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.

defaultGuiValueFromSetting

Default gui value for an algorithm parameter from settings

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.

See also

setCreateByDefault()

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

defaultGuiValueFromSetting(self) → Any¶

Default gui value for an algorithm parameter from settings

Returns:: default value from settings or invalid QVariant if there is no default value defined in the settings

New in version 3.34.

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

Parameters:: map (Dict[str) –
Return type:: bool

generateTemporaryDestination(self, context: QgsProcessingContext = None) → 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.

Parameters:: context (QgsProcessingContext = None) –
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:

value (Any) – value to test
context (QgsProcessingContext) – Processing context

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.

See also

createByDefault()