Forms: expression controlled aliases (labels)

qgis · Apr 13, 2020 · 7334ad0 · 7334ad0
1 parent a84ec12
commit 7334ad0
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Showing 14 changed files with 247 additions and 32 deletions.
diff --git a/python/core/auto_generated/qgsattributeeditorelement.sip.in b/python/core/auto_generated/qgsattributeeditorelement.sip.in
@@ -112,6 +112,20 @@ Controls if this element should be labeled with a title (field, relation or grou
 Controls if this element should be labeled with a title (field, relation or groupname).
 
 .. versionadded:: 2.18
+%End
+
+    QString labelExpression() const;
+%Docstring
+Returns the (possibly empty) label expression
+
+.. versionadded:: 3.14
+%End
+
+    void setLabelExpression( const QString &labelExpression );
+%Docstring
+Sets the label expression to ``labelExpression``
+
+.. versionadded:: 3.14
 %End
 
   protected:

diff --git a/python/core/auto_generated/qgseditformconfig.sip.in b/python/core/auto_generated/qgseditformconfig.sip.in
@@ -191,6 +191,19 @@ on the left hand side.
 Labeling on top leaves more horizontal space for the widget itself.
 %End
 
+    QString labelExpression( int idx ) const;
+%Docstring
+Returns the (possibly empty) expression for the label, to be evaluated in the form context.
+
+.. versionadded:: 3.14
+%End
+
+    void setLabelExpression( int idx, const QString &labelExpression );
+%Docstring
+Set the label expression to ``labelExpression``, to be evaluated in the form context.
+
+.. versionadded:: 3.14
+%End
 
 
     QString initFunction() const;

diff --git a/src/core/qgsattributeeditorelement.cpp b/src/core/qgsattributeeditorelement.cpp
@@ -130,6 +130,16 @@ void QgsAttributeEditorElement::setShowLabel( bool showLabel )
   mShowLabel = showLabel;
 }
 
+QString QgsAttributeEditorElement::labelExpression() const
+{
+  return mLabelExpression;
+}
+
+void QgsAttributeEditorElement::setLabelExpression( const QString &labelExpression )
+{
+  mLabelExpression = labelExpression;
+}
+
 void QgsAttributeEditorRelation::saveConfiguration( QDomElement &elem ) const
 {
   elem.setAttribute( QStringLiteral( "relation" ), mRelation.id() );

diff --git a/src/core/qgsattributeeditorelement.h b/src/core/qgsattributeeditorelement.h
@@ -134,10 +134,23 @@ class CORE_EXPORT QgsAttributeEditorElement SIP_ABSTRACT
      */
     void setShowLabel( bool showLabel );
 
+    /**
+     * Returns the (possibly empty) label expression
+     * \since QGIS 3.14
+     */
+    QString labelExpression() const;
+
+    /**
+     * Sets the label expression to \a labelExpression
+     * \since QGIS 3.14
+     */
+    void setLabelExpression( const QString &labelExpression );
+
   protected:
 #ifndef SIP_RUN
     AttributeEditorType mType;
     QString mName;
+    QString mLabelExpression;
     QgsAttributeEditorElement *mParent = nullptr;
     bool mShowLabel;
 #endif

diff --git a/src/core/qgseditformconfig.cpp b/src/core/qgseditformconfig.cpp
@@ -211,6 +211,23 @@ void QgsEditFormConfig::setLabelOnTop( int idx, bool onTop )
   }
 }
 
+QString QgsEditFormConfig::labelExpression( int idx ) const
+{
+  if ( idx >= 0 && idx < d->mFields.count() )
+    return d->mLabelExpressions.value( d->mFields.at( idx ).name(), QString() );
+  else
+    return QString();
+}
+
+void QgsEditFormConfig::setLabelExpression( int idx, const QString &labelExpression )
+{
+  if ( idx >= 0 && idx < d->mFields.count() )
+  {
+    d.detach();
+    d->mLabelExpressions[ d->mFields.at( idx ).name() ] = labelExpression;
+  }
+}
+
 QString QgsEditFormConfig::initFunction() const
 {
   return d->mInitFunction;
@@ -382,6 +399,14 @@ void QgsEditFormConfig::readXml( const QDomNode &node, QgsReadWriteContext &cont
     d->mLabelOnTop.insert( labelOnTopElement.attribute( QStringLiteral( "name" ) ), static_cast< bool >( labelOnTopElement.attribute( QStringLiteral( "labelOnTop" ) ).toInt() ) );
   }
 
