27 mWidgetContext = context;
32 return mWidgetContext;
42 mContextGenerator = generator;
47 return QgsProcessingGuiUtils::createExpressionContext( mContextGenerator, mWidgetContext, mAlgorithm,
nullptr );
Expression contexts are used to encapsulate the parameters around which a QgsExpression should be eva...
Abstract base class for processing algorithms.
An interface for objects which can create Processing contexts.
Contains settings which reflect the context in which a Processing parameter widget is shown,...
As part of the API refactoring and improvements which landed in the Processing API was substantially reworked from the x version This was done in order to allow much of the underlying Processing framework to be ported into allowing algorithms to be written in pure substantial changes are required in order to port existing x Processing algorithms for QGIS x The most significant changes are outlined not GeoAlgorithm For algorithms which operate on features one by consider subclassing the QgsProcessingFeatureBasedAlgorithm class This class allows much of the boilerplate code for looping over features from a vector layer to be bypassed and instead requires implementation of a processFeature method Ensure that your algorithm(or algorithm 's parent class) implements the new pure virtual createInstance(self) call