src/core/symbology-ng/qgscategorizedsymbolrendererv2.cpp

@@ -197,14 +197,18 @@ QgsSymbolV2* QgsCategorizedSymbolRendererV2::symbolForValue( QVariant value )
 QgsSymbolV2* QgsCategorizedSymbolRendererV2::symbolForFeature( QgsFeature& feature )
 {
   const QgsAttributes& attrs = feature.attributes();
+  QVariant value;
   if ( mAttrNum < 0 || mAttrNum >= attrs.count() )
   {
-    QgsDebugMsg( "attribute '" + mAttrName + "' (index " + QString::number( mAttrNum ) + ") required by renderer not found" );
-    return NULL;
+      value = mExpression->evaluate( &feature );
+  }
+  else
+  {
+      value = attrs[mAttrNum];
   }
 
   // find the right symbol for the category
-  QgsSymbolV2* symbol = symbolForValue( attrs[mAttrNum] );
+  QgsSymbolV2* symbol = symbolForValue( value );
   if ( symbol == NULL )
   {
     // if no symbol found use default one
@@ -361,6 +365,11 @@ void QgsCategorizedSymbolRendererV2::startRender( QgsRenderContext& context, con
 
   // find out classification attribute index from name
   mAttrNum = vlayer ? vlayer->fieldNameIndex( mAttrName ) : -1;
+  if ( mAttrNum == -1 )
+  {
+      mExpression = new QgsExpression( mAttrName );
+      mExpression->prepare( vlayer->pendingFields() );
+  }
 
   mRotationFieldIdx  = ( mRotationField.isEmpty()  ? -1 : vlayer->fieldNameIndex( mRotationField ) );
   mSizeScaleFieldIdx = ( mSizeScaleField.isEmpty() ? -1 : vlayer->fieldNameIndex( mSizeScaleField ) );
@@ -401,7 +410,11 @@ void QgsCategorizedSymbolRendererV2::stopRender( QgsRenderContext& context )
 QList<QString> QgsCategorizedSymbolRendererV2::usedAttributes()
 {
   QSet<QString> attributes;
-  attributes.insert( mAttrName );
+  QgsExpression exp( mAttrName );
+  foreach (QString attr, exp.referencedColumns() )
+  {
+      attributes << attr;
+  }
   if ( !mRotationField.isEmpty() )
   {
     attributes.insert( mRotationField );

src/core/symbology-ng/qgscategorizedsymbolrendererv2.h

@@ -17,6 +17,7 @@
 
 #include "qgssymbolv2.h"
 #include "qgsrendererv2.h"
+#include "qgsexpression.h"
 
 #include <QHash>
 
@@ -155,6 +156,7 @@ class CORE_EXPORT QgsCategorizedSymbolRendererV2 : public QgsFeatureRendererV2
     QString mRotationField;
     QString mSizeScaleField;
     QgsSymbolV2::ScaleMethod mScaleMethod;
+    QgsExpression* mExpression;
 
     //! attribute index (derived from attribute name in startRender)
     int mAttrNum;

src/core/symbology-ng/qgsgraduatedsymbolrendererv2.cpp

@@ -22,7 +22,7 @@
 #include "qgsvectorlayer.h"
 #include "qgslogger.h"
 #include "qgsvectordataprovider.h"
-
+#include "qgsexpression.h"
 #include <QDomDocument>
 #include <QDomElement>
 #include <QSettings> // for legend
@@ -184,18 +184,22 @@ QgsSymbolV2* QgsGraduatedSymbolRendererV2::symbolForValue( double value )
 QgsSymbolV2* QgsGraduatedSymbolRendererV2::symbolForFeature( QgsFeature& feature )
 {
   const QgsAttributes& attrs = feature.attributes();
+  QVariant value;
   if ( mAttrNum < 0 || mAttrNum >= attrs.count() )
   {
-    QgsDebugMsg( "attribute required by renderer not found: " + mAttrName + "(index " + QString::number( mAttrNum ) + ")" );
-    return NULL;
+      value = mExpression->evaluate( &feature );
+  }
+  else
+  {
+      value = attrs[mAttrNum];
   }
 
   // Null values should not be categorized
-  if ( attrs[mAttrNum].isNull() )
+  if ( value.isNull() )
     return NULL;
 
