def processAlgorithm(self, parameters, context, feedback):
"""
Here is where the processing itself takes place.
"""
layerHandler = LayerHandler()
inputLyr = self.parameterAsVectorLayer(parameters, self.INPUT, context)
if inputLyr is None:
raise QgsProcessingException(
self.invalidSourceError(parameters, self.INPUT))
outputLyr = self.parameterAsVectorLayer(parameters, self.OUTPUT,
context)
if outputLyr is None:
raise QgsProcessingException(
self.invalidSourceError(parameters, self.OUTPUT))
if inputLyr == outputLyr:
raise QgsProcessingException(
self.tr('Input must be different from output!'))
inputExpression = self.parameterAsExpression(
parameters, self.INPUT_FILTER_EXPRESSION, context)
filterLyr = self.parameterAsVectorLayer(parameters, self.FILTER_LAYER,
context)
behavior = self.parameterAsEnum(parameters, self.BEHAVIOR, context)
prepairedLyr = layerHandler.prepareConversion(
inputLyr=inputLyr,
context=context,
inputExpression=inputExpression,
filterLyr=filterLyr,
behavior=behavior,
feedback=feedback)
return {self.INPUT: inputLyr}
def prepareInputLayers(self,
inputLayers,
stepConversionMap,
context=None,
feedback=None):
"""
Prepare layers for a translation unit (step) to be executed (e.g. applies filters).
:param inputLayers: (dict) a map from layer name to each vector layer contained by the
input datasource.
:param stepConversionMap: (dict) conversion map generated by Datasource Conversion tool
for a conversion step.
:param context: (QgsProcessingContext) environment parameters in which processing tools are used.
:param feedback: (QgsProcessingMultiStepFeedback) QGIS tool for progress tracking.
:return: (dict) map of layers to have its features mapped to output format.
"""
lh = LayerHandler()
context = context if context is not None else QgsProcessingContext()
layerFilters = stepConversionMap["filter"]["layer_filter"]
spatialFilters = stepConversionMap["filter"]["spatial_filter"]
# in case a selection of layers was made, only chosen layers should be translated
inputLayers = inputLayers if layerFilters == {} else {
layer: inputLayers[layer]
for layer in layerFilters
}
multiStepFeedback = QgsProcessingMultiStepFeedback(
len(inputLayers), feedback)
if spatialFilters:
# spatial filtering behaviour is set based on the modes defined in convertLayer2LayerAlgorithm
behaviour = self.getSpatialFilterBehaviour(
spatialFilters["predicate"] if "predicate" in
spatialFilters else None)
spatialFilterlLayer = self.prepareSpatialFilterLayer(
spatialFilters, context)
else:
behaviour = None
spatialFilters = None
preparedLayers = dict()
currentStep = 0
for layer, vl in inputLayers.items():
if feedback is not None:
multiStepFeedback.setCurrentStep(currentStep)
if multiStepFeedback.isCanceled():
break
currentStep += 1
translatedLayer = lh.prepareConversion(
inputLyr=vl,
context=context,
inputExpression=layerFilters[layer]["expression"]
if layer in layerFilters else None,
filterLyr=spatialFilterlLayer,
behavior=behaviour,
conversionMap=stepConversionMap,
feedback=multiStepFeedback if feedback is not None else None)
if translatedLayer.featureCount() > 0:
preparedLayers[layer] = translatedLayer
return preparedLayers
