Class: QgsVirtualLayerDefinition¶

class qgis.core.QgsVirtualLayerDefinition(filePath: str = '')¶

Bases: sip.wrapper

Constructor with an optional file path

QgsVirtualLayerDefinition(QgsVirtualLayerDefinition)

Class to manipulate the definition of a virtual layer

It is used to extract parameters from an initial virtual layer definition as well as to store the complete, expanded definition once types have been detected.

Enums

Methods

addSource

Add a live layer source layer

fields

Gets field definitions

filePath

Gets the file path.

fromUrl

Constructor to build a definition from a QUrl The path part of the URL is extracted as well as the following optional keys: layer_ref=layer_id[:name] represents a live layer referenced by its ID.

geometryField

Gets the name of the geometry field.

geometrySrid

Gets the SRID of the geometry

geometryWkbType

Gets the type of the geometry QgsWkbTypes.NoGeometry to hide any geometry QgsWkbTypes.Unknown for unknown types

hasDefinedGeometry

Convenient method to test if the geometry is defined (not NoGeometry and not Unknown)

hasReferencedLayers

Convenience method to test whether the definition has referenced (live) layers

hasSourceLayer

Convenience method to test if a given source layer is part of the definition

isLazy

Returns the lazy mode.

query

Gets the SQL query

setFields

Sets field definitions

setFilePath

Sets the file path

setGeometryField

Sets the name of the geometry field

setGeometrySrid

Sets the SRID of the geometry

setGeometryWkbType

Sets the type of the geometry

setLazy

Sets the lazy mode.

setQuery

Sets the SQL query

setUid

Sets the name of the field with unique identifiers

sourceLayers

Gets access to the source layers

toString

Convert into a QString that can be read by the virtual layer provider

toUrl

Convert the definition into a QUrl

uid

Gets the name of the field with unique identifiers

Signals

Attributes

class SourceLayer(name: str, ref: str)¶

Bases: sip.wrapper

Constructor variant to build a live layer reference

QgsVirtualLayerDefinition.SourceLayer(name: str, source: str, provider: str, encoding: str) Constructor variant to build a layer with a provider and a source

QgsVirtualLayerDefinition.SourceLayer(QgsVirtualLayerDefinition.SourceLayer)

A SourceLayer is either a reference to a live layer in the registry or all the parameters needed to load it (provider key, source, etc.)

encoding(self) → str¶: Optional encoding for the provider

isReferenced(self) → bool¶: Is it a live layer or not ?

name(self) → str¶: Name of the layer

provider(self) → str¶: Provider key

reference(self) → str¶: The reference (id) of the live layer

source(self) → str¶: The source url used by the provider to build the layer

addSource(self, name: str, ref: str)¶

Add a live layer source layer

addSource(self, name: str, source: str, provider: str, encoding: str = ‘’) Add a layer with a source, a provider and an encoding

fields(self) → QgsFields¶: Gets field definitions

filePath(self) → str¶: Gets the file path. May be empty

fromUrl(url: QUrl) → QgsVirtualLayerDefinition¶: Constructor to build a definition from a QUrl The path part of the URL is extracted as well as the following optional keys: layer_ref=layer_id[:name] represents a live layer referenced by its ID. An optional name can be given layer=provider:source[:name[:encoding]] represents a layer given by its provider key, its source url (URL-encoded). An optional name and encoding can be given geometry=column_name[:type:srid] gives the definition of the geometry column. Type can be either a WKB type code or a string (point, linestring, etc.) srid is an integer uid=column_name is the name of a column with unique integer values. nogeometry is a flag to force the layer to be a non-geometry layer query=sql represents the SQL query. Must be URL-encoded field=column_name:[int|real|text] represents a field with its name and its type

geometryField(self) → str¶: Gets the name of the geometry field. Empty if no geometry field

geometrySrid(self) → int¶: Gets the SRID of the geometry

geometryWkbType(self) → QgsWkbTypes.Type¶: Gets the type of the geometry QgsWkbTypes.NoGeometry to hide any geometry QgsWkbTypes.Unknown for unknown types

hasDefinedGeometry(self) → bool¶: Convenient method to test if the geometry is defined (not NoGeometry and not Unknown)

hasReferencedLayers(self) → bool¶: Convenience method to test whether the definition has referenced (live) layers

hasSourceLayer(self, name: str) → bool¶: Convenience method to test if a given source layer is part of the definition

isLazy(self) → bool¶

Returns the lazy mode.

Returns: True if the loading is delayed, false otherwise.