A registry / canonical manager of data providers. More...

#include <qgsproviderregistry.h>

Public Types
typedef std::map< QString, QgsProviderMetadata * >	Providers
	Type for data provider metadata associative container. More...

enum	WidgetMode { None, Embedded, Manager }
	Different ways a source select dialog can be used. More...

Public Member Functions
virtual	~QgsProviderRegistry ()

bool	createDb (const QString &providerKey, const QString &dbPath, QString &errCause)
	Creates database by the provider on the path. More...

QgsVectorLayerExporter::ExportError	createEmptyLayer (const QString &providerKey, const QString &uri, const QgsFields &fields, QgsWkbTypes::Type wkbType, const QgsCoordinateReferenceSystem &srs, bool overwrite, QMap< int, int > &oldToNewAttrIdxMap, QString &errorMessage, const QMap< QString, QVariant > *options)
	Creates new empty vector layer. More...

QgsDataProvider *	createProvider (const QString &providerKey, const QString &dataSource, const QgsDataProvider::ProviderOptions &options=QgsDataProvider::ProviderOptions(), QgsDataProvider::ReadFlags flags=QgsDataProvider::ReadFlags())
	Creates a new instance of a provider. More...

Q_DECL_DEPRECATED QLibrary *	createProviderLibrary (const QString &providerKey) const
	Returns a new QLibrary for the specified providerKey. More...

virtual QgsRasterDataProvider *	createRasterDataProvider (const QString &providerKey, const QString &uri, const QString &format, int nBands, Qgis::DataType type, int width, int height, double *geoTransform, const QgsCoordinateReferenceSystem &crs, const QStringList &createOptions=QStringList())
	Creates new instance of raster data provider. More...

Q_DECL_DEPRECATED QWidget *	createSelectionWidget (const QString &providerKey, QWidget *parent=nullptr, Qt::WindowFlags fl=Qt::WindowFlags(), QgsProviderRegistry::WidgetMode widgetMode=QgsProviderRegistry::WidgetMode::None)
	Returns a new widget for selecting layers from a provider. More...

QgsTransaction *	createTransaction (const QString &providerKey, const QString &connString)
	Returns new instance of transaction. More...

virtual QString	databaseDrivers () const
	Returns a string containing the available database drivers. More...

QList< QgsDataItemProvider * >	dataItemProviders (const QString &providerKey) const
	Returns list of data item providers of the provider. More...

QVariantMap	decodeUri (const QString &providerKey, const QString &uri)
	Breaks a provider data source URI into its component paths (e.g. More...

bool	deleteStyleById (const QString &providerKey, const QString &uri, QString styleId, QString &errCause)
	Deletes a layer style defined by styleId. More...

virtual QString	directoryDrivers () const
	Returns a string containing the available directory drivers. More...

QString	encodeUri (const QString &providerKey, const QVariantMap &parts)
	Reassembles a provider data source URI from its component paths (e.g. More...

virtual QString	fileMeshDatasetFilters () const
	Returns mesh's dataset file filter string. More...

virtual QString	fileMeshFilters () const
	Returns mesh file filter string. More...

virtual QString	fileRasterFilters () const
	Returns raster file filter string. More...

virtual QString	fileVectorFilters () const
	Returns vector file filter string. More...

Q_DECL_DEPRECATED QFunctionPointer	function (const QString &providerKey, const QString &functionName)
	Gets pointer to provider function. More...

QString	getStyleById (const QString &providerKey, const QString &uri, QString styleId, QString &errCause)
	Gets a layer style defined by styleId. More...

Q_DECL_DEPRECATED QString	library (const QString &providerKey) const
	Returns path for the library of the provider. More...

QDir	libraryDirectory () const
	Returns the library directory where plugins are found. More...

int	listStyles (const QString &providerKey, const QString &uri, QStringList &ids, QStringList &names, QStringList &descriptions, QString &errCause)
	Lists stored layer styles in the provider defined by providerKey and uri. More...

QString	loadStyle (const QString &providerKey, const QString &uri, QString &errCause)
	Loads a layer style defined by uri. More...

QString	pluginList (bool asHtml=false) const
	Returns list of provider plugins found. More...

virtual QString	protocolDrivers () const
	Returns a string containing the available protocol drivers. More...

