Base class for all parameter definitions which represent file or layer destinations, e.g. More...

#include <qgsprocessingparameters.h>

Inheritance diagram for QgsProcessingDestinationParameter:

[legend]

Public Member Functions
	QgsProcessingDestinationParameter (const QString &name, const QString &description=QString(), const QVariant &defaultValue=QVariant(), bool optional=false, bool createByDefault=true)
	Constructor for QgsProcessingDestinationParameter.

QString	asPythonString (QgsProcessing::PythonOutputType outputType=QgsProcessing::PythonOutputType::PythonQgsProcessingAlgorithmSubclass) const override
	Returns the parameter definition as a Python command which can be used within a Python Processing script.

bool	createByDefault () const
	Returns `true` if the destination should be created by default.

QString	createFileFilter () const override
	This method needs to be reimplemented in all classes which implement this interface and return a file filter.

virtual QString	defaultFileExtension () const =0
	Returns the default file extension for destination file paths associated with this parameter.

bool	fromVariantMap (const QVariantMap &map) override
	Restores this parameter to a QVariantMap.

virtual QString	generateTemporaryDestination (const QgsProcessingContext *context=nullptr) const
	Generates a temporary destination value for this parameter.

bool	isDestination () const override
	Returns `true` if this parameter represents a file or layer destination, e.g.

virtual bool	isSupportedOutputValue (const QVariant &value, QgsProcessingContext &context, QString &error) const
	Tests whether a value is a supported value for this parameter.

void	setCreateByDefault (bool createByDefault)
	Sets whether the destination should be created by default.

void	setSupportsNonFileBasedOutput (bool supportsNonFileBasedOutput)
	Sets whether the destination parameter supports non filed-based outputs, such as memory layers or direct database outputs.

bool	supportsNonFileBasedOutput () const
	Returns `true` if the destination parameter supports non filed-based outputs, such as memory layers or direct database outputs.

virtual QgsProcessingOutputDefinition *	toOutputDefinition () const =0
	Returns a new QgsProcessingOutputDefinition corresponding to the definition of the destination parameter.

QVariantMap	toVariantMap () const override
	Saves this parameter to a QVariantMap.

Public Member Functions inherited from QgsProcessingParameterDefinition
	QgsProcessingParameterDefinition (const QString &name, const QString &description=QString(), const QVariant &defaultValue=QVariant(), bool optional=false, const QString &help=QString())
	Constructor for QgsProcessingParameterDefinition.

virtual	~QgsProcessingParameterDefinition ()=default

QStringList	additionalExpressionContextVariables () const
	Returns a list of additional expression context variables which are available for use when evaluating this parameter.

QgsProcessingAlgorithm *	algorithm () const
	Returns a pointer to the algorithm which owns this parameter.

virtual QString	asScriptCode () const
	Returns the parameter definition encoded in a string which can be used within a Processing script.

virtual bool	checkValueIsAcceptable (const QVariant &input, QgsProcessingContext *context=nullptr) const
	Checks whether the specified input value is acceptable for the parameter.

virtual QgsProcessingParameterDefinition *	clone () const =0
	Creates a clone of the parameter definition.

QVariant	defaultValue () const
	Returns the default value for the parameter.

QVariant	defaultValueForGui () const
	Returns the default value to use for the parameter in a GUI.

virtual QStringList	dependsOnOtherParameters () const
	Returns a list of other parameter names on which this parameter is dependent (e.g.

QString	description () const
	Returns the description for the parameter.

QString	dynamicLayerParameterName () const
	Returns the name of the parameter for a layer linked to a dynamic parameter, or an empty string if this is not set.

QgsPropertyDefinition	dynamicPropertyDefinition () const
	Returns the property definition for dynamic properties.

Qgis::ProcessingParameterFlags	flags () const
	Returns any flags associated with the parameter.

QVariant	guiDefaultValueOverride () const
	Returns the default value to use in the GUI for the parameter.

QString	help () const
	Returns the help for the parameter.

bool	isDynamic () const
	Returns `true` if the parameter supports is dynamic, and can support data-defined values (i.e.

QVariantMap &	metadata ()
	Returns the parameter's freeform metadata.

QVariantMap	metadata () const
	Returns the parameter's freeform metadata.

QString	name () const
	Returns the name of the parameter.

