Add UI for setting default field value expressions in the

field property dialog

Sponsored by DB Fahrwegdienste GmbH

src/app/qgsattributetypedialog.cpp

@@ -72,7 +72,7 @@ QgsAttributeTypeDialog::QgsAttributeTypeDialog( QgsVectorLayer *vl, int fieldIdx
   QSettings settings;
   restoreGeometry( settings.value( "/Windows/QgsAttributeTypeDialog/geometry" ).toByteArray() );
 
-  constraintExpression->setLayer( vl );
+  constraintExpressionWidget->setLayer( vl );
 }
 
 QgsAttributeTypeDialog::~QgsAttributeTypeDialog()
@@ -180,29 +180,39 @@ bool QgsAttributeTypeDialog::labelOnTop() const
   return labelOnTopCheckBox->isChecked();
 }
 
-void QgsAttributeTypeDialog::setExpressionDescription( const QString &desc )
+void QgsAttributeTypeDialog::setConstraintExpressionDescription( const QString &desc )
 {
-  constraintExpressionDescription->setText( desc );
+  leConstraintExpressionDescription->setText( desc );
 }
 
-QString QgsAttributeTypeDialog::expressionDescription()
+QString QgsAttributeTypeDialog::constraintExpressionDescription()
 {
-  return constraintExpressionDescription->text();
+  return leConstraintExpressionDescription->text();
 }
 
 bool QgsAttributeTypeDialog::notNull() const
 {
   return notNullCheckBox->isChecked();
 }
 
-void QgsAttributeTypeDialog::setExpression( const QString &str )
+void QgsAttributeTypeDialog::setConstraintExpression( const QString &str )
 {
-  constraintExpression->setField( str );
+  constraintExpressionWidget->setField( str );
 }
 
-QString QgsAttributeTypeDialog::expression() const
+QString QgsAttributeTypeDialog::defaultValueExpression() const
 {
-  return constraintExpression->asExpression();
+  return mExpressionWidget->expression();
+}
+
+void QgsAttributeTypeDialog::setDefaultValueExpression( const QString& expression )
+{
+  mExpressionWidget->setExpression( expression );
+}
+
+QString QgsAttributeTypeDialog::constraintExpression() const
+{
+  return constraintExpressionWidget->asExpression();
 }
 
 void QgsAttributeTypeDialog::setFieldEditable( bool editable )

src/app/qgsattributetypedialog.h

@@ -99,26 +99,37 @@ class APP_EXPORT QgsAttributeTypeDialog: public QDialog, private Ui::QgsAttribut
      * @param desc the expression description
      * @note added in QGIS 2.16
      **/
-    void setExpressionDescription( const QString &desc );
+    void setConstraintExpressionDescription( const QString &desc );
 
     /**
      * Getter for constraint expression description
      * @return the expression description
      * @note added in QGIS 2.16
      **/
-    QString expressionDescription();
+    QString constraintExpressionDescription();
 
     /**
      * Getter for the constraint expression
      * @note added in QGIS 2.16
      */
-    QString expression() const;
+    QString constraintExpression() const;
 
     /**
      * Setter for the constraint expression
      * @note added in QGIS 2.16
      */
-    void setExpression( const QString &str );
+    void setConstraintExpression( const QString &str );
+
+    /**
+     * Returns the expression used for the field's default value, or
+     * an empty string if no default value expression is set.
+     */
+    QString defaultValueExpression() const;
+
+    /**
+     * Sets the expression used for the field's default value
+     */
+    void setDefaultValueExpression( const QString& expression );
 
   private slots:
     /**

src/app/qgsfeatureaction.cpp

@@ -143,6 +143,11 @@ bool QgsFeatureAction::addFeature( const QgsAttributeMap& defaultAttributes, boo
   bool reuseLastValues = settings.value( "/qgis/digitizing/reuseLastValues", false ).toBool();
   QgsDebugMsg( QString( "reuseLastValues: %1" ).arg( reuseLastValues ) );
 