+  d->mLabelExpressions.clear();
+  QDomNodeList labelExpressionsNodeList = node.namedItem( QStringLiteral( "labelExpression" ) ).toElement().childNodes();
+  for ( int i = 0; i < labelExpressionsNodeList.size(); ++i )
+  {
+    QDomElement labelExpressionElement = labelExpressionsNodeList.at( i ).toElement();
+    d->mLabelExpressions.insert( labelExpressionElement.attribute( QStringLiteral( "name" ) ), labelExpressionElement.attribute( QStringLiteral( "labelExpression" ) ) );
+  }
+
   QDomNodeList widgetsNodeList = node.namedItem( QStringLiteral( "widgets" ) ).toElement().childNodes();
 
   for ( int i = 0; i < widgetsNodeList.size(); ++i )
@@ -505,6 +530,16 @@ void QgsEditFormConfig::writeXml( QDomNode &node, const QgsReadWriteContext &con
   }
   node.appendChild( labelOnTopElem );
 
+  QDomElement labelExpressionElem = doc.createElement( QStringLiteral( "labelExpression" ) );
+  for ( auto labelExpressionsIt = d->mLabelExpressions.constBegin(); labelExpressionsIt != d->mLabelExpressions.constEnd(); ++labelExpressionsIt )
+  {
+    QDomElement fieldElem = doc.createElement( QStringLiteral( "field" ) );
+    fieldElem.setAttribute( QStringLiteral( "name" ), labelExpressionsIt.key() );
+    fieldElem.setAttribute( QStringLiteral( "labelExpression" ), labelExpressionsIt.value() );
+    labelExpressionElem.appendChild( fieldElem );
+  }
+  node.appendChild( labelExpressionElem );
+
   QDomElement widgetsElem = doc.createElement( QStringLiteral( "widgets" ) );
 
   QMap<QString, QVariantMap >::ConstIterator configIt( d->mWidgetConfigs.constBegin() );
@@ -604,6 +639,8 @@ QgsAttributeEditorElement *QgsEditFormConfig::attributeEditorElementFromDomEleme
       newElement->setShowLabel( elem.attribute( QStringLiteral( "showLabel" ) ).toInt() );
     else
       newElement->setShowLabel( true );
+    if ( elem.hasAttribute( QStringLiteral( "labelExpression" ) ) )
+      newElement->setLabelExpression( elem.attribute( QStringLiteral( "labelExpression" ) ) );
   }
 
   return newElement;

diff --git a/src/core/qgseditformconfig.h b/src/core/qgseditformconfig.h
@@ -219,6 +219,17 @@ class CORE_EXPORT QgsEditFormConfig
      **/
     void setLabelOnTop( int idx, bool onTop );
 
+    /**
+     * Returns the (possibly empty) expression for the label, to be evaluated in the form context.
+     * \since QGIS 3.14
+     **/
+    QString labelExpression( int idx ) const;
+
+    /**
+     * Set the label expression to \a labelExpression, to be evaluated in the form context.
+     * \since QGIS 3.14
+     **/
+    void setLabelExpression( int idx, const QString &labelExpression );
 
     // Python form init function stuff
 

diff --git a/src/core/qgseditformconfig_p.h b/src/core/qgseditformconfig_p.h
@@ -36,6 +36,7 @@ class QgsEditFormConfigPrivate : public QSharedData
       , mConfiguredRootContainer( o.mConfiguredRootContainer )
       , mFieldEditables( o.mFieldEditables )
       , mLabelOnTop( o.mLabelOnTop )
+      , mLabelExpressions( o.mLabelExpressions )
       , mWidgetConfigs( o.mWidgetConfigs )
       , mEditorLayout( o.mEditorLayout )
       , mUiFormPath( o.mUiFormPath )
@@ -59,6 +60,7 @@ class QgsEditFormConfigPrivate : public QSharedData
 
     QMap< QString, bool> mFieldEditables;
     QMap< QString, bool> mLabelOnTop;
+    QMap< QString, QString> mLabelExpressions;
 
     QMap<QString, QVariantMap > mWidgetConfigs;
 

diff --git a/src/gui/attributeformconfig/qgsattributetypedialog.cpp b/src/gui/attributeformconfig/qgsattributetypedialog.cpp
@@ -73,6 +73,9 @@ QgsAttributeTypeDialog::QgsAttributeTypeDialog( QgsVectorLayer *vl, int fieldIdx
   mExpressionWidget->registerExpressionContextGenerator( this );
   mExpressionWidget->setLayer( mLayer );
 