QgsProcessingProvider *	provider () const
	Returns a pointer to the provider for the algorithm which owns this parameter.

void	setAdditionalExpressionContextVariables (const QStringList &variables)
	Sets a list of additional expression context variables which are available for use when evaluating this parameter.

void	setDefaultValue (const QVariant &value)
	Sets the default value for the parameter.

void	setDescription (const QString &description)
	Sets the description for the parameter.

void	setDynamicLayerParameterName (const QString &name)
	Sets the name for the parameter for a layer linked to a dynamic parameter, or an empty string if this is not set.

void	setDynamicPropertyDefinition (const QgsPropertyDefinition &definition)
	Sets the property definition for dynamic properties.

void	setFlags (Qgis::ProcessingParameterFlags flags)
	Sets the flags associated with the parameter.

void	setGuiDefaultValueOverride (const QVariant &value)
	Sets the default value to use for the parameter in GUI widgets.

void	setHelp (const QString &help)
	Sets the help for the parameter.

void	setIsDynamic (bool dynamic)
	Sets whether the parameter is dynamic, and can support data-defined values (i.e.

void	setMetadata (const QVariantMap &metadata)
	Sets the parameter's freeform metadata.

void	setName (const QString &name)
	Sets the name of the parameter.

virtual QString	toolTip () const
	Returns a formatted tooltip for use with the parameter, which gives helpful information like parameter description, ID, and extra content like default values (depending on parameter type).

virtual QString	type () const =0
	Unique parameter type name.

virtual QVariant	valueAsJsonObject (const QVariant &value, QgsProcessingContext &context) const
	Returns a version of the parameter input value, which is suitable for use in a JSON object.

virtual QString	valueAsPythonComment (const QVariant &value, QgsProcessingContext &context) const
	Returns a Python comment explaining a parameter value, or an empty string if no comment is required.

virtual QString	valueAsPythonString (const QVariant &value, QgsProcessingContext &context) const
	Returns a string version of the parameter input value, which is suitable for use as an input parameter value when running an algorithm directly from a Python command.

virtual QString	valueAsString (const QVariant &value, QgsProcessingContext &context, bool &ok) const
	Returns a string version of the parameter input value (if possible).

virtual QStringList	valueAsStringList (const QVariant &value, QgsProcessingContext &context, bool &ok) const
	Returns a string list version of the parameter input value (if possible).

Public Member Functions inherited from QgsFileFilterGenerator
virtual	~QgsFileFilterGenerator ()=default

Protected Member Functions
QgsProcessingProvider *	originalProvider () const
	Original (source) provider which this parameter has been derived from.

Protected Member Functions inherited from QgsProcessingParameterDefinition
QVariant	defaultGuiValueFromSetting () const
	Default gui value for an algorithm parameter from settings.

QVariant	valueAsJsonObjectPrivate (const QVariant &value, QgsProcessingContext &context, ValueAsStringFlags flags) const
	Internal method for evaluating values as JSON objects.

QString	valueAsStringPrivate (const QVariant &value, QgsProcessingContext &context, bool &ok, ValueAsStringFlags flags) const
	Internal method for evaluating values as string.

Friends
class	QgsProcessingModelAlgorithm

class	TestQgsProcessing

class	TestQgsProcessingModelAlgorithm

Additional Inherited Members
Public Types inherited from QgsProcessingParameterDefinition
enum class	ValueAsStringFlag : int { AllowMapLayerValues = 1 << 0 }
	Flags for passing to the valueAsStringPrivate() method. More...

typedef QFlags< ValueAsStringFlag >	ValueAsStringFlags

Protected Attributes inherited from QgsProcessingParameterDefinition
QStringList	mAdditionalExpressionVariables
	Additional expression context variables exposed for use by this parameter.

QgsProcessingAlgorithm *	mAlgorithm = nullptr
	Pointer to algorithm which owns this parameter.

QVariant	mDefault
	Default value for parameter.

QString	mDescription
	Parameter description.

QString	mDynamicLayerParameterName
	Linked vector layer parameter name for dynamic properties.

Qgis::ProcessingParameterFlags	mFlags
	Parameter flags.

QVariant	mGuiDefault
	Default value for parameter in GUI.

QString	mHelp
	Parameter help.

bool	mIsDynamic = false
	True for dynamic parameters, which can have data-defined (QgsProperty) based values.

QVariantMap	mMetadata
	Freeform metadata for parameter. Mostly used by widget wrappers to customize their appearance and behavior.

QString	mName
	Parameter name.

QgsPropertyDefinition	mPropertyDefinition
	Data defined property definition.

Detailed Description

Base class for all parameter definitions which represent file or layer destinations, e.g.

parameters which are used for the destination for layers output by an algorithm.

Definition at line 3326 of file qgsprocessingparameters.h.

Constructor & Destructor Documentation

◆ QgsProcessingDestinationParameter()

QgsProcessingDestinationParameter::QgsProcessingDestinationParameter	(	const QString &	name,
		const QString &	description = `QString()`,
		const QVariant &	defaultValue = `QVariant()`,
		bool	optional = `false`,
		bool	createByDefault = `true`
	)

Constructor for QgsProcessingDestinationParameter.

