Finish porting composer to expression contexts

python/core/composer/qgscomposerhtml.sip

@@ -185,15 +185,16 @@ class QgsComposerHtml: QgsComposerMultiFrame
     /** Reloads the html source from the url and redraws the item.
      * @param useCache set to true to use a cached copy of remote html
      * content
+     * @param context expression context for evaluating data defined urls and expressions in html
      * @see setUrl
      * @see url
      */
-    void loadHtml( const bool useCache = false );
+    void loadHtml( const bool useCache = false, const QgsExpressionContext* context = 0 );
 
     /** Recalculates the frame sizes for the current viewport dimensions*/
     void recalculateFrameSizes();
     void refreshExpressionContext();
 
-    virtual void refreshDataDefinedProperty( const QgsComposerObject::DataDefinedProperty property = QgsComposerObject::AllProperties );
+    virtual void refreshDataDefinedProperty( const QgsComposerObject::DataDefinedProperty property = QgsComposerObject::AllProperties, const QgsExpressionContext* context = 0 );
 
 };

python/core/composer/qgscomposeritem.sip

@@ -658,9 +658,10 @@ class QgsComposerItem : QgsComposerObject, QGraphicsRectItem
      * @param property data defined property to refresh. If property is set to
      * QgsComposerItem::AllProperties then all data defined properties for the item will be
      * refreshed.
+     * @param context expression context for evaluating data defined expressions
      * @note this method was added in version 2.5
     */
-    virtual void refreshDataDefinedProperty( const QgsComposerObject::DataDefinedProperty property = QgsComposerObject::AllProperties );
+    virtual void refreshDataDefinedProperty( const QgsComposerObject::DataDefinedProperty property = QgsComposerObject::AllProperties, const QgsExpressionContext* context = 0 );
 
   protected:
 
@@ -767,11 +768,12 @@ class QgsComposerItem : QgsComposerObject, QGraphicsRectItem
      * @param resizeOnly set to true if the item is only being resized. If true then
      * the position of the returned rect will be adjusted to account for the item's
      * position mode
+     * @param context expression context for evaluating data defined expressions
      * @returns bounding box rectangle for item after data defined size and position have been
      * set and position mode has been accounted for
      * @note added in QGIS 2.5
     */
-    QRectF evalItemRect( const QRectF &newRect, const bool resizeOnly = false );
+    QRectF evalItemRect( const QRectF &newRect, const bool resizeOnly = false, const QgsExpressionContext* context = 0 );
 
     /** Returns whether the item should be drawn in the current context
      * @returns true if item should be drawn

python/core/composer/qgscomposermap.sip

@@ -777,7 +777,7 @@ class QgsComposerMap : QgsComposerItem
     /** @deprecated use QgsComposerMapOverview::overviewExtentChanged instead*/
     void overviewExtentChanged();
 
-    virtual void refreshDataDefinedProperty( const QgsComposerObject::DataDefinedProperty property = QgsComposerObject::AllProperties );
+    virtual void refreshDataDefinedProperty( const QgsComposerObject::DataDefinedProperty property = QgsComposerObject::AllProperties, const QgsExpressionContext* context = 0 );
 
   protected slots:
 

python/core/composer/qgscomposerobject.sip

@@ -145,20 +145,22 @@ class QgsComposerObject : QObject
      * @param property data defined property to refresh. If property is set to
      * QgsComposerItem::AllProperties then all data defined properties for the item will be
      * refreshed.
+     * @context expression context for evaluating data defined expressions
      * @note this method was added in version 2.5
     */
-    virtual void refreshDataDefinedProperty( const DataDefinedProperty property = AllProperties );
-
+    virtual void refreshDataDefinedProperty( const DataDefinedProperty property = AllProperties, const QgsExpressionContext* context = 0 );
 
   protected:
 
     /** Evaluate a data defined property and return the calculated value
      * @returns true if data defined property could be successfully evaluated
      * @param property data defined property to evaluate
      * @param expressionValue QVariant for storing the evaluated value
+     * @param context expression context for evaluating expressions. Must have feature and fields set to current
+     * atlas feature and coverage layer fields prior to calling this method.
      * @note this method was added in version 2.5
     */
-    bool dataDefinedEvaluate( const QgsComposerObject::DataDefinedProperty property, QVariant &expressionValue ) const;
+    bool dataDefinedEvaluate( const QgsComposerObject::DataDefinedProperty property, QVariant &expressionValue, const QgsExpressionContext& context = QgsExpressionContext() ) const;
 
   signals:
     /** Emitted when the item changes. Signifies that the item widgets must update the

python/core/composer/qgscomposerpicture.sip

@@ -246,10 +246,11 @@ class QgsComposerPicture: QgsComposerItem
 
     /** Recalculates the source image (if using an expression for picture's source)
      * and reloads and redraws the picture.
+     * @param context expression context for evaluating data defined picture sources
      * @note added in 2.3
      */
-    void refreshPicture();
-
+    void refreshPicture( const QgsExpressionContext* context = 0 );
+    
     /** Prepares the picture's source expression after it is altered or the compositions
      * atlas coverage layer changes.
      * @note added in 2.3
@@ -262,7 +263,7 @@ class QgsComposerPicture: QgsComposerItem
      */
     void recalculateSize();
 