+  mAliasExpression->registerExpressionContextGenerator( this );
+  mAliasExpression->setLayer( mLayer );
+
   connect( mExpressionWidget, &QgsExpressionLineEdit::expressionChanged, this, &QgsAttributeTypeDialog::defaultExpressionChanged );
   connect( mUniqueCheckBox, &QCheckBox::toggled, this, [ = ]( bool checked )
   {
@@ -92,6 +95,8 @@ QgsAttributeTypeDialog::QgsAttributeTypeDialog( QgsVectorLayer *vl, int fieldIdx
 
   constraintExpressionWidget->setAllowEmptyFieldName( true );
   constraintExpressionWidget->setLayer( vl );
+
+  // TODO: mAliasExpression->registerExpressionContextGenerator( ... );
 }
 
 QgsAttributeTypeDialog::~QgsAttributeTypeDialog()
@@ -303,8 +308,14 @@ QgsExpressionContext QgsAttributeTypeDialog::createExpressionContext() const
       << QgsExpressionContextUtils::globalScope()
       << QgsExpressionContextUtils::projectScope( QgsProject::instance() )
       << QgsExpressionContextUtils::layerScope( mLayer )
+      << QgsExpressionContextUtils::formScope( QgsFeature( mLayer->fields() ) )
       << QgsExpressionContextUtils::mapToolCaptureScope( QList<QgsPointLocator::Match>() );
 
+  context.setHighlightedFunctions( QStringList() << QStringLiteral( "current_value" ) );
+  context.setHighlightedVariables( QStringList() << QStringLiteral( "current_geometry" )
+                                   << QStringLiteral( "current_feature" )
+                                   << QStringLiteral( "form_mode" ) );
+
   return context;
 }
 
@@ -339,12 +350,22 @@ void QgsAttributeTypeDialog::setFieldEditable( bool editable )
 
 void QgsAttributeTypeDialog::setAlias( const QString &alias )
 {
-  leAlias->setText( alias );
+  mAlias->setText( alias );
 }
 
 QString QgsAttributeTypeDialog::alias() const
 {
-  return leAlias->text();
+  return mAlias->text();
+}
+
+void QgsAttributeTypeDialog::setAliasExpression( const QString &aliasExpression )
+{
+  mAliasExpression->setExpression( aliasExpression );
+}
+
+QString QgsAttributeTypeDialog::aliasExpression() const
+{
+  return mAliasExpression->expression();
 }
 
 void QgsAttributeTypeDialog::setComment( const QString &comment )

diff --git a/src/gui/attributeformconfig/qgsattributetypedialog.h b/src/gui/attributeformconfig/qgsattributetypedialog.h
@@ -76,6 +76,18 @@ class GUI_EXPORT QgsAttributeTypeDialog: public QWidget, private Ui::QgsAttribut
      */
     QString alias() const;
 
+    /**
+     * Sets expression for for label alias
+     * \since QGIS 3.14
+     */
+    void setAliasExpression( const QString &aliasExpression );
+
+    /**
+     * Returns the expression for the label alias
+     * \since QGIS 3.14
+     */
+    QString aliasExpression() const;
+
     /**
      * Setter for label comment
      */

diff --git a/src/gui/qgsattributeform.cpp b/src/gui/qgsattributeform.cpp
@@ -86,6 +86,7 @@ QgsAttributeForm::QgsAttributeForm( QgsVectorLayer *vl, const QgsFeature &featur
   connect( this, &QgsAttributeForm::modeChanged, this, &QgsAttributeForm::updateContainersVisibility );
 
   updateContainersVisibility();
+
 }
 
 QgsAttributeForm::~QgsAttributeForm()
@@ -305,6 +306,7 @@ void QgsAttributeForm::setFeature( const QgsFeature &feature )
     }
   }
   mIsSettingFeature = false;
+  mExpressionContext.setFeature( feature );
 }
 
 bool QgsAttributeForm::saveEdits()
@@ -899,6 +901,9 @@ void QgsAttributeForm::onAttributeChanged( const QVariant &value, const QVariant
   updateDefaultValues( eww->fieldIdx() );
   mAlreadyUpdatedFields.removeAll( eww->fieldIdx() );
 
+  // Updates expression controlled labels
+  updateLabels();
+
   if ( !signalEmitted )
   {
     Q_NOWARN_DEPRECATED_PUSH
@@ -1002,6 +1007,28 @@ void QgsAttributeForm::updateConstraint( const QgsFeature &ft, QgsEditorWidgetWr
   eww->updateConstraint( ft, constraintOrigin );
 }
 