Q_DECL_DEPRECATED int	providerCapabilities (const QString &providerKey) const
	Returns the provider capabilities. More...

QStringList	providerList () const
	Returns list of available providers by their keys. More...

QgsProviderMetadata *	providerMetadata (const QString &providerKey) const
	Returns metadata of the provider or `nullptr` if not found. More...

QList< QPair< QString, QString > >	pyramidResamplingMethods (const QString &providerKey)
	Returns list of raster pyramid resampling methods. More...

Q_DECL_DEPRECATED void	registerGuis (QWidget *widget)

bool	registerProvider (QgsProviderMetadata *providerMetadata)
	register a new vector data provider from its providerMetadata More...

bool	saveStyle (const QString &providerKey, const QString &uri, const QString &qmlStyle, const QString &sldStyle, const QString &styleName, const QString &styleDescription, const QString &uiFileContent, bool useAsDefault, QString &errCause)
	Saves a layer style to provider. More...

void	setLibraryDirectory (const QDir &path)
	Sets library directory where to search for plugins. More...

Static Public Member Functions
static QgsProviderRegistry *	instance (const QString &pluginPath=QString())
	Means of accessing canonical single instance. More...

Friends
class	QgsApplication

Detailed Description

A registry / canonical manager of data providers.

This is a Singleton class that manages data provider access.

Providers can be either loaded via libraries or native providers that are included in the core QGIS installation and accessed through function pointers.

Loaded providers may be restricted using QGIS_PROVIDER_FILE environment variable. QGIS_PROVIDER_FILE is regexp pattern applied to provider file name (not provider key). For example, if the variable is set to gdal|ogr|postgres it will load only providers gdal, ogr and postgres.

Definition at line 54 of file qgsproviderregistry.h.

Member Typedef Documentation

◆ Providers

typedef std::map<QString, QgsProviderMetadata *> QgsProviderRegistry::Providers

Type for data provider metadata associative container.

Definition at line 364 of file qgsproviderregistry.h.

Member Enumeration Documentation

◆ WidgetMode

enum QgsProviderRegistry::WidgetMode

Different ways a source select dialog can be used.

Enumerator

None

Basic mode when the widget is used as a standalone dialog.

Originally used as GUI for individual "Add XXX layer" buttons in the main window. Likely not used in live code anymore.

Embedded

Used for the data source manager dialog where the widget is embedded as the main content for a particular tab.

Manager

Used by data items for QgsDataItem::paramWidget().

Originally used by QGIS Browser, but does not seem to be in live code anymore. The mode was meant to avoid some actions to keep the browser interface simple (supposedly).

Definition at line 64 of file qgsproviderregistry.h.

Constructor & Destructor Documentation

◆ ~QgsProviderRegistry()

QgsProviderRegistry::~QgsProviderRegistry ( )

virtual

Definition at line 330 of file qgsproviderregistry.cpp.

Member Function Documentation

◆ createDb()

bool QgsProviderRegistry::createDb	(	const QString &	providerKey,
		const QString &	dbPath,
		QString &	errCause
	)

Creates database by the provider on the path.

Since: QGIS 3.10

Definition at line 577 of file qgsproviderregistry.cpp.

◆ createEmptyLayer()

QgsVectorLayerExporter::ExportError QgsProviderRegistry::createEmptyLayer	(	const QString &	providerKey,
		const QString &	uri,
		const QgsFields &	fields,
		QgsWkbTypes::Type	wkbType,
		const QgsCoordinateReferenceSystem &	srs,
		bool	overwrite,
		QMap< int, int > &	oldToNewAttrIdxMap,
		QString &	errorMessage,
		const QMap< QString, QVariant > *	options
	)

Creates new empty vector layer.

Note: not available in Python bindings

Since: QGIS 3.10

Definition at line 451 of file qgsproviderregistry.cpp.

◆ createProvider()

QgsDataProvider * QgsProviderRegistry::createProvider	(	const QString &	providerKey,
		const QString &	dataSource,
		const QgsDataProvider::ProviderOptions &	options = `QgsDataProvider::ProviderOptions()`,
		QgsDataProvider::ReadFlags	flags = `QgsDataProvider::ReadFlags()`
	)

Creates a new instance of a provider.