+  QgsExpressionContext context;
+  context << QgsExpressionContextUtils::globalScope()
+  << QgsExpressionContextUtils::projectScope()
+  << QgsExpressionContextUtils::layerScope( mLayer );
+
   // add the fields to the QgsFeature
   const QgsFields& fields = mLayer->fields();
   mFeature->initAttributes( fields.count() );
@@ -154,6 +159,11 @@ bool QgsFeatureAction::addFeature( const QgsAttributeMap& defaultAttributes, boo
     {
       v = defaultAttributes.value( idx );
     }
+    else if ( !mLayer->defaultValueExpression( idx ).isEmpty() )
+    {
+      // client side default expression set - use this in preference to reusing last value
+      v = mLayer->defaultValue( idx, *mFeature, &context );
+    }
     else if ( reuseLastValues && sLastUsedValues.contains( mLayer ) && sLastUsedValues[ mLayer ].contains( idx ) && !pkAttrList.contains( idx ) )
     {
       v = sLastUsedValues[ mLayer ][idx];

src/app/qgsfieldsproperties.cpp

@@ -553,8 +553,9 @@ void QgsFieldsProperties::attributeTypeDialog()
   attributeTypeDialog.setFieldEditable( cfg.mEditable );
   attributeTypeDialog.setLabelOnTop( cfg.mLabelOnTop );
   attributeTypeDialog.setNotNull( cfg.mNotNull );
-  attributeTypeDialog.setExpression( cfg.mConstraint );
-  attributeTypeDialog.setExpressionDescription( cfg.mConstraintDescription );
+  attributeTypeDialog.setConstraintExpression( cfg.mConstraint );
+  attributeTypeDialog.setConstraintExpressionDescription( cfg.mConstraintDescription );
+  attributeTypeDialog.setDefaultValueExpression( mLayer->defaultValueExpression( index ) );
 
   attributeTypeDialog.setWidgetV2Config( cfg.mEditorWidgetV2Config );
   attributeTypeDialog.setWidgetV2Type( cfg.mEditorWidgetV2Type );
@@ -565,8 +566,9 @@ void QgsFieldsProperties::attributeTypeDialog()
   cfg.mEditable = attributeTypeDialog.fieldEditable();
   cfg.mLabelOnTop = attributeTypeDialog.labelOnTop();
   cfg.mNotNull = attributeTypeDialog.notNull();
-  cfg.mConstraintDescription = attributeTypeDialog.expressionDescription();
-  cfg.mConstraint = attributeTypeDialog.expression();
+  cfg.mConstraintDescription = attributeTypeDialog.constraintExpressionDescription();
+  cfg.mConstraint = attributeTypeDialog.constraintExpression();
+  mLayer->setDefaultValueExpression( index, attributeTypeDialog.defaultValueExpression() );
 
   cfg.mEditorWidgetV2Type = attributeTypeDialog.editorWidgetV2Type();
   cfg.mEditorWidgetV2Config = attributeTypeDialog.editorWidgetV2Config();

src/ui/qgsattributetypeedit.ui

@@ -51,6 +51,30 @@
     <widget class="QStackedWidget" name="stackedWidget"/>
    </item>
    <item row="2" column="1">
+    <layout class="QHBoxLayout" name="horizontalLayout_3">
+     <item>
+      <widget class="QLabel" name="label_3">
+       <property name="text">
+        <string>Default value</string>
+       </property>
+      </widget>
+     </item>
+     <item>
+      <widget class="QgsExpressionLineEdit" name="mExpressionWidget" native="true">
+       <property name="maximumSize">
+        <size>
+         <width>500</width>
+         <height>16777215</height>
+        </size>
+       </property>
+       <property name="focusPolicy">
+        <enum>Qt::StrongFocus</enum>
+       </property>
+      </widget>
+     </item>
+    </layout>
+   </item>
+   <item row="3" column="1">
     <widget class="QCheckBox" name="notNullCheckBox">
      <property name="text">
       <string>Not null</string>
@@ -70,7 +94,7 @@
       </widget>
      </item>
      <item>
-      <widget class="QgsFieldExpressionWidget" name="constraintExpression" native="true"/>
+      <widget class="QgsFieldExpressionWidget" name="constraintExpressionWidget" native="true"/>
      </item>
     </layout>
    </item>
@@ -87,13 +111,19 @@
       </widget>
      </item>
      <item>
-      <widget class="QLineEdit" name="constraintExpressionDescription"/>
+      <widget class="QLineEdit" name="leConstraintExpressionDescription"/>
      </item>
     </layout>
    </item>
   </layout>
  </widget>
  <customwidgets>
+  <customwidget>
+   <class>QgsExpressionLineEdit</class>
+   <extends>QWidget</extends>
+   <header>qgsexpressionlineedit.h</header>
+   <container>1</container>
+  </customwidget>
   <customwidget>
    <class>QgsFieldExpressionWidget</class>
    <extends>QWidget</extends>