previously been selected but are not any more
clearAndSelect	In case this is set to true, the old selection was dismissed and the new selection corresponds to selected

void QgsVectorLayer::selectionChanged ( )

signal

This signal is emitted when selection was changed.

void QgsVectorLayer::setAnnotationForm

(

const QString &

ui

)

set annotation form for layer

Definition at line 2671 of file qgsvectorlayer.cpp.

void QgsVectorLayer::setCheckedState	(	int	idx,
		QString	checked,
		QString	notChecked
	)

Set string representing 'true' for a checkbox.

Deprecated:

Use setEditorWidgetV2Config() instead

Definition at line 2813 of file qgsvectorlayer.cpp.

void QgsVectorLayer::setCoordinateSystem

(

)

Setup the coordinate system transformation for the layer.

Definition at line 2552 of file qgsvectorlayer.cpp.

void QgsVectorLayer::setDiagramLayerSettings

(

const QgsDiagramLayerSettings &

s

)

Definition at line 3373 of file qgsvectorlayer.cpp.

void QgsVectorLayer::setDiagramRenderer

(

QgsDiagramRendererV2 *

r

)

Sets diagram rendering object (takes ownership)

Definition at line 586 of file qgsvectorlayer.cpp.

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

displayExpression

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

Definition at line 2578 of file qgsvectorlayer.cpp.

void QgsVectorLayer::setDisplayField

(

QString

fldName = ""

)

Set the primary display field to be used in the identify results dialog.

sets the preferred display field based on some fuzzy logic

Definition at line 253 of file qgsvectorlayer.cpp.

void QgsVectorLayer::setEditForm

(

QString

ui

)

set edit form

Definition at line 2658 of file qgsvectorlayer.cpp.

void QgsVectorLayer::setEditFormInit

(

QString

function

)

set python function for edit form initialization

Definition at line 2681 of file qgsvectorlayer.cpp.

void QgsVectorLayer::setEditorLayout

(

EditorLayout

editorLayout

)

set the active layout for the attribute editor for this layer

Definition at line 2638 of file qgsvectorlayer.cpp.

void QgsVectorLayer::setEditorWidgetV2	(	int	attrIdx,
		const QString &	widgetType
	)

Set the editor widget type for a field.

QGIS ships the following widget types, additional types may be available depending on plugins.

• CheckBox (QgsCheckboxWidgetWrapper)
• Classification (QgsClassificationWidgetWrapper)
• Color (QgsColorWidgetWrapper)
• DateTime (QgsDateTimeEditWrapper)
• Enumeration (QgsEnumerationWidgetWrapper)
• FileName (QgsFileNameWidgetWrapper)
• Hidden (QgsHiddenWidgetWrapper)
• Photo (QgsPhotoWidgetWrapper)
• Range (QgsRangeWidgetWrapper)
• RelationReference (QgsRelationReferenceWidgetWrapper)
• TextEdit (QgsTextEditWrapper)
• UniqueValues (QgsUniqueValuesWidgetWrapper)
• UuidGenerator (QgsUuidWidgetWrapper)
• ValueMap (QgsValueMapWidgetWrapper)
• ValueRelation (QgsValueRelationWidgetWrapper)
• WebView (QgsWebViewWidgetWrapper)

Parameters

attrIdx	Index of the field
widgetType	Type id of the editor widget to use

Definition at line 2643 of file qgsvectorlayer.cpp.

void QgsVectorLayer::setEditorWidgetV2Config	(	int	attrIdx,
		const QgsEditorWidgetConfig &	config
	)

Set the editor widget config for a field.

Python: Will accept a map.

Example:

layer.setEditorWidgetV2Config( 1, { 'Layer': 'otherlayerid_1234', 'Key': 'Keyfield', 'Value': 'ValueField' } )

Parameters

attrIdx	Index of the field
config	The config to set for this field

See Also

setEditorWidgetV2() for a list of widgets and choose the widget to see the available options.

