Class: QgsProcessingDestinationParameter

class qgis.core.QgsProcessingDestinationParameter

Bases: QgsProcessingParameterDefinition, QgsFileFilterGenerator

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.

New in version 3.0.

QgsProcessingDestinationParameter(name: str, description: str = ‘’, defaultValue: Any = None, optional: bool = False, createByDefault: bool = True) Constructor for QgsProcessingDestinationParameter.

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

QgsProcessingDestinationParameter(QgsProcessingDestinationParameter)

Methods

asPythonString

param outputType

createByDefault

Returns True if the destination should be created by default.

createFileFilter

rtype

str

defaultFileExtension

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

fromVariantMap

param map

generateTemporaryDestination

Generates a temporary destination value for this parameter.

isDestination

rtype

bool

isSupportedOutputValue

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

originalProvider

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

setCreateByDefault

Sets whether the destination should be created by default.

setSupportsNonFileBasedOutput

Sets whether the destination parameter supports non filed-based outputs, such as memory layers or direct database outputs.

supportsNonFileBasedOutput

Returns True if the destination parameter supports non filed-based outputs, such as memory layers or direct database outputs.

toOutputDefinition

Returns a new QgsProcessingOutputDefinition corresponding to the definition of the destination parameter.

toVariantMap

rtype

Dict[str, Any]

asPythonString(self, outputType: QgsProcessing.PythonOutputType = QgsProcessing.PythonQgsProcessingAlgorithmSubclass)str
Parameters

outputType (QgsProcessing.PythonOutputType = QgsProcessing.PythonQgsProcessingAlgorithmSubclass) –

Return type

str

createByDefault(self)bool

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.

Return type

bool

createFileFilter(self)str
Return type

str

defaultFileExtension(self)str

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

Return type

str

fromVariantMap(self, map: Dict[str, Any])bool
Parameters

map (Dict[str) –

Return type

bool

generateTemporaryDestination(self)str

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.

Return type

str

isDestination(self)bool
Return type

bool

isSupportedOutputValue(self, value: Any, context: QgsProcessingContext)Tuple[bool, str]

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
Return type

Tuple[bool, str]

Returns

  • True if value is supported.

  • error: will be set to a descriptive error string

New in version 3.14.

originalProvider(self)QgsProcessingProvider

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)

New in version 3.2.

Return type

QgsProcessingProvider

setCreateByDefault(self, createByDefault: bool)

Sets whether the destination should be created by default. For optional parameters, a value of False indicates that the destination should not be created by default.

Parameters

createByDefault (bool) –

setSupportsNonFileBasedOutput(self, supportsNonFileBasedOutput: bool)

Sets whether the destination parameter supports non filed-based outputs, such as memory layers or direct database outputs.

Parameters

supportsNonFileBasedOutput (bool) –

supportsNonFileBasedOutput(self)bool

Returns True if the destination parameter supports non filed-based outputs, such as memory layers or direct database outputs.

Return type

bool

toOutputDefinition(self)QgsProcessingOutputDefinition

Returns a new QgsProcessingOutputDefinition corresponding to the definition of the destination parameter.

Return type

QgsProcessingOutputDefinition

toVariantMap(self)Dict[str, Any]
Return type

Dict[str, Any]