Ensure correct expression context is shown in expression builder

for form container visibility (cherry picked from commit f56327a)
qgis · Apr 30, 2020 · baee39f · baee39f
1 parent 79b82c3
commit baee39f
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Showing 4 changed files with 24 additions and 4 deletions.
diff --git a/src/app/attributeformconfig/qgsattributeformcontaineredit.cpp b/src/app/attributeformconfig/qgsattributeformcontaineredit.cpp
@@ -48,6 +48,11 @@ QgsAttributeFormContainerEdit::QgsAttributeFormContainerEdit( QTreeWidgetItem *i
   connect( mShowAsGroupBoxCheckBox, &QCheckBox::stateChanged, mShowLabelCheckBox, &QCheckBox::setEnabled );
 }
 
+void QgsAttributeFormContainerEdit::registerExpressionContextGenerator( QgsExpressionContextGenerator *generator )
+{
+  mVisibilityExpressionWidget->registerExpressionContextGenerator( generator );
+}
+
 void QgsAttributeFormContainerEdit::updateItemData()
 {
   QgsAttributesFormProperties::DnDTreeItemData itemData = mTreeItem->data( 0, QgsAttributesFormProperties::DnDTreeRole ).value<QgsAttributesFormProperties::DnDTreeItemData>();

diff --git a/src/app/attributeformconfig/qgsattributeformcontaineredit.h b/src/app/attributeformconfig/qgsattributeformcontaineredit.h
@@ -34,12 +34,17 @@ class APP_EXPORT QgsAttributeFormContainerEdit: public QWidget, private Ui_QgsAt
   public:
     explicit QgsAttributeFormContainerEdit( QTreeWidgetItem *item, QWidget *parent = nullptr );
 
+    /**
+     * Register an expression context generator class that will be used to retrieve
+     * an expression context for the widget when required.
+     * \since QGIS 3.14
+     */
+    void registerExpressionContextGenerator( QgsExpressionContextGenerator *generator );
 
     void updateItemData();
 
-
   private:
-    QTreeWidgetItem *mTreeItem;
+    QTreeWidgetItem *mTreeItem = nullptr;
 };
 
 #endif // QGSATTRIBUTEFORMCONTAINEREDIT_H
diff --git a/src/app/qgsattributesformproperties.cpp b/src/app/qgsattributesformproperties.cpp
@@ -26,6 +26,7 @@
 #include "qgsapplication.h"
 #include "qgscolorbutton.h"
 #include "qgscodeeditorhtml.h"
+#include "qgsexpressioncontextutils.h"
 
 
 QgsAttributesFormProperties::QgsAttributesFormProperties( QgsVectorLayer *layer, QWidget *parent )
@@ -183,9 +184,15 @@ void QgsAttributesFormProperties::initSuppressCombo()
   mFormSuppressCmbBx->addItem( tr( "Show form on add feature" ) );
 
   mFormSuppressCmbBx->setCurrentIndex( mLayer->editFormConfig().suppress() );
+}
 
-
+QgsExpressionContext QgsAttributesFormProperties::createExpressionContext() const
+{
+  QgsExpressionContext context;
+  context.appendScopes( QgsExpressionContextUtils::globalProjectLayerScopes( mLayer ) );
+  return context;
 }
+
 void QgsAttributesFormProperties::initLayoutConfig()
 {
   mEditorLayoutComboBox->setCurrentIndex( mEditorLayoutComboBox->findData( mLayer->editFormConfig().layout() ) );
@@ -428,6 +435,7 @@ void QgsAttributesFormProperties::loadAttributeContainerEdit()
 
   QTreeWidgetItem *currentItem = mFormLayoutTree->selectedItems().at( 0 );
   mAttributeContainerEdit = new QgsAttributeFormContainerEdit( currentItem, this );
+  mAttributeContainerEdit->registerExpressionContextGenerator( this );
   mAttributeContainerEdit->layout()->setContentsMargins( 0, 0, 0, 0 );
   mAttributeTypeFrame->layout()->setContentsMargins( 0, 0, 0, 0 );
   mAttributeTypeFrame->layout()->addWidget( mAttributeContainerEdit );

diff --git a/src/app/qgsattributesformproperties.h b/src/app/qgsattributesformproperties.h
@@ -52,7 +52,7 @@ class QgsAttributeRelationEdit;
 class QgsAttributeWidgetEdit;
 class DnDTree;
 
-class APP_EXPORT QgsAttributesFormProperties : public QWidget, private Ui_QgsAttributesFormProperties
+class APP_EXPORT QgsAttributesFormProperties : public QWidget, public QgsExpressionContextGenerator, private Ui_QgsAttributesFormProperties
 {
     Q_OBJECT
 
@@ -208,6 +208,8 @@ class APP_EXPORT QgsAttributesFormProperties : public QWidget, private Ui_QgsAtt
     void initInitPython();
     void initSuppressCombo();
 
+    QgsExpressionContext createExpressionContext() const override;
+
   protected:
     void updateButtons();