Merge pull request #38318 from signedav/attachement-expression

Update documuent viewer in the attachment widget on attribute change

python/gui/auto_generated/qgsattributeform.sip.in

@@ -44,6 +44,14 @@ class QgsAttributeForm : QWidget
 
     const QgsFeature &feature();
 
+    QgsFeature currentFormFeature() const;
+%Docstring
+Returns the feature that is currently displayed in the form with all
+the changes received on editing the values in the widgets.
+
+.. versionadded:: 3.16
+%End
+
     void displayWarning( const QString &message );
 %Docstring
 Displays a warning message in the form message bar

src/gui/editorwidgets/qgsexternalresourcewidgetwrapper.cpp

@@ -77,7 +77,7 @@ bool QgsExternalResourceWidgetWrapper::valid() const
   return mLineEdit || mLabel || mQgsWidget;
 }
 
-void QgsExternalResourceWidgetWrapper::setFeature( const QgsFeature &feature )
+void QgsExternalResourceWidgetWrapper::updateProperties( const QgsFeature &feature )
 {
   if ( mQgsWidget && mPropertyCollection.hasActiveProperties() )
   {
@@ -115,12 +115,21 @@ void QgsExternalResourceWidgetWrapper::setFeature( const QgsFeature &feature )
       }
     }
   }
+}
 
+void QgsExternalResourceWidgetWrapper::setFeature( const QgsFeature &feature )
+{
+  updateProperties( feature );
   QgsEditorWidgetWrapper::setFeature( feature );
 }
 
 QWidget *QgsExternalResourceWidgetWrapper::createWidget( QWidget *parent )
 {
+  mForm = qobject_cast<QgsAttributeForm *>( parent );
+
+  if ( mForm )
+    connect( mForm, &QgsAttributeForm::widgetValueChanged, this, &QgsExternalResourceWidgetWrapper::widgetValueChanged );
+
   return new QgsExternalResourceWidget( parent );
 }
 
@@ -252,6 +261,23 @@ void QgsExternalResourceWidgetWrapper::setEnabled( bool enabled )
     mQgsWidget->setReadOnly( !enabled );
 }
 
+void QgsExternalResourceWidgetWrapper::widgetValueChanged( const QString &attribute, const QVariant &newValue, bool attributeChanged )
+{
+  Q_UNUSED( newValue );
+  if ( attributeChanged )
+  {
+    QgsExpression documentViewerContentExp = QgsExpression( mPropertyCollection.property( QgsEditorWidgetWrapper::DocumentViewerContent ).expressionString() );
+    QgsExpression rootPathExp = QgsExpression( mPropertyCollection.property( QgsEditorWidgetWrapper::RootPath ).expressionString() );
+
+    if ( documentViewerContentExp.referencedColumns().contains( attribute ) ||
+         rootPathExp.referencedColumns().contains( attribute ) )
+    {
+      QgsFeature feature = mForm->currentFormFeature();
+      updateProperties( feature );
+    }
+  }
+}
+
 void QgsExternalResourceWidgetWrapper::updateConstraintWidgetStatus()
 {
   if ( mLineEdit )

src/gui/editorwidgets/qgsexternalresourcewidgetwrapper.h

@@ -23,6 +23,7 @@ class QLineEdit;
 
 #include "qgseditorwidgetwrapper.h"
 #include "qgis_gui.h"
+#include "qgsattributeform.h"
 
 SIP_NO_FILE
 
@@ -68,12 +69,26 @@ class GUI_EXPORT QgsExternalResourceWidgetWrapper : public QgsEditorWidgetWrappe
     void setFeature( const QgsFeature &feature ) override;
     void setEnabled( bool enabled ) override;
 
+    /**
+     * Will be called when a value in the current edited form or table row
+     * changes
+     *
+     * \param attribute         The name of the attribute that changed.
+     * \param newValue          The new value of the attribute.
+     * \param attributeChanged  If TRUE, it corresponds to an actual change of the feature attribute
+     * \since QGIS 3.16
+     */
+    void widgetValueChanged( const QString &attribute, const QVariant &newValue, bool attributeChanged );
+
+
   private:
     void updateValues( const QVariant &value, const QVariantList & = QVariantList() ) override;
     void updateConstraintWidgetStatus() override;
+    void updateProperties( const QgsFeature &feature );
 