Parameters

providerKey	identifier of the provider
dataSource	string containing data source for the provider
options	provider options
flags	provider flags since QGIS 3.16

Returns: new instance of provider or nullptr on error

See also: createRasterDataProvider()

Definition at line 404 of file qgsproviderregistry.cpp.

◆ createProviderLibrary()

QLibrary * QgsProviderRegistry::createProviderLibrary ( const QString & providerKey ) const

Returns a new QLibrary for the specified providerKey.

Ownership of the returned object is transferred to the caller and the caller is responsible for deleting it.

If the provider uses direct provider function pointers instead of a library nullptr will be returned.

Deprecated:: QGIS 3.10 - providers may not need to be loaded from a library

Definition at line 633 of file qgsproviderregistry.cpp.

◆ createRasterDataProvider()

QgsRasterDataProvider * QgsProviderRegistry::createRasterDataProvider	(	const QString &	providerKey,
		const QString &	uri,
		const QString &	format,
		int	nBands,
		Qgis::DataType	type,
		int	width,
		int	height,
		double *	geoTransform,
		const QgsCoordinateReferenceSystem &	crs,
		const QStringList &	createOptions = `QStringList()`
	)

virtual

Creates new instance of raster data provider.

See also: createProvider()

Since: QGIS 3.10

Definition at line 474 of file qgsproviderregistry.cpp.

◆ createSelectionWidget()

QWidget * QgsProviderRegistry::createSelectionWidget	(	const QString &	providerKey,
		QWidget *	parent = `nullptr`,
		Qt::WindowFlags	fl = `Qt::WindowFlags()`,
		QgsProviderRegistry::WidgetMode	widgetMode = `QgsProviderRegistry::WidgetMode::None`
	)

Returns a new widget for selecting layers from a provider.

Either the parent widget must be set or the caller becomes responsible for deleting the returned widget.

Deprecated:: QGIS 3.10 - use QgsGui::sourceSelectProviderRegistry()->createDataSourceWidget() instead

Definition at line 598 of file qgsproviderregistry.cpp.

◆ createTransaction()

QgsTransaction * QgsProviderRegistry::createTransaction	(	const QString &	providerKey,
		const QString &	connString
	)

Returns new instance of transaction.

Ownership is transferred to the caller

Since: QGIS 3.10

Definition at line 589 of file qgsproviderregistry.cpp.

◆ databaseDrivers()

QString QgsProviderRegistry::databaseDrivers ( ) const

virtual

Returns a string containing the available database drivers.

Definition at line 699 of file qgsproviderregistry.cpp.

◆ dataItemProviders()

QList< QgsDataItemProvider * > QgsProviderRegistry::dataItemProviders ( const QString & providerKey ) const

Returns list of data item providers of the provider.

Note: Ownership of created data item providers is passed to the caller.

Since: QGIS 3.10

Definition at line 495 of file qgsproviderregistry.cpp.

◆ decodeUri()

QVariantMap QgsProviderRegistry::decodeUri	(	const QString &	providerKey,
		const QString &	uri
	)

Breaks a provider data source URI into its component paths (e.g.

file path, layer name).

Parameters

providerKey	identifier of the provider
uri	uri string

Returns: map containing components. Standard components include "path", "layerName", "url".

Note: this function may not be supported by all providers, an empty map will be returned in such case

Since: QGIS 3.4

Definition at line 433 of file qgsproviderregistry.cpp.

◆ deleteStyleById()

bool QgsProviderRegistry::deleteStyleById	(	const QString &	providerKey,
		const QString &	uri,
		QString	styleId,
		QString &	errCause
	)

Deletes a layer style defined by styleId.

Since: QGIS 3.10

Definition at line 534 of file qgsproviderregistry.cpp.

◆ directoryDrivers()

QString QgsProviderRegistry::directoryDrivers ( ) const

virtual

Returns a string containing the available directory drivers.

Definition at line 704 of file qgsproviderregistry.cpp.

◆ encodeUri()

QString QgsProviderRegistry::encodeUri	(	const QString &	providerKey,
		const QVariantMap &	parts
	)

Reassembles a provider data source URI from its component paths (e.g.

file path, layer name).

Parameters

providerKey	identifier of the provider
parts	parts as returned by decodeUri

Returns: datasource uri string

Note: this function may not be supported by all providers, an empty string will be returned in such case

See also: decodeUri()

Since: QGIS 3.12

Definition at line 442 of file qgsproviderregistry.cpp.

