QGIS API Documentation  3.37.0-Master (a5b4d9743e8)
Classes | Public Types | Public Member Functions | Static Public Member Functions | List of all members
QgsVirtualLayerDefinition Class Reference

Class to manipulate the definition of a virtual layer. More...

#include <qgsvirtuallayerdefinition.h>

Classes

class  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.) More...
 

Public Types

typedef QList< QgsVirtualLayerDefinition::SourceLayerSourceLayers
 List of source layers. More...
 

Public Member Functions

 QgsVirtualLayerDefinition (const QString &filePath="")
 Constructor with an optional file path. More...
 
void addSource (const QString &name, const QString &ref)
 Add a live layer source layer. More...
 
void addSource (const QString &name, const QString &source, const QString &provider, const QString &encoding="")
 Add a layer with a source, a provider and an encoding. More...
 
QgsFields fields () const
 Gets field definitions. More...
 
QString filePath () const
 Gets the file path. May be empty. More...
 
QString geometryField () const
 Gets the name of the geometry field. Empty if no geometry field. More...
 
long geometrySrid () const
 Gets the SRID of the geometry. More...
 
Qgis::WkbType geometryWkbType () const
 Gets the type of the geometry QgsWkbTypes::NoGeometry to hide any geometry QgsWkbTypes::Unknown for unknown types. More...
 
bool hasDefinedGeometry () const
 Convenient method to test if the geometry is defined (not NoGeometry and not Unknown) More...
 
bool hasReferencedLayers () const
 Convenience method to test whether the definition has referenced (live) layers. More...
 
bool hasSourceLayer (const QString &name) const
 Convenience method to test if a given source layer is part of the definition. More...
 
bool isLazy () const
 Returns the lazy mode. More...
 
QString query () const
 Gets the SQL query. More...
 
void setFields (const QgsFields &fields)
 Sets field definitions. More...
 
void setFilePath (const QString &filePath)
 Sets the file path. More...
 
void setGeometryField (const QString &geometryField)
 Sets the name of the geometry field. More...
 
void setGeometrySrid (long srid)
 Sets the SRID of the geometry. More...
 
void setGeometryWkbType (Qgis::WkbType t)
 Sets the type of the geometry. More...
 
void setLazy (bool lazy)
 Sets the lazy mode. More...
 
void setQuery (const QString &query)
 Sets the SQL query. More...
 
void setSubsetString (const QString &subsetString)
 Sets the subsetString. More...
 
void setUid (const QString &uid)
 Sets the name of the field with unique identifiers. More...
 
const QgsVirtualLayerDefinition::SourceLayerssourceLayers () const
 Gets access to the source layers. More...
 
QString subsetString () const
 Returns the subset string. More...
 
QString toString () const
 Convert into a QString that can be read by the virtual layer provider. More...
 
QUrl toUrl () const
 Convert the definition into a QUrl. More...
 
QString uid () const
 Gets the name of the field with unique identifiers. More...
 

Static Public Member Functions

static QgsVirtualLayerDefinition fromUrl (const QUrl &url)
 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. More...
 

Detailed Description

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.

Definition at line 31 of file qgsvirtuallayerdefinition.h.

Member Typedef Documentation

◆ SourceLayers

List of source layers.

Definition at line 115 of file qgsvirtuallayerdefinition.h.

Constructor & Destructor Documentation

◆ QgsVirtualLayerDefinition()

QgsVirtualLayerDefinition::QgsVirtualLayerDefinition ( const QString &  filePath = "")

Constructor with an optional file path.

Definition at line 26 of file qgsvirtuallayerdefinition.cpp.

Member Function Documentation

◆ addSource() [1/2]

void QgsVirtualLayerDefinition::addSource ( const QString &  name,
const QString &  ref 
)

Add a live layer source layer.

Definition at line 252 of file qgsvirtuallayerdefinition.cpp.

◆ addSource() [2/2]

void QgsVirtualLayerDefinition::addSource ( const QString &  name,
const QString &  source,
const QString &  provider,
const QString &  encoding = "" 
)

Add a layer with a source, a provider and an encoding.

Definition at line 257 of file qgsvirtuallayerdefinition.cpp.

◆ fields()

QgsFields QgsVirtualLayerDefinition::fields ( ) const
inline

Gets field definitions.

Definition at line 173 of file qgsvirtuallayerdefinition.h.

◆ filePath()

QString QgsVirtualLayerDefinition::filePath ( ) const
inline

Gets the file path. May be empty.

Definition at line 126 of file qgsvirtuallayerdefinition.h.

◆ fromUrl()

QgsVirtualLayerDefinition QgsVirtualLayerDefinition::fromUrl ( const QUrl &  url)
static

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

Definition at line 31 of file qgsvirtuallayerdefinition.cpp.

◆ geometryField()

QString QgsVirtualLayerDefinition::geometryField ( ) const
inline

Gets the name of the geometry field. Empty if no geometry field.