-    virtual void refreshDataDefinedProperty( const QgsComposerObject::DataDefinedProperty property = QgsComposerObject::AllProperties );
+    virtual void refreshDataDefinedProperty( const QgsComposerObject::DataDefinedProperty property = QgsComposerObject::AllProperties, const QgsExpressionContext *context = 0 );
 
   signals:
     /** Is emitted on picture rotation change*/

python/core/composer/qgscomposition.sip

@@ -673,9 +673,10 @@ class QgsComposition : QGraphicsScene
      * @param property data defined property to refresh. If property is set to
      * QgsComposerItem::AllProperties then all data defined properties for the composition will be
      * refreshed.
+     * @param context expression context for evaluating data defined expressions
      * @note this method was added in version 2.5
     */
-    void refreshDataDefinedProperty( const QgsComposerObject::DataDefinedProperty property = QgsComposerObject::AllProperties );
+    void refreshDataDefinedProperty( const QgsComposerObject::DataDefinedProperty property = QgsComposerObject::AllProperties, const QgsExpressionContext* context = 0 );
 
   protected:
     void init();

src/core/composer/qgscomposerattributetable.cpp

@@ -375,6 +375,9 @@ bool QgsComposerAttributeTable::getFeatureAttributes( QList<QgsAttributeMap> &at
     return false;
   }
 
+  QScopedPointer< QgsExpressionContext > context( createExpressionContext() );
+  context->setFields( mVectorLayer->fields() );
+
   attributeMaps.clear();
 
   //prepare filter expression
@@ -421,10 +424,11 @@ bool QgsComposerAttributeTable::getFeatureAttributes( QList<QgsAttributeMap> &at
 
   while ( fit.nextFeature( f ) && counter < mMaximumNumberOfFeatures )
   {
+    context->setFeature( f );
     //check feature against filter
     if ( activeFilter && !filterExpression.isNull() )
     {
-      QVariant result = filterExpression->evaluate( &f, mVectorLayer->fields() );
+      QVariant result = filterExpression->evaluate( context.data() );
       // skip this feature if the filter evaluation is false
       if ( !result.toBool() )
       {
@@ -447,9 +451,9 @@ bool QgsComposerAttributeTable::getFeatureAttributes( QList<QgsAttributeMap> &at
       {
         // Lets assume it's an expression
         QgsExpression* expression = new QgsExpression(( *columnIt )->attribute() );
-        expression->setCurrentRowNumber( counter + 1 );
-        expression->prepare( mVectorLayer->fields() );
-        QVariant value = expression->evaluate( f );
+        context->lastScope()->setVariable( QString( "_rownum_" ), counter + 1 );
+        expression->prepare( context.data() );
+        QVariant value = expression->evaluate( context.data() );
         attributeMaps.last().insert( i, value.toString() );
       }
 

src/core/composer/qgscomposerattributetablev2.cpp

@@ -451,6 +451,9 @@ bool QgsComposerAttributeTableV2::getTableContents( QgsComposerTableContents &co
     return false;
   }
 
+  QScopedPointer< QgsExpressionContext > context( createExpressionContext() );
+  context->setFields( layer->fields() );
+
   //prepare filter expression
   QScopedPointer<QgsExpression> filterExpression;
   bool activeFilter = false;
@@ -511,10 +514,11 @@ bool QgsComposerAttributeTableV2::getTableContents( QgsComposerTableContents &co
 
   while ( fit.nextFeature( f ) && counter < mMaximumNumberOfFeatures )
   {
+    context->setFeature( f );
     //check feature against filter
     if ( activeFilter && !filterExpression.isNull() )
     {
-      QVariant result = filterExpression->evaluate( &f, layer->fields() );
+      QVariant result = filterExpression->evaluate( context.data() );
       // skip this feature if the filter evaluation is false
       if ( !result.toBool() )
       {
@@ -551,9 +555,9 @@ bool QgsComposerAttributeTableV2::getTableContents( QgsComposerTableContents &co
       {
         // Lets assume it's an expression
         QgsExpression* expression = new QgsExpression(( *columnIt )->attribute() );
-        expression->setCurrentRowNumber( counter + 1 );
-        expression->prepare( layer->fields() );
-        QVariant value = expression->evaluate( f );
+        context->lastScope()->setVariable( QString( "_rownum_" ), counter + 1 );
+        expression->prepare( context.data() );
+        QVariant value = expression->evaluate( context.data() );
         currentRow << value;
       }
     }

src/core/composer/qgscomposerhtml.cpp

@@ -122,13 +122,21 @@ void QgsComposerHtml::setEvaluateExpressions( bool evaluateExpressions )
   emit changed();
 }
 
