[processing][model] Fix handling of mandatory checkbox in output definitions

Author: nyalldawson

python/core/processing/models/qgsprocessingmodeloutput.sip.in

@@ -58,6 +58,28 @@ Sets the default value for the model output.
 
 .. seealso:: :py:func:`defaultValue`
 
+.. versionadded:: 3.2
+%End
+
+    bool isMandatory() const;
+%Docstring
+Returns true if the output is mandatory. This may override the associated
+child algorithm's parameter optional status - e.g. allowing
+an optional output from an algorithm to be mandatory within a model.
+
+.. seealso:: :py:func:`setMandatory`
+
+.. versionadded:: 3.2
+%End
+
+    void setMandatory( bool mandatory );
+%Docstring
+Sets whether the output is ``mandatory``. This may override the associated
+child algorithm's parameter optional status - e.g. allowing
+an optional output from an algorithm to be mandatory within a model.
+
+.. seealso:: :py:func:`isMandatory`
+
 .. versionadded:: 3.2
 %End
 

python/plugins/processing/modeler/ModelerGraphicItem.py

@@ -233,6 +233,7 @@ def editElement(self):
                 model_output = child_alg.modelOutput(self.element.name())
                 model_output.setDescription(dlg.param.description())
                 model_output.setDefaultValue(dlg.param.defaultValue())
+                model_output.setMandatory(not (dlg.param.flags() & QgsProcessingParameterDefinition.FlagOptional))
                 self.model.updateDestinationParameters()
 
     def updateAlgorithm(self, alg):

python/plugins/processing/modeler/ModelerParameterDefinitionDialog.py

@@ -443,34 +443,29 @@ def accept(self):
                 name=name,
                 description=self.param.description(),
                 type=self.param.dataType(),
-                defaultValue=self.defaultWidget.getValue(),
-                optional=self.param.flags() & QgsProcessingParameterDefinition.FlagOptional)
+                defaultValue=self.defaultWidget.getValue())
         elif (isinstance(self.param, QgsProcessingParameterFileDestination)):
             self.param = QgsProcessingParameterFileDestination(
                 name=name,
                 description=self.param.description(),
                 fileFilter=self.param.fileFilter(),
-                defaultValue=str(self.defaultWidget.getValue()),
-                optional=self.param.flags() & QgsProcessingParameterDefinition.FlagOptional)
+                defaultValue=str(self.defaultWidget.getValue()))
         elif (isinstance(self.param, QgsProcessingParameterFolderDestination)):
             self.param = QgsProcessingParameterFolderDestination(
                 name=name,
                 description=self.param.description(),
-                defaultValue=str(self.defaultWidget.getValue()),
-                optional=self.param.flags() & QgsProcessingParameterDefinition.FlagOptional)
+                defaultValue=str(self.defaultWidget.getValue()))
         elif (isinstance(self.param, QgsProcessingParameterRasterDestination)):
             self.param = QgsProcessingParameterRasterDestination(
                 name=name,
                 description=self.param.description(),
-                defaultValue=str(self.defaultWidget.getValue()),
-                optional=self.param.flags() & QgsProcessingParameterDefinition.FlagOptional)
+                defaultValue=str(self.defaultWidget.getValue()))
         elif (isinstance(self.param, QgsProcessingParameterVectorDestination)):
             self.param = QgsProcessingParameterVectorDestination(
                 name=name,
                 description=self.param.description(),
                 type=self.param.dataType(),
-                defaultValue=str(self.defaultWidget.getValue()),
-                optional=self.param.flags() & QgsProcessingParameterDefinition.FlagOptional)
+                defaultValue=str(self.defaultWidget.getValue()))
 
         else:
             if self.paramType:
@@ -488,6 +483,8 @@ def accept(self):
 
         if not self.requiredCheck.isChecked():
             self.param.setFlags(self.param.flags() | QgsProcessingParameterDefinition.FlagOptional)
+        else:
+            self.param.setFlags(self.param.flags() & ~QgsProcessingParameterDefinition.FlagOptional)
 
         settings = QgsSettings()
         settings.setValue("/Processing/modelParametersDefinitionDialogGeometry", self.saveGeometry())

src/core/processing/models/qgsprocessingmodelalgorithm.cpp

@@ -786,6 +786,8 @@ void QgsProcessingModelAlgorithm::updateDestinationParameters()
       // Even if an output was hidden in a child algorithm, we want to show it here for the final
       // outputs.
       param->setFlags( param->flags() & ~QgsProcessingParameterDefinition::FlagHidden );
+      if ( outputIt->isMandatory() )
+        param->setFlags( param->flags() & ~QgsProcessingParameterDefinition::FlagOptional );
       param->setName( outputIt->childId() + ':' + outputIt->name() );
       param->setDescription( outputIt->description() );
       param->setDefaultValue( outputIt->defaultValue() );

src/core/processing/models/qgsprocessingmodeloutput.cpp

@@ -42,6 +42,7 @@ QVariant QgsProcessingModelOutput::toVariant() const
 
   map.insert( QStringLiteral( "child_id" ), mChildId );
   map.insert( QStringLiteral( "output_name" ), mOutputName );
+  map.insert( QStringLiteral( "mandatory" ), mMandatory );
   saveCommonProperties( map );
   return map;
 }
@@ -72,6 +73,7 @@ bool QgsProcessingModelOutput::loadVariant( const QVariantMap &map )
 
   mChildId = map.value( QStringLiteral( "child_id" ) ).toString();
   mOutputName = map.value( QStringLiteral( "output_name" ) ).toString();
+  mMandatory = map.value( QStringLiteral( "mandatory" ), false ).toBool();
   restoreCommonProperties( map );
   return true;
 }

src/core/processing/models/qgsprocessingmodeloutput.h

@@ -70,6 +70,24 @@ class CORE_EXPORT QgsProcessingModelOutput : public QgsProcessingModelComponent
      */
     void setDefaultValue( const QVariant &value ) { mDefaultValue = value; }
 
+    /**
+     * Returns true if the output is mandatory. This may override the associated
+     * child algorithm's parameter optional status - e.g. allowing
+     * an optional output from an algorithm to be mandatory within a model.
+     * \see setMandatory()
+     * \since QGIS 3.2
+     */
+    bool isMandatory() const { return mMandatory; }
+
+    /**
+     * Sets whether the output is \a mandatory. This may override the associated
+     * child algorithm's parameter optional status - e.g. allowing
+     * an optional output from an algorithm to be mandatory within a model.
+     * \see isMandatory()
+     * \since QGIS 3.2
+     */
+    void setMandatory( bool mandatory ) { mMandatory = mandatory; }
+
     /**
      * Returns the child algorithm ID from which this output is generated.
      * \see setChildId()
@@ -112,6 +130,7 @@ class CORE_EXPORT QgsProcessingModelOutput : public QgsProcessingModelComponent
     QVariant mDefaultValue;
     QString mChildId;
     QString mOutputName;
+    bool mMandatory = false;
 };
 
 ///@endcond