+void QgsAttributeForm::updateLabels()
+{
+  if ( ! mExpressionLabels.isEmpty() )
+  {
+    QgsFeature currentFeature;
+    if ( currentFormFeature( currentFeature ) )
+    {
+      mExpressionContext << QgsExpressionContextUtils::formScope( currentFeature, mContext.attributeFormModeString() );
+      mExpressionContext.setFields( mLayer->fields() );
+      for ( auto it = mExpressionLabels.constBegin() ; it != mExpressionLabels.constEnd(); ++it )
+      {
+        QLabel *label { it.key() };
+        QgsExpression exp { it.value() };
+        if ( exp.prepare( &mExpressionContext ) && ! exp.hasParserError() )
+        {
+          label->setText( exp.evaluate( &mExpressionContext ).toString() );
+        }
+      }
+    }
+  }
+}
+
 bool QgsAttributeForm::currentFormFeature( QgsFeature &feature )
 {
   bool rc = true;
@@ -1443,6 +1470,10 @@ void QgsAttributeForm::init()
         }
         else
         {
+          if ( ! widgetInfo.labelExpression.isEmpty() )
+          {
+            mExpressionLabels[ label ] = QgsExpression( widgetInfo.labelExpression );
+          }
           layout->addWidget( label, row, column++ );
           layout->addWidget( widgetInfo.widget, row, column++ );
         }
@@ -1498,6 +1529,7 @@ void QgsAttributeForm::init()
       QString labelText = fieldName;
       labelText.replace( '&', QStringLiteral( "&&" ) ); // need to escape '&' or they'll be replace by _ in the label text
 
+      const QString labelExpression { mLayer->editFormConfig().labelExpression( idx ) };
       const QgsEditorWidgetSetup widgetSetup = QgsGui::editorWidgetRegistry()->findBest( mLayer, field.name() );
 
       if ( widgetSetup.type() == QLatin1String( "Hidden" ) )
@@ -1506,11 +1538,16 @@ void QgsAttributeForm::init()
       bool labelOnTop = mLayer->editFormConfig().labelOnTop( idx );
 
       // This will also create the widget
-      QLabel *l = new QLabel( labelText );
-      l->setToolTip( QgsFieldModel::fieldToolTipExtended( field, mLayer ) );
+      QLabel *label = new QLabel( labelText );
+      label->setToolTip( QgsFieldModel::fieldToolTipExtended( field, mLayer ) );
       QSvgWidget *i = new QSvgWidget();
       i->setFixedSize( 18, 18 );
 
+      if ( ! labelExpression.isEmpty() )
+      {
+        mExpressionLabels[ label ] = QgsExpression( labelExpression );
+      }
+
       QgsEditorWidgetWrapper *eww = QgsGui::editorWidgetRegistry()->create( widgetSetup.type(), mLayer, idx, widgetSetup.config(), nullptr, this, mContext );
 
       QWidget *w = nullptr;
@@ -1522,7 +1559,7 @@ void QgsAttributeForm::init()
         mFormWidgets.append( formWidget );
         formWidget->createSearchWidgetWrappers( mContext );
 
-        l->setBuddy( eww->widget() );
+        label->setBuddy( eww->widget() );
       }
       else
       {
@@ -1541,16 +1578,17 @@ void QgsAttributeForm::init()
 
       if ( labelOnTop )
       {
-        gridLayout->addWidget( l, row++, 0, 1, 2 );
+        gridLayout->addWidget( label, row++, 0, 1, 2 );
         gridLayout->addWidget( w, row++, 0, 1, 2 );
         gridLayout->addWidget( i, row++, 0, 1, 2 );
       }
       else
       {
-        gridLayout->addWidget( l, row, 0 );
+        gridLayout->addWidget( label, row, 0 );
         gridLayout->addWidget( w, row, 1 );
         gridLayout->addWidget( i, row++, 2 );
       }
+
     }
 
     const QList<QgsRelation> relations = QgsProject::instance()->relationManager()->referencedRelations( mLayer );
@@ -2048,6 +2086,7 @@ QgsAttributeForm::WidgetInfo QgsAttributeForm::createWidgetFromDef( const QgsAtt
   }
 
   newWidgetInfo.showLabel = widgetDef->showLabel();
+  newWidgetInfo.labelExpression = widgetDef->labelExpression();
 
   return newWidgetInfo;
 }