Definition at line 154 of file qgsvirtuallayerdefinition.h.

◆ geometrySrid()

long QgsVirtualLayerDefinition::geometrySrid ( ) const
inline

Gets the SRID of the geometry.

Definition at line 168 of file qgsvirtuallayerdefinition.h.

◆ geometryWkbType()

Qgis::WkbType QgsVirtualLayerDefinition::geometryWkbType ( ) const
inline

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

Definition at line 163 of file qgsvirtuallayerdefinition.h.

◆ hasDefinedGeometry()

bool QgsVirtualLayerDefinition::hasDefinedGeometry ( ) const
inline

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

Definition at line 184 of file qgsvirtuallayerdefinition.h.

◆ hasReferencedLayers()

bool QgsVirtualLayerDefinition::hasReferencedLayers ( ) const

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

Definition at line 275 of file qgsvirtuallayerdefinition.cpp.

◆ hasSourceLayer()

bool QgsVirtualLayerDefinition::hasSourceLayer ( const QString &  name) const

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

Definition at line 262 of file qgsvirtuallayerdefinition.cpp.

◆ isLazy()

bool QgsVirtualLayerDefinition::isLazy ( ) const
inline

Returns the lazy mode.

Returns
true if the loading is delayed, false otherwise.
See also
setLazy()
Since
QGIS 3.2

Definition at line 151 of file qgsvirtuallayerdefinition.h.

◆ query()

QString QgsVirtualLayerDefinition::query ( ) const
inline

Gets the SQL query.

Definition at line 121 of file qgsvirtuallayerdefinition.h.

◆ setFields()

void QgsVirtualLayerDefinition::setFields ( const QgsFields fields)
inline

Sets field definitions.

Definition at line 175 of file qgsvirtuallayerdefinition.h.

◆ setFilePath()

void QgsVirtualLayerDefinition::setFilePath ( const QString &  filePath)
inline

Sets the file path.

Definition at line 128 of file qgsvirtuallayerdefinition.h.

◆ setGeometryField()

void QgsVirtualLayerDefinition::setGeometryField ( const QString &  geometryField)
inline

Sets the name of the geometry field.

Definition at line 156 of file qgsvirtuallayerdefinition.h.

◆ setGeometrySrid()

void QgsVirtualLayerDefinition::setGeometrySrid ( long  srid)
inline

Sets the SRID of the geometry.

Definition at line 170 of file qgsvirtuallayerdefinition.h.

◆ setGeometryWkbType()

void QgsVirtualLayerDefinition::setGeometryWkbType ( Qgis::WkbType  t)
inline

Sets the type of the geometry.

Definition at line 165 of file qgsvirtuallayerdefinition.h.

◆ setLazy()

void QgsVirtualLayerDefinition::setLazy ( bool  lazy)
inline

Sets the lazy mode.

If lazy is true, then the loading is delayed until an explicit reloading of the layer.

Parameters
lazytrue to delay the loading, false otherwise
See also
QgsDataProvider::reloadData()
isLazy()
Since
QGIS 3.2

Definition at line 143 of file qgsvirtuallayerdefinition.h.

◆ setQuery()

void QgsVirtualLayerDefinition::setQuery ( const QString &  query)
inline

Sets the SQL query.

Definition at line 123 of file qgsvirtuallayerdefinition.h.

◆ setSubsetString()

void QgsVirtualLayerDefinition::setSubsetString ( const QString &  subsetString)

Sets the subsetString.

Since
QGIS 3.16

Definition at line 293 of file qgsvirtuallayerdefinition.cpp.

◆ setUid()

void QgsVirtualLayerDefinition::setUid ( const QString &  uid)
inline

Sets the name of the field with unique identifiers.

Definition at line 133 of file qgsvirtuallayerdefinition.h.

◆ sourceLayers()

const QgsVirtualLayerDefinition::SourceLayers& QgsVirtualLayerDefinition::sourceLayers ( ) const
inline

Gets access to the source layers.

Definition at line 118 of file qgsvirtuallayerdefinition.h.

◆ subsetString()

QString QgsVirtualLayerDefinition::subsetString ( ) const

Returns the subset string.

Since
QGIS 3.16

Definition at line 288 of file qgsvirtuallayerdefinition.cpp.

◆ toString()

QString QgsVirtualLayerDefinition::toString ( ) const

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

Definition at line 247 of file qgsvirtuallayerdefinition.cpp.

◆ toUrl()

QUrl QgsVirtualLayerDefinition::toUrl ( ) const

Convert the definition into a QUrl.

Definition at line 176 of file qgsvirtuallayerdefinition.cpp.

◆ uid()

QString QgsVirtualLayerDefinition::uid ( ) const
inline

Gets the name of the field with unique identifiers.

Definition at line 131 of file qgsvirtuallayerdefinition.h.


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