Class: QgsVirtualLayerDefinition¶
- class qgis.core.QgsVirtualLayerDefinition¶
Bases:
sip.wrapper
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.
QgsVirtualLayerDefinition(filePath: str = ‘’) Constructor with an optional file path
QgsVirtualLayerDefinition(
QgsVirtualLayerDefinition
)Methods
Add a live layer source layer
Gets field definitions
Gets the file path.
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.
Gets the name of the geometry field.
Gets the SRID of the geometry
Gets the type of the geometry
QgsWkbTypes
.NoGeometry to hide any geometryQgsWkbTypes
.Unknown for unknown typesConvenient method to test if the geometry is defined (not NoGeometry and not Unknown)
Convenience method to test whether the definition has referenced (live) layers
Convenience method to test if a given source layer is part of the definition
Returns the lazy mode.
Gets the SQL query
Sets field definitions
Sets the file path
Sets the name of the geometry field
Sets the SRID of the geometry
Sets the type of the geometry
Sets the lazy mode.
Sets the SQL query
Sets the
subsetString
Sets the name of the field with unique identifiers
Gets access to the source layers
Returns the subset string.
Convert into a QString that can be read by the virtual layer provider
Convert the definition into a QUrl
Gets the name of the field with unique identifiers
- class SourceLayer¶
Bases:
sip.wrapper
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.)
QgsVirtualLayerDefinition.SourceLayer(name: str, ref: str) 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)
- encoding(self) str ¶
Optional encoding for the provider
- Return type:
str
- isReferenced(self) bool ¶
Is it a live layer or not ?
- Return type:
bool
- name(self) str ¶
Name of the layer
- Return type:
str
- provider(self) str ¶
Provider key
- Return type:
str
- reference(self) str ¶
The reference (id) of the live layer
- Return type:
str
- source(self) str ¶
The source url used by the provider to build the layer
- Return type:
str
- 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
- Parameters:
name (str) –
ref (str) –
- filePath(self) str ¶
Gets the file path. May be empty
- Return type:
str
- 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 subsetstring=subset_string represents the subsetstring
- Parameters:
url (QUrl) –
- Return type:
- geometryField(self) str ¶
Gets the name of the geometry field. Empty if no geometry field
- Return type:
str
- geometrySrid(self) int ¶
Gets the SRID of the geometry
- Return type:
int
- geometryWkbType(self) Qgis.WkbType ¶
Gets the type of the geometry
QgsWkbTypes
.NoGeometry to hide any geometryQgsWkbTypes
.Unknown for unknown types- Return type:
- hasDefinedGeometry(self) bool ¶
Convenient method to test if the geometry is defined (not NoGeometry and not Unknown)
- Return type:
bool
- hasReferencedLayers(self) bool ¶
Convenience method to test whether the definition has referenced (live) layers
- Return type:
bool
- hasSourceLayer(self, name: str) bool ¶
Convenience method to test if a given source layer is part of the definition
- Parameters:
name (str) –
- Return type:
bool
- isLazy(self) bool ¶
Returns the lazy mode.
- Return type:
bool
- Returns:
True
if the loading is delayed,False
otherwise.
See also
New in version 3.2.
- query(self) str ¶
Gets the SQL query
- Return type:
str
- setFilePath(self, filePath: str)¶
Sets the file path
- Parameters:
filePath (str) –
- setGeometryField(self, geometryField: str)¶
Sets the name of the geometry field
- Parameters:
geometryField (str) –
- setGeometrySrid(self, srid: int)¶
Sets the SRID of the geometry
- Parameters:
srid (int) –
- setGeometryWkbType(self, t: Qgis.WkbType)¶
Sets the type of the geometry
- Parameters:
t (Qgis.WkbType) –
- setLazy(self, lazy: bool)¶
Sets the lazy mode. If
lazy
isTrue
, then the loading is delayed until an explicit reloading of the layer.- Parameters:
lazy (bool) –
True
to delay the loading,False
otherwise
See also
See also
New in version 3.2.
- setQuery(self, query: str)¶
Sets the SQL query
- Parameters:
query (str) –
- setSubsetString(self, subsetString: str)¶
Sets the
subsetString
New in version 3.16.
- Parameters:
subsetString (str) –
- setUid(self, uid: str)¶
Sets the name of the field with unique identifiers
- Parameters:
uid (str) –
- sourceLayers(self) List[QgsVirtualLayerDefinition.SourceLayer] ¶
Gets access to the source layers
- Return type:
- subsetString(self) str ¶
Returns the subset string.
New in version 3.16.
- Return type:
str
- toString(self) str ¶
Convert into a QString that can be read by the virtual layer provider
- Return type:
str
- toUrl(self) QUrl ¶
Convert the definition into a QUrl
- Return type:
QUrl
- uid(self) str ¶
Gets the name of the field with unique identifiers
- Return type:
str