If createByDefault is false and the parameter is optional, then the destination output will not be created by default.

Definition at line 7095 of file qgsprocessingparameters.cpp.

Member Function Documentation

◆ asPythonString()

QString QgsProcessingDestinationParameter::asPythonString ( QgsProcessing::PythonOutputType outputType = QgsProcessing::PythonOutputType::PythonQgsProcessingAlgorithmSubclass ) const

overridevirtual

Returns the parameter definition as a Python command which can be used within a Python Processing script.

The outputType argument specifies the desired output format for the Python string, i.e. the intended end use of the generated Python code.

Since: QGIS 3.6

Reimplemented from QgsProcessingParameterDefinition.

Reimplemented in QgsProcessingParameterFeatureSink, QgsProcessingParameterVectorDestination, and QgsProcessingParameterFileDestination.

Definition at line 7118 of file qgsprocessingparameters.cpp.

◆ createByDefault()

bool QgsProcessingDestinationParameter::createByDefault ( ) const

Returns true if the destination should be created by default.

For optional parameters, a return value of false indicates that the destination should not be created by default.

See also: setCreateByDefault()

Definition at line 7178 of file qgsprocessingparameters.cpp.

◆ createFileFilter()

QString QgsProcessingDestinationParameter::createFileFilter ( ) const

overridevirtual

This method needs to be reimplemented in all classes which implement this interface and return a file filter.

Implements QgsFileFilterGenerator.

Reimplemented in QgsProcessingParameterFeatureSink, QgsProcessingParameterVectorDestination, QgsProcessingParameterRasterDestination, QgsProcessingParameterFileDestination, QgsProcessingParameterPointCloudDestination, and QgsProcessingParameterVectorTileDestination.

Definition at line 7145 of file qgsprocessingparameters.cpp.

◆ defaultFileExtension()

virtual QString QgsProcessingDestinationParameter::defaultFileExtension ( ) const

pure virtual

Returns the default file extension for destination file paths associated with this parameter.

Implemented in QgsProcessingParameterFeatureSink, QgsProcessingParameterVectorDestination, QgsProcessingParameterRasterDestination, QgsProcessingParameterFileDestination, QgsProcessingParameterFolderDestination, QgsProcessingParameterPointCloudDestination, and QgsProcessingParameterVectorTileDestination.

◆ fromVariantMap()

bool QgsProcessingDestinationParameter::fromVariantMap ( const QVariantMap & map )

overridevirtual

Restores this parameter to a QVariantMap.

Subclasses should ensure that they call the base class method.

See also: toVariantMap()

Reimplemented from QgsProcessingParameterDefinition.

Reimplemented in QgsProcessingParameterFeatureSink, QgsProcessingParameterVectorDestination, and QgsProcessingParameterFileDestination.

Definition at line 7110 of file qgsprocessingparameters.cpp.

◆ generateTemporaryDestination()

QString QgsProcessingDestinationParameter::generateTemporaryDestination ( const QgsProcessingContext * context = nullptr ) const

virtual

Generates a temporary destination value for this parameter.

The returned value will be a file path or QGIS data provider URI suitable for temporary storage of created layers and files.

Reimplemented in QgsProcessingParameterFeatureSink.

Definition at line 7150 of file qgsprocessingparameters.cpp.

◆ isDestination()

bool QgsProcessingDestinationParameter::isDestination ( ) const

inlineoverridevirtual

Returns true if this parameter represents a file or layer destination, e.g.

parameters which are used for the destination for layers output by an algorithm will return true.

Reimplemented from QgsProcessingParameterDefinition.

Definition at line 3339 of file qgsprocessingparameters.h.

◆ isSupportedOutputValue()

bool QgsProcessingDestinationParameter::isSupportedOutputValue	(	const QVariant &	value,
		QgsProcessingContext &	context,
		QString &	error
	)		const

virtual

Tests whether a value is a supported value for this parameter.

Will return false when a value with an unsupported file extension is specified. The default implementation calls QgsProcessingProvider::isSupportedOutputValue() to test compatibility.

Parameters

value	value to test
context	Processing context
error	will be set to a descriptive error string

Returns: true if value is supported.

Since: QGIS 3.14

Definition at line 7168 of file qgsprocessingparameters.cpp.

◆ originalProvider()

QgsProcessingProvider * QgsProcessingDestinationParameter::originalProvider ( ) const

inlineprotected

Original (source) provider which this parameter has been derived from.

In the case of destination parameters which are part of model algorithms, this will reflect the child algorithm's provider which actually generates the parameter, as opposed to the provider which this parameter belongs to (i.e. the model provider)