Definition at line 2648 of file qgsvectorlayer.cpp.

void QgsVectorLayer::setEditType	(	int	idx,
		EditType	edit
	)

Get edit type.

Deprecated:

Use setEditorWidgetV2() instead

Definition at line 2621 of file qgsvectorlayer.cpp.

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

inline

Definition at line 1215 of file qgsvectorlayer.h.

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

inline

Definition at line 1212 of file qgsvectorlayer.h.

void QgsVectorLayer::setExtent ( const QgsRectangle &  rect )

overrideprotectedvirtual

Set the extent.

Reimplemented from QgsMapLayer.

Definition at line 806 of file qgsvectorlayer.cpp.

void QgsVectorLayer::setFeatureBlendMode

(

const QPainter::CompositionMode &

blendMode

)

Write blend mode for features.

Definition at line 3111 of file qgsvectorlayer.cpp.

void QgsVectorLayer::setFeatureFormSuppress ( QgsVectorLayer::FeatureFormSuppress  s )

inline

Set type of feature form pop-up suppression after feature creation (overrides app setting)

Note

added in 2.1

Definition at line 1344 of file qgsvectorlayer.h.

void QgsVectorLayer::setFieldEditable	(	int	idx,
		bool	editable
	)

set edit widget editable

Definition at line 2735 of file qgsvectorlayer.cpp.

void QgsVectorLayer::setLabelOnTop	(	int	idx,
		bool	onTop
	)

label widget on top

Definition at line 2742 of file qgsvectorlayer.cpp.

void QgsVectorLayer::setLayerTransparency

(

int

layerTransparency

)

Write transparency for layer.

Definition at line 3124 of file qgsvectorlayer.cpp.

void QgsVectorLayer::setProviderEncoding

(

const QString &

encoding

)

Sets the textencoding of the data provider.

Definition at line 577 of file qgsvectorlayer.cpp.

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 2598 of file qgsvectorlayer.cpp.

void QgsVectorLayer::setRendererV2

(

QgsFeatureRendererV2 *

r

)

Set renderer V2.

Definition at line 2754 of file qgsvectorlayer.cpp.

void QgsVectorLayer::setSelectedFeatures

(

const QgsFeatureIds &

ids

)

Change selection to the new set of features.

Dismisses the current selection. Will emit the selectionChanged( QgsFeatureIds, QgsFeatureIds, bool ) signal with the clearAndSelect flag set.

Parameters

ids	The ids which will be the new selection

Definition at line 2319 of file qgsvectorlayer.cpp.

void QgsVectorLayer::setSimplifyMethod ( const QgsVectorSimplifyMethod &  simplifyMethod )

inline

Set the simplification settings for fast rendering of features.

Note

added in 2.2

Definition at line 1473 of file qgsvectorlayer.h.

bool QgsVectorLayer::setSubsetString ( QString  subset )

virtual

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

Parameters

subset

The 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 904 of file qgsvectorlayer.cpp.

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 924 of file qgsvectorlayer.cpp.

const QgsVectorSimplifyMethod& QgsVectorLayer::simplifyMethod ( ) const

inline

Returns the simplification settings for fast rendering of features.

Note

added in 2.2

Definition at line 1477 of file qgsvectorlayer.h.

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

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

Parameters

point	The 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.
tolerance	The snapping tolerance

Returns

true if the point has been snapped, false if no vertex within search tolerance

Definition at line 2405 of file qgsvectorlayer.cpp.

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

startPoint	point to snap (in layer coordinates)
snappingTolerance	distance tolerance for snapping
snappingResults	snapping results. Key is the distance between startPoint and snapping target
snap_to	to segment / to vertex

Returns

0 in case of success

Definition at line 2430 of file qgsvectorlayer.cpp.

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

Splits features cut by the given line.