   // find the right category
-  QgsSymbolV2* symbol = symbolForValue( attrs[mAttrNum].toDouble() );
+  QgsSymbolV2* symbol = symbolForValue( value.toDouble() );
   if ( symbol == NULL )
     return NULL;
 
@@ -237,6 +241,12 @@ void QgsGraduatedSymbolRendererV2::startRender( QgsRenderContext& context, const
   // find out classification attribute index from name
   mAttrNum = vlayer ? vlayer->fieldNameIndex( mAttrName ) : -1;
 
+  if ( mAttrNum == -1 )
+  {
+      mExpression = new QgsExpression( mAttrName );
+      mExpression->prepare( vlayer->pendingFields() );
+  }
+
   mRotationFieldIdx  = ( mRotationField.isEmpty()  ? -1 : vlayer->fieldNameIndex( mRotationField ) );
   mSizeScaleFieldIdx = ( mSizeScaleField.isEmpty() ? -1 : vlayer->fieldNameIndex( mSizeScaleField ) );
 
@@ -279,7 +289,11 @@ void QgsGraduatedSymbolRendererV2::stopRender( QgsRenderContext& context )
 QList<QString> QgsGraduatedSymbolRendererV2::usedAttributes()
 {
   QSet<QString> attributes;
-  attributes.insert( mAttrName );
+  QgsExpression exp( mAttrName );
+  foreach (QString attr, exp.referencedColumns() )
+  {
+      attributes << attr;
+  }
   if ( !mRotationField.isEmpty() )
   {
     attributes.insert( mRotationField );
@@ -780,11 +794,29 @@ QgsGraduatedSymbolRendererV2* QgsGraduatedSymbolRendererV2::createRenderer(
     return NULL;
 
   int attrNum = vlayer->fieldNameIndex( attrName );
+  double minimum;
+  double maximum;
+  if ( attrNum == -1 )
+  {
+      QList<double> values;
+      QgsFeatureIterator fit = vlayer->getFeatures();
+      QgsFeature feature;
+      QgsExpression expression( attrName );
+      while ( fit.nextFeature( feature ) )
+      {
+          values << expression.evaluate( feature ).toDouble();
+      }
+      qSort( values );
+      minimum = values.first();
+      maximum = values.last();
+  }
+  else
+  {
+     minimum = vlayer->minimumValue( attrNum ).toDouble();
+     maximum = vlayer->maximumValue( attrNum ).toDouble();
+  }
 
-  double minimum = vlayer->minimumValue( attrNum ).toDouble();
-  double maximum = vlayer->maximumValue( attrNum ).toDouble();
   QgsDebugMsg( QString( "min %1 // max %2" ).arg( minimum ).arg( maximum ) );
-
   QList<double> breaks;
   QList<int> labels;
   if ( mode == EqualInterval )

src/core/symbology-ng/qgsgraduatedsymbolrendererv2.h

@@ -17,6 +17,7 @@
 
 #include "qgssymbolv2.h"
 #include "qgsrendererv2.h"
+#include "qgsexpression.h"
 
 class CORE_EXPORT QgsRendererRangeV2
 {
@@ -177,7 +178,7 @@ class CORE_EXPORT QgsGraduatedSymbolRendererV2 : public QgsFeatureRendererV2
     QString mRotationField;
     QString mSizeScaleField;
     QgsSymbolV2::ScaleMethod mScaleMethod;
-
+    QgsExpression* mExpression;
     //! attribute index (derived from attribute name in startRender)
     int mAttrNum;
     int mRotationFieldIdx, mSizeScaleFieldIdx;

src/gui/symbology-ng/qgscategorizedsymbolrendererv2widget.cpp

@@ -23,10 +23,12 @@
 #include "qgsstylev2.h"
 
 #include "qgssymbolv2selectordialog.h"
+#include "qgsexpressionbuilderdialog.h"
 
 #include "qgsvectorlayer.h"
 
 #include "qgsproject.h"
+#include "qgsexpression.h"
 