-void QgsComposerHtml::loadHtml( const bool useCache )
+void QgsComposerHtml::loadHtml( const bool useCache, const QgsExpressionContext *context )
 {
   if ( !mWebPage )
   {
     return;
   }
 
+  const QgsExpressionContext* evalContext = context;
+  QScopedPointer< QgsExpressionContext > scopedContext;
+  if ( !evalContext )
+  {
+    scopedContext.reset( createExpressionContext() );
+    evalContext = scopedContext.data();
+  }
+
   QString loadedHtml;
   switch ( mContentMode )
   {
@@ -139,7 +147,7 @@ void QgsComposerHtml::loadHtml( const bool useCache )
 
       //data defined url set?
       QVariant exprVal;
-      if ( dataDefinedEvaluate( QgsComposerObject::SourceUrl, exprVal ) )
+      if ( dataDefinedEvaluate( QgsComposerObject::SourceUrl, exprVal, *evalContext ) )
       {
         currentUrl = exprVal.toString().trimmed();;
         QgsDebugMsg( QString( "exprVal Source Url:%1" ).arg( currentUrl ) );
@@ -168,7 +176,7 @@ void QgsComposerHtml::loadHtml( const bool useCache )
   //evaluate expressions
   if ( mEvaluateExpressions )
   {
-    loadedHtml = QgsExpression::replaceExpressionText( loadedHtml, &mExpressionFeature, mExpressionLayer, 0, mDistanceArea );
+    loadedHtml = QgsExpression::replaceExpressionText( loadedHtml, evalContext, 0, mDistanceArea );
   }
 
   mLoaded = false;
@@ -552,12 +560,20 @@ void QgsComposerHtml::refreshExpressionContext()
   loadHtml( true );
 }
 
-void QgsComposerHtml::refreshDataDefinedProperty( const QgsComposerObject::DataDefinedProperty property )
+void QgsComposerHtml::refreshDataDefinedProperty( const QgsComposerObject::DataDefinedProperty property, const QgsExpressionContext* context )
 {
+  const QgsExpressionContext* evalContext = context;
+  QScopedPointer< QgsExpressionContext > scopedContext;
+  if ( !evalContext )
+  {
+    scopedContext.reset( createExpressionContext() );
+    evalContext = scopedContext.data();
+  }
+
   //updates data defined properties and redraws item to match
   if ( property == QgsComposerObject::SourceUrl || property == QgsComposerObject::AllProperties )
   {
-    loadHtml( true );
+    loadHtml( true, evalContext );
   }
-  QgsComposerObject::refreshDataDefinedProperty( property );
+  QgsComposerObject::refreshDataDefinedProperty( property, context );
 }

src/core/composer/qgscomposerhtml.h

@@ -210,16 +210,17 @@ class CORE_EXPORT QgsComposerHtml: public QgsComposerMultiFrame
     /** Reloads the html source from the url and redraws the item.
      * @param useCache set to true to use a cached copy of remote html
      * content
+     * @param context expression context for evaluating data defined urls and expressions in html
      * @see setUrl
      * @see url
      */
-    void loadHtml( const bool useCache = false );
+    void loadHtml( const bool useCache = false, const QgsExpressionContext* context = 0 );
 
     /** Recalculates the frame sizes for the current viewport dimensions*/
     void recalculateFrameSizes() override;
     void refreshExpressionContext();
 
-    virtual void refreshDataDefinedProperty( const QgsComposerObject::DataDefinedProperty property = QgsComposerObject::AllProperties ) override;
+    virtual void refreshDataDefinedProperty( const QgsComposerObject::DataDefinedProperty property = QgsComposerObject::AllProperties, const QgsExpressionContext* context = 0 ) override;
 
   private slots:
     void frameLoaded( bool ok = true );

src/core/composer/qgscomposeritem.cpp

@@ -897,16 +897,17 @@ void QgsComposerItem::setBlendMode( const QPainter::CompositionMode blendMode )
 {
   mBlendMode = blendMode;
   // Update the composer effect to use the new blend mode
-  refreshBlendMode();
+  QScopedPointer< QgsExpressionContext > context( createExpressionContext() );
+  refreshBlendMode( *context.data() );
 }
 
-void QgsComposerItem::refreshBlendMode()
+void QgsComposerItem::refreshBlendMode( const QgsExpressionContext& context )
 {
   QPainter::CompositionMode blendMode = mBlendMode;
 