Parameters

splitLine	line that splits the layer features
topologicalEditing	true if topological editing is enabled

Returns

0 in case of success, 4 if there is a selection but no feature split

Definition at line 1118 of file qgsvectorlayer.cpp.

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

Splits parts cut by the given line.

Parameters

splitLine	line that splits the layer features
topologicalEditing	true if topological editing is enabled

Returns

0 in case of success, 4 if there is a selection but no feature split

Definition at line 1109 of file qgsvectorlayer.cpp.

bool QgsVectorLayer::startEditing

(

)

Make layer editable.

Definition at line 1209 of file qgsvectorlayer.cpp.

QString QgsVectorLayer::storageType

(

)

const

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

Definition at line 216 of file qgsvectorlayer.cpp.

QString QgsVectorLayer::subsetString ( )

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 894 of file qgsvectorlayer.cpp.

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

Translates feature by dx, dy.

Parameters

featureId	id of the feature to translate
dx	translation of x-coordinate
dy	translation of y-coordinate

Returns

0 in case of success

Definition at line 1100 of file qgsvectorlayer.cpp.

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

Returns unique values for column.

Parameters

index	column index for attribute
uniqueValues	out: result list
limit	maximum number of values to return (-1 if unlimited)

Definition at line 2895 of file qgsvectorlayer.cpp.

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.

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 801 of file qgsvectorlayer.cpp.

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

f	Feature to update

Returns

True in case of success and False in case of error

Definition at line 962 of file qgsvectorlayer.cpp.

void QgsVectorLayer::updateFields

(

)

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

Definition at line 2862 of file qgsvectorlayer.cpp.

QMap< QString, QVariant > QgsVectorLayer::valueMap

(

int

idx

)

Access value map.

Deprecated:

Use editorWidgetV2Config() instead

Definition at line 2686 of file qgsvectorlayer.cpp.

QgsVectorLayer::ValueRelationData QgsVectorLayer::valueRelation

(

int

idx

)

Access value relation widget data.

Definition at line 3668 of file qgsvectorlayer.cpp.

const QList< QgsVectorJoinInfo > & QgsVectorLayer::vectorJoins

(

)

const

Definition at line 2841 of file qgsvectorlayer.cpp.

QSize QgsVectorLayer::widgetSize

(

int

idx

)

Access widget size for photo and webview widget.

Deprecated:

Use setEditorWidgetV2Config() instead

Definition at line 2706 of file qgsvectorlayer.cpp.

QGis::WkbType QgsVectorLayer::wkbType

(

)

const

Returns the WKBType or WKBUnknown in case of error.

Definition at line 649 of file qgsvectorlayer.cpp.

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

element	The XML element where you can add additional style information to.
doc	The XML document that you can use to create new XML nodes.
errorMessage	Write error messages into this string.

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

Definition at line 2022 of file qgsvectorlayer.cpp.

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

overridevirtual

Write the symbology for the layer into the docment provided.

Parameters

node	the node that will have the style element added to it.
doc	the document that will have the QDomNode added.
errorMessage	reference to string that will be updated with any error messages

Returns

true in case of success.

Implements QgsMapLayer.

Definition at line 1795 of file qgsvectorlayer.cpp.

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

overridevirtual

write vector layer specific state to project file Dom node.

Note

Called by QgsMapLayer::writeXML().

Reimplemented from QgsMapLayer.

Definition at line 1466 of file qgsvectorlayer.cpp.

Friends And Related Function Documentation

friend class QgsVectorLayerEditBuffer

friend

Definition at line 1805 of file qgsvectorlayer.h.

friend class QgsVectorLayerFeatureSource

friend

Definition at line 1828 of file qgsvectorlayer.h.

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

• /tmp/buildd/qgis-2.8.2+12wheezy/src/core/qgsvectorlayer.h
• /tmp/buildd/qgis-2.8.2+12wheezy/src/core/qgsvectorlayer.cpp