 #include <QMenu>
 #include <QMessageBox>
@@ -387,6 +389,7 @@ QgsCategorizedSymbolRendererV2Widget::QgsCategorizedSymbolRendererV2Widget( QgsV
   connect( btnDeleteAllCategories, SIGNAL( clicked() ), this, SLOT( deleteAllCategories() ) );
   connect( btnAddCategory, SIGNAL( clicked() ), this, SLOT( addCategory() ) );
 
+  connect( btnExpression, SIGNAL( clicked() ), this, SLOT( setExpression() ) );
   // update GUI from renderer
   updateUiFromRenderer();
 
@@ -420,7 +423,12 @@ void QgsCategorizedSymbolRendererV2Widget::updateUiFromRenderer()
   QString attrName = mRenderer->classAttribute();
   mOldClassificationAttribute = attrName;
   int idx = cboCategorizedColumn->findText( attrName, Qt::MatchExactly );
-  cboCategorizedColumn->setCurrentIndex( idx >= 0 ? idx : 0 );
+  if ( idx == -1 )
+  {
+      cboCategorizedColumn->addItem( attrName );
+      idx = cboCategorizedColumn->count() - 1;
+  }
+  cboCategorizedColumn->setCurrentIndex( idx );
   connect( cboCategorizedColumn, SIGNAL( currentIndexChanged( int ) ), this, SLOT( categoryColumnChanged() ) );
 
   // set source symbol
@@ -590,7 +598,25 @@ void QgsCategorizedSymbolRendererV2Widget::addCategories()
   QString attrName = cboCategorizedColumn->currentText();
   int idx = mLayer->fieldNameIndex( attrName );
   QList<QVariant> unique_vals;
-  mLayer->uniqueValues( idx, unique_vals );
+  if ( idx == -1 )
+  {
+     // Lets assume it's an expression
+     QgsExpression* expression = new QgsExpression( attrName );
+     expression->prepare( mLayer->pendingFields() );
+     QgsFeatureIterator fit = mLayer->getFeatures();
+     QgsFeature feature;
+     while ( fit.nextFeature( feature ) )
+     {
+        QVariant value = expression->evaluate( feature ) ;
+        if ( unique_vals.contains( value ) )
+             continue;
+        unique_vals << value;
+     }
+  }
+  else
+  {
+      mLayer->uniqueValues( idx, unique_vals );
+  }
 
   // ask to abort if too many classes
   if ( unique_vals.size() >= 1000 )
@@ -733,6 +759,22 @@ void QgsCategorizedSymbolRendererV2Widget::deleteAllCategories()
   mModel->removeAllRows();
 }
 
+void QgsCategorizedSymbolRendererV2Widget::setExpression()
+{
+    QgsExpressionBuilderDialog dlg( mLayer, cboCategorizedColumn->currentText(), this );
+    dlg.setWindowTitle( "Set column expression" );
+    if ( dlg.exec() )
+    {
+        QString expression = dlg.expressionText();
+        if ( !expression.isEmpty() )
+        {
+            cboCategorizedColumn->addItem( expression );
+            cboCategorizedColumn->setCurrentIndex( cboCategorizedColumn->count() - 1 );
+        }
+    }
+
+}
+
 void QgsCategorizedSymbolRendererV2Widget::addCategory()
 {
   if ( !mModel ) return;

src/gui/symbology-ng/qgscategorizedsymbolrendererv2widget.h

@@ -86,6 +86,7 @@ class GUI_EXPORT QgsCategorizedSymbolRendererV2Widget : public QgsRendererV2Widg
     void addCategories();
     void deleteCategories();
     void deleteAllCategories();
+    void setExpression();
 
     void rotationFieldChanged( QString fldName );
     void sizeScaleFieldChanged( QString fldName );

src/gui/symbology-ng/qgsgraduatedsymbolrendererv2widget.cpp

@@ -22,6 +22,7 @@
 #include "qgsvectorlayer.h"
 
 #include "qgssymbolv2selectordialog.h"
+#include "qgsexpressionbuilderdialog.h"
 
 #include "qgsludialog.h"
 