     QLineEdit *mLineEdit = nullptr;
     QLabel *mLabel = nullptr;
+    QgsAttributeForm *mForm = nullptr;
     QgsExternalResourceWidget *mQgsWidget = nullptr;
 };
 

src/gui/qgsattributeform.cpp

@@ -282,6 +282,7 @@ void QgsAttributeForm::setFeature( const QgsFeature &feature )
 {
   mIsSettingFeature = true;
   mFeature = feature;
+  mCurrentFormFeature = feature;
 
   switch ( mMode )
   {
@@ -872,6 +873,8 @@ void QgsAttributeForm::onAttributeChanged( const QVariant &value, const QVariant
   if ( mValuesInitialized )
     mDirty = true;
 
+  mCurrentFormFeature.setAttribute( eww->field().name(), value );
+
   switch ( mMode )
   {
     case QgsAttributeEditorContext::SingleEditMode:
@@ -957,7 +960,7 @@ void QgsAttributeForm::updateConstraints( QgsEditorWidgetWrapper *eww )
 {
   // get the current feature set in the form
   QgsFeature ft;
-  if ( currentFormFeature( ft ) )
+  if ( currentFormValuesFeature( ft ) )
   {
     // if the layer is NOT being edited then we only check layer based constraints, and not
     // any constraints enforced by the provider. Because:
@@ -1039,7 +1042,7 @@ void QgsAttributeForm::updateLabels()
   if ( ! mLabelDataDefinedProperties.isEmpty() )
   {
     QgsFeature currentFeature;
-    if ( currentFormFeature( currentFeature ) )
+    if ( currentFormValuesFeature( currentFeature ) )
     {
       QgsExpressionContext context = createExpressionContext( currentFeature );
 
@@ -1057,7 +1060,7 @@ void QgsAttributeForm::updateLabels()
   }
 }
 
-bool QgsAttributeForm::currentFormFeature( QgsFeature &feature )
+bool QgsAttributeForm::currentFormValuesFeature( QgsFeature &feature )
 {
   bool rc = true;
   feature = QgsFeature( mFeature );
@@ -2460,7 +2463,7 @@ void QgsAttributeForm::updateJoinedFields( const QgsEditorWidgetWrapper &eww )
   QgsField field = eww.layer()->fields().field( eww.fieldIdx() );
   QList<const QgsVectorLayerJoinInfo *> infos = eww.layer()->joinBuffer()->joinsWhereFieldIsId( field );
 
-  if ( infos.count() == 0 || !currentFormFeature( formFeature ) )
+  if ( infos.count() == 0 || !currentFormValuesFeature( formFeature ) )
     return;
 
   const QString hint = tr( "No feature joined" );

src/gui/qgsattributeform.h

@@ -75,6 +75,14 @@ class GUI_EXPORT QgsAttributeForm : public QWidget
 
     const QgsFeature &feature() { return mFeature; }
 
+    /**
+     * Returns the feature that is currently displayed in the form with all
+     * the changes received on editing the values in the widgets.
+     *
+     * \since QGIS 3.16
+     */
+    QgsFeature currentFormFeature() const { return mCurrentFormFeature; }
+
     /**
      * Displays a warning message in the form message bar
      * \param message message string
@@ -403,7 +411,7 @@ class GUI_EXPORT QgsAttributeForm : public QWidget
     void updateContainersVisibility();
     void updateConstraint( const QgsFeature &ft, QgsEditorWidgetWrapper *eww );
     void updateLabels();
-    bool currentFormFeature( QgsFeature &feature );
+    bool currentFormValuesFeature( QgsFeature &feature );
     bool currentFormValidConstraints( QStringList &invalidFields, QStringList &descriptions );
     QList<QgsEditorWidgetWrapper *> constraintDependencies( QgsEditorWidgetWrapper *w );
 
@@ -411,6 +419,7 @@ class GUI_EXPORT QgsAttributeForm : public QWidget
 
     QgsVectorLayer *mLayer = nullptr;
     QgsFeature mFeature;
+    QgsFeature mCurrentFormFeature;
     QgsMessageBar *mMessageBar = nullptr;
     bool mOwnsMessageBar;
     QgsMessageBarItem *mMultiEditUnsavedMessageBarItem = nullptr;

src/gui/qgsexternalresourcewidget.cpp

@@ -99,7 +99,9 @@ QgsExternalResourceWidget::DocumentViewerContent QgsExternalResourceWidget::docu
 void QgsExternalResourceWidget::setDocumentViewerContent( QgsExternalResourceWidget::DocumentViewerContent content )
 {
   mDocumentViewerContent = content;
-  updateDocumentViewer();
+  if ( mDocumentViewerContent != Image )
+    updateDocumentViewer();
+  loadDocument( mFileWidget->filePath() );
 }
 
 int QgsExternalResourceWidget::documentViewerHeight() const