◆ fileMeshDatasetFilters()

QString QgsProviderRegistry::fileMeshDatasetFilters ( ) const

virtual

Returns mesh's dataset file filter string.

Returns a string suitable for a QFileDialog of mesh datasets file formats supported by all data providers.

This walks through all data providers appending calls to their fileMeshFilters to a string, which is then returned.

See also: fileMeshFilters()

Since: QGIS 3.6

Definition at line 694 of file qgsproviderregistry.cpp.

◆ fileMeshFilters()

QString QgsProviderRegistry::fileMeshFilters ( ) const

virtual

Returns mesh file filter string.

Returns a string suitable for a QFileDialog of mesh file formats supported by all data providers.

This walks through all data providers appending calls to their fileMeshFilters to a string, which is then returned.

See also: fileMeshDatasetFilters()

Since: QGIS 3.6

Definition at line 689 of file qgsproviderregistry.cpp.

◆ fileRasterFilters()

QString QgsProviderRegistry::fileRasterFilters ( ) const

virtual

Returns raster file filter string.

Returns a string suitable for a QFileDialog of raster file formats supported by all data providers.

This walks through all data providers appending calls to their buildSupportedRasterFileFilter to a string, which is then returned.

Note: This replaces QgsRasterLayer::buildSupportedRasterFileFilter()

Definition at line 684 of file qgsproviderregistry.cpp.

◆ fileVectorFilters()

QString QgsProviderRegistry::fileVectorFilters ( ) const

virtual

Returns vector file filter string.

Returns a string suitable for a QFileDialog of vector file formats supported by all data providers.

This walks through all data providers appending calls to their fileVectorFilters to a string, which is then returned.

Note

It'd be nice to eventually be raster/vector neutral.

Definition at line 679 of file qgsproviderregistry.cpp.

◆ function()

QFunctionPointer QgsProviderRegistry::function	(	const QString &	providerKey,
		const QString &	functionName
	)

Gets pointer to provider function.

Parameters

providerKey	identifier of the provider
functionName	name of function

Returns: pointer to function or nullptr on error. If the provider uses direct provider function pointers instead of a library nullptr will be returned.

Deprecated:: QGIS 3.10 - any provider functionality should be accessed through QgsProviderMetadata

Definition at line 609 of file qgsproviderregistry.cpp.

◆ getStyleById()

QString QgsProviderRegistry::getStyleById	(	const QString &	providerKey,
		const QString &	uri,
		QString	styleId,
		QString &	errCause
	)

Gets a layer style defined by styleId.

Since: QGIS 3.10

Definition at line 519 of file qgsproviderregistry.cpp.

◆ instance()

QgsProviderRegistry * QgsProviderRegistry::instance ( const QString & pluginPath = QString() )

static

Means of accessing canonical single instance.

Definition at line 48 of file qgsproviderregistry.cpp.

◆ library()

QString QgsProviderRegistry::library ( const QString & providerKey ) const

Returns path for the library of the provider.

If the provider uses direct provider function pointers instead of a library an empty string will be returned.

Deprecated:: QGIS 3.10 - providers may not need to be loaded from a library (empty string returned)

Definition at line 337 of file qgsproviderregistry.cpp.

◆ libraryDirectory()

QDir QgsProviderRegistry::libraryDirectory ( ) const

Returns the library directory where plugins are found.

Definition at line 391 of file qgsproviderregistry.cpp.

◆ listStyles()

int QgsProviderRegistry::listStyles	(	const QString &	providerKey,
		const QString &	uri,
		QStringList &	ids,
		QStringList &	names,
		QStringList &	descriptions,
		QString &	errCause
	)

Lists stored layer styles in the provider defined by providerKey and uri.

Returns: -1 if not implemented by provider, otherwise number of styles stored

Since: QGIS 3.10

Definition at line 504 of file qgsproviderregistry.cpp.

◆ loadStyle()

QString QgsProviderRegistry::loadStyle	(	const QString &	providerKey,
		const QString &	uri,
		QString &	errCause
	)

Loads a layer style defined by uri.

Since: QGIS 3.10

Definition at line 564 of file qgsproviderregistry.cpp.

◆ pluginList()

QString QgsProviderRegistry::pluginList ( bool asHtml = false ) const

Returns list of provider plugins found.