@@ -359,6 +360,7 @@ QgsGraduatedSymbolRendererV2Widget::QgsGraduatedSymbolRendererV2Widget( QgsVecto
   mGraduatedSymbol = QgsSymbolV2::defaultSymbol( mLayer->geometryType() );
 
   connect( cboGraduatedColumn, SIGNAL( currentIndexChanged( int ) ), this, SLOT( graduatedColumnChanged() ) );
+  connect( btnExpression, SIGNAL( clicked() ), this, SLOT( setExpression() ) );
   connect( viewGraduated, SIGNAL( doubleClicked( const QModelIndex & ) ), this, SLOT( rangesDoubleClicked( const QModelIndex & ) ) );
   connect( viewGraduated, SIGNAL( clicked( const QModelIndex & ) ), this, SLOT( rangesClicked( const QModelIndex & ) ) );
   connect( viewGraduated, SIGNAL( customContextMenuRequested( const QPoint& ) ),  this, SLOT( contextMenuViewCategories( const QPoint& ) ) );
@@ -417,7 +419,12 @@ void QgsGraduatedSymbolRendererV2Widget::updateUiFromRenderer()
   disconnect( cboGraduatedColumn, SIGNAL( currentIndexChanged( int ) ), this, SLOT( graduatedColumnChanged() ) );
   QString attrName = mRenderer->classAttribute();
   int idx = cboGraduatedColumn->findText( attrName, Qt::MatchExactly );
-  cboGraduatedColumn->setCurrentIndex( idx >= 0 ? idx : 0 );
+  if ( idx == -1 )
+  {
+      cboGraduatedColumn->addItem( attrName );
+      idx = cboGraduatedColumn->count() - 1;
+  }
+  cboGraduatedColumn->setCurrentIndex( idx );
   connect( cboGraduatedColumn, SIGNAL( currentIndexChanged( int ) ), this, SLOT( graduatedColumnChanged() ) );
 
   // set source symbol
@@ -453,6 +460,22 @@ void QgsGraduatedSymbolRendererV2Widget::graduatedColumnChanged()
 }
 
 
+void QgsGraduatedSymbolRendererV2Widget::setExpression()
+{
+    QgsExpressionBuilderDialog dlg( mLayer, cboGraduatedColumn->currentText(), this );
+    dlg.setWindowTitle( "Set column expression" );
+    if ( dlg.exec() )
+    {
+        QString expression = dlg.expressionText();
+        if ( !expression.isEmpty() )
+        {
+            cboGraduatedColumn->addItem( expression );
+            cboGraduatedColumn->setCurrentIndex( cboGraduatedColumn->count() - 1 );
+        }
+    }
+
+}
+
 void QgsGraduatedSymbolRendererV2Widget::classifyGraduated()
 {
   QString attrName = cboGraduatedColumn->currentText();

src/gui/symbology-ng/qgsgraduatedsymbolrendererv2widget.h

@@ -80,6 +80,7 @@ class GUI_EXPORT QgsGraduatedSymbolRendererV2Widget : public QgsRendererV2Widget
   public slots:
     void changeGraduatedSymbol();
     void graduatedColumnChanged();
+    void setExpression();
     void classifyGraduated();
     void reapplyColorRamp();
     void rangesDoubleClicked( const QModelIndex & idx );

src/ui/qgscategorizedsymbolrendererv2widget.ui

@@ -31,6 +31,32 @@
          <verstretch>0</verstretch>
         </sizepolicy>
        </property>
+       <property name="maximumSize">
+        <size>
+         <width>300</width>
+         <height>16777215</height>
+        </size>
+       </property>
+       <property name="editable">
+        <bool>true</bool>
+       </property>
+      </widget>
+     </item>
+     <item>
+      <widget class="QPushButton" name="btnExpression">
+       <property name="text">
+        <string/>
+       </property>
+       <property name="icon">
+        <iconset resource="../../images/images.qrc">
+         <normaloff>:/images/themes/default/mIconExpressionEditorOpen.svg</normaloff>:/images/themes/default/mIconExpressionEditorOpen.svg</iconset>
+       </property>
+       <property name="iconSize">
+        <size>
+         <width>24</width>
+         <height>16</height>
+        </size>
+       </property>
       </widget>
      </item>
      <item>
@@ -207,6 +233,8 @@
   <tabstop>btnDeleteAllCategories</tabstop>
   <tabstop>btnJoinCategories</tabstop>
  </tabstops>
- <resources/>
+ <resources>
+  <include location="../../images/images.qrc"/>
+ </resources>
  <connections/>
 </ui>