   //data defined blend mode set?
   QVariant exprVal;
-  if ( dataDefinedEvaluate( QgsComposerObject::BlendMode, exprVal ) && !exprVal.isNull() )
+  if ( dataDefinedEvaluate( QgsComposerObject::BlendMode, exprVal, context ) && !exprVal.isNull() )
   {
     QString blendstr = exprVal.toString().trimmed();
     QPainter::CompositionMode blendModeD = QgsSymbolLayerV2Utils::decodeBlendMode( blendstr );
@@ -922,16 +923,17 @@ void QgsComposerItem::refreshBlendMode()
 void QgsComposerItem::setTransparency( const int transparency )
 {
   mTransparency = transparency;
-  refreshTransparency( true );
+  QScopedPointer< QgsExpressionContext > context( createExpressionContext() );
+  refreshTransparency( true, *context.data() );
 }
 
-void QgsComposerItem::refreshTransparency( const bool updateItem )
+void QgsComposerItem::refreshTransparency( const bool updateItem, const QgsExpressionContext& context )
 {
   int transparency = mTransparency;
 
   //data defined transparency set?
   QVariant exprVal;
-  if ( dataDefinedEvaluate( QgsComposerObject::Transparency, exprVal ) )
+  if ( dataDefinedEvaluate( QgsComposerObject::Transparency, exprVal, context ) )
   {
     bool ok;
     int transparencyD = exprVal.toInt( &ok );
@@ -1072,16 +1074,17 @@ void QgsComposerItem::setItemRotation( const double r, const bool adjustPosition
     mItemRotation = r;
   }
 
-  refreshRotation( true, adjustPosition );
+  QScopedPointer< QgsExpressionContext > context( createExpressionContext() );
+  refreshRotation( true, adjustPosition, *context.data() );
 }
 
-void QgsComposerItem::refreshRotation( const bool updateItem, const bool adjustPosition )
+void QgsComposerItem::refreshRotation( const bool updateItem, const bool adjustPosition, const QgsExpressionContext& context )
 {
   double rotation = mItemRotation;
 
   //data defined rotation set?
   QVariant exprVal;
-  if ( dataDefinedEvaluate( QgsComposerObject::ItemRotation, exprVal ) )
+  if ( dataDefinedEvaluate( QgsComposerObject::ItemRotation, exprVal, context ) )
   {
     bool ok;
     double rotD = exprVal.toDouble( &ok );
@@ -1355,38 +1358,48 @@ void QgsComposerItem::repaint()
   updateItem();
 }
 
-void QgsComposerItem::refreshDataDefinedProperty( const QgsComposerObject::DataDefinedProperty property )
+void QgsComposerItem::refreshDataDefinedProperty( const QgsComposerObject::DataDefinedProperty property, const QgsExpressionContext *context )
 {
+  //maintain 2.10 API
+  //TODO QGIS 3.0 - remove this
+  const QgsExpressionContext* evalContext = context;
+  QScopedPointer< QgsExpressionContext > scopedContext;
+  if ( !evalContext )
+  {
+    scopedContext.reset( createExpressionContext() );
+    evalContext = scopedContext.data();
+  }
+
   //update data defined properties and redraw item to match
   if ( property == QgsComposerObject::PositionX || property == QgsComposerObject::PositionY ||
        property == QgsComposerObject::ItemWidth || property == QgsComposerObject::ItemHeight ||
        property == QgsComposerObject::AllProperties )
   {
     QRectF beforeRect = QRectF( pos().x(), pos().y(), rect().width(), rect().height() );
-    QRectF evaluatedRect = evalItemRect( beforeRect );
+    QRectF evaluatedRect = evalItemRect( beforeRect, false, evalContext );
     if ( evaluatedRect != beforeRect )
     {
       setSceneRect( evaluatedRect );
     }
   }
   if ( property == QgsComposerObject::ItemRotation || property == QgsComposerObject::AllProperties )
   {
-    refreshRotation( false, true );
+    refreshRotation( false, true, *evalContext );
   }
   if ( property == QgsComposerObject::Transparency || property == QgsComposerObject::AllProperties )
   {
-    refreshTransparency( false );
+    refreshTransparency( false, *evalContext );
   }
   if ( property == QgsComposerObject::BlendMode || property == QgsComposerObject::AllProperties )
   {
-    refreshBlendMode();
+    refreshBlendMode( *evalContext );
   }
   if ( property == QgsComposerObject::ExcludeFromExports || property == QgsComposerObject::AllProperties )
   {
     bool exclude = mExcludeFromExports;
     //data defined exclude from exports set?
     QVariant exprVal;
-    if ( dataDefinedEvaluate( QgsComposerObject::ExcludeFromExports, exprVal ) && !exprVal.isNull() )
+    if ( dataDefinedEvaluate( QgsComposerObject::ExcludeFromExports, exprVal, *evalContext ) && !exprVal.isNull() )
     {
       exclude = exprVal.toBool();
     }