[processing] Set full context for QgsProcessingAlgorithmConfigurationWidget in modeler config dialogs

Author: nyalldawson

python/plugins/processing/modeler/ModelerParametersDialog.py

@@ -140,17 +140,21 @@ def setupUi(self):
         line.setFrameShape(QFrame.HLine)
         line.setFrameShadow(QFrame.Sunken)
         self.verticalLayout.addWidget(line)
-        self.algorithmItem = QgsGui.instance().processingGuiRegistry().algorithmConfigurationWidget(self._alg)
-        if self.configuration:
-            self.algorithmItem.setConfiguration(self.configuration)
-        self.verticalLayout.addWidget(self.algorithmItem)
 
         widget_context = QgsProcessingParameterWidgetContext()
         if iface is not None:
             widget_context.setMapCanvas(iface.mapCanvas())
         widget_context.setModel(self.model)
         widget_context.setModelChildAlgorithmId(self.childId)
 
+        self.algorithmItem = QgsGui.instance().processingGuiRegistry().algorithmConfigurationWidget(self._alg)
+        if self.algorithmItem:
+            self.algorithmItem.setWidgetContext(widget_context)
+            self.algorithmItem.registerProcessingContextGenerator(self.context_generator)
+        if self.configuration:
+            self.algorithmItem.setConfiguration(self.configuration)
+        self.verticalLayout.addWidget(self.algorithmItem)
+
         for param in self._alg.parameterDefinitions():
             if param.flags() & QgsProcessingParameterDefinition.FlagAdvanced:
                 self.advancedButton = QPushButton()