Definition at line 351 of file qgsproviderregistry.cpp.

◆ protocolDrivers()

QString QgsProviderRegistry::protocolDrivers ( ) const

virtual

Returns a string containing the available protocol drivers.

Definition at line 709 of file qgsproviderregistry.cpp.

◆ providerCapabilities()

int QgsProviderRegistry::providerCapabilities ( const QString & providerKey ) const

Returns the provider capabilities.

Parameters

providerKey identifier of the provider

Since: QGIS 2.6

Deprecated:: QGIS 3.10 (use instead capabilities() method of individual data item provider)

Definition at line 421 of file qgsproviderregistry.cpp.

◆ providerList()

QStringList QgsProviderRegistry::providerList ( ) const

Returns list of available providers by their keys.

Definition at line 714 of file qgsproviderregistry.cpp.

◆ providerMetadata()

QgsProviderMetadata * QgsProviderRegistry::providerMetadata ( const QString & providerKey ) const

Returns metadata of the provider or nullptr if not found.

Definition at line 724 of file qgsproviderregistry.cpp.

◆ pyramidResamplingMethods()

QList< QPair< QString, QString > > QgsProviderRegistry::pyramidResamplingMethods ( const QString & providerKey )

Returns list of raster pyramid resampling methods.

Since: QGIS 3.10

Definition at line 486 of file qgsproviderregistry.cpp.

◆ registerGuis()

void QgsProviderRegistry::registerGuis ( QWidget * widget )

Deprecated:: since QGIS 3.10 - does nothing - use QgsGui::providerGuiRegistry()

Definition at line 653 of file qgsproviderregistry.cpp.

◆ registerProvider()

bool QgsProviderRegistry::registerProvider ( QgsProviderMetadata * providerMetadata )

register a new vector data provider from its providerMetadata

Returns: true on success, false if a provider with the same key was already registered

Note: ownership of the QgsProviderMetadata instance is transferred to the registry

Since: QGIS 3.2

Definition at line 658 of file qgsproviderregistry.cpp.

◆ saveStyle()

bool QgsProviderRegistry::saveStyle	(	const QString &	providerKey,
		const QString &	uri,
		const QString &	qmlStyle,
		const QString &	sldStyle,
		const QString &	styleName,
		const QString &	styleDescription,
		const QString &	uiFileContent,
		bool	useAsDefault,
		QString &	errCause
	)

Saves a layer style to provider.

Since: QGIS 3.10

Definition at line 548 of file qgsproviderregistry.cpp.

◆ setLibraryDirectory()

void QgsProviderRegistry::setLibraryDirectory ( const QDir & path )

Sets library directory where to search for plugins.

Definition at line 384 of file qgsproviderregistry.cpp.

Friends And Related Function Documentation

◆ QgsApplication

friend class QgsApplication

friend

Definition at line 437 of file qgsproviderregistry.h.

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

/build/qgis-3.16.0+99unstable/src/core/qgsproviderregistry.h
/build/qgis-3.16.0+99unstable/src/core/qgsproviderregistry.cpp

Public Types

Public Member Functions

Static Public Member Functions

Friends

Detailed Description

Member Typedef Documentation

◆ Providers

Member Enumeration Documentation

◆ WidgetMode

Constructor & Destructor Documentation

◆ ~QgsProviderRegistry()

Member Function Documentation

◆ createDb()

◆ createEmptyLayer()

◆ createProvider()

◆ createProviderLibrary()

◆ createRasterDataProvider()

◆ createSelectionWidget()

◆ createTransaction()

◆ databaseDrivers()

◆ dataItemProviders()

◆ decodeUri()

◆ deleteStyleById()

◆ directoryDrivers()

◆ encodeUri()

◆ fileMeshDatasetFilters()

◆ fileMeshFilters()

◆ fileRasterFilters()

◆ fileVectorFilters()

◆ function()

◆ getStyleById()

◆ instance()

◆ library()

◆ libraryDirectory()

◆ listStyles()

◆ loadStyle()

◆ pluginList()

◆ protocolDrivers()

◆ providerCapabilities()

◆ providerList()

◆ providerMetadata()

◆ pyramidResamplingMethods()

◆ registerGuis()

◆ registerProvider()

◆ saveStyle()

◆ setLibraryDirectory()

Friends And Related Function Documentation

◆ QgsApplication