Port field calculator to contexts

nyalldawson · nyalldawson · commit c1adf623afb1 · 2015-08-22T19:01:39.000+10:00
diff --git a/python/core/qgsexpression.sip b/python/core/qgsexpression.sip
@@ -77,9 +77,9 @@ class QgsExpression
     void setEvalErrorString( const QString& str );
 
     //! Set the number for $rownum special column
-    void setCurrentRowNumber( int rowNumber );
+    void setCurrentRowNumber( int rowNumber ) /Deprecated/;
     //! Return the number used for $rownum special column
-    int currentRowNumber();
+    int currentRowNumber() /Deprecated/;
 
     //! Assign a special column
     static void setSpecialColumn( const QString& name, QVariant value );
diff --git a/src/app/qgsfieldcalculator.cpp b/src/app/qgsfieldcalculator.cpp
@@ -21,6 +21,7 @@
 #include "qgsproject.h"
 #include "qgsvectordataprovider.h"
 #include "qgsvectorlayer.h"
+#include "qgsexpressioncontext.h"
 
 #include <QMessageBox>
 #include <QSettings>
@@ -147,12 +148,16 @@ void QgsFieldCalculator::accept()
   myDa.setEllipsoidalMode( QgisApp::instance()->mapCanvas()->mapSettings().hasCrsTransformEnabled() );
   myDa.setEllipsoid( QgsProject::instance()->readEntry( "Measure", "/Ellipsoid", GEO_NONE ) );
 
-
   QString calcString = builder->expressionText();
   QgsExpression exp( calcString );
   exp.setGeomCalculator( myDa );
 
-  if ( ! exp.prepare( mVectorLayer->fields() ) )
+  QgsExpressionContext expContext;
+  expContext << QgsExpressionContextUtils::globalScope()
+  << QgsExpressionContextUtils::projectScope()
+  << QgsExpressionContextUtils::layerScope( mVectorLayer );
+
+  if ( !exp.prepare( &expContext ) )
   {
     QMessageBox::critical( 0, tr( "Evaluation error" ), exp.evalErrorString() );
     return;
@@ -209,7 +214,9 @@ void QgsFieldCalculator::accept()
         }
       }
 
-      if ( ! exp.prepare( mVectorLayer->fields() ) )
+      //update expression context with new fields
+      expContext.setFields( mVectorLayer->fields() );
+      if ( ! exp.prepare( &expContext ) )
       {
         QApplication::restoreOverrideCursor();
         QMessageBox::critical( 0, tr( "Evaluation error" ), exp.evalErrorString() );
@@ -252,8 +259,11 @@ void QgsFieldCalculator::accept()
           continue;
         }
       }
-      exp.setCurrentRowNumber( rownum );
-      QVariant value = exp.evaluate( &feature );
+
+      expContext.setFeature( feature );
+      expContext.lastScope()->setVariable( QString( "_rownum_" ), rownum );
+
+      QVariant value = exp.evaluate( &expContext );
       field.convertCompatible( value );
       if ( exp.hasEvalError() )
       {
diff --git a/src/core/qgsexpression.cpp b/src/core/qgsexpression.cpp
@@ -848,9 +848,15 @@ static QVariant fcnSubstr( const QVariantList& values, const QgsExpressionContex
   return QVariant( str.mid( from -1, len ) );
 }
 
-static QVariant fcnRowNumber( const QVariantList&, const QgsExpressionContext*, QgsExpression* parent )
+static QVariant fcnRowNumber( const QVariantList&, const QgsExpressionContext* context, QgsExpression* parent )
 {
+  if ( context && context->hasVariable( "_rownum_" ) )
+    return context->variable( "_rownum_" );
+
+  Q_NOWARN_DEPRECATED_PUSH
   return QVariant( parent->currentRowNumber() );
+  Q_NOWARN_DEPRECATED_POP
+  //when above is removed - return QVariant()
 }
 
 #define FEAT_FROM_CONTEXT(c, f) if (!c || !c->hasVariable(QgsExpressionContext::EXPR_FEATURE)) return QVariant(); \
diff --git a/src/core/qgsexpression.h b/src/core/qgsexpression.h
@@ -162,9 +162,9 @@ class CORE_EXPORT QgsExpression
     void setEvalErrorString( const QString& str ) { mEvalErrorString = str; }
 
     //! Set the number for $rownum special column
-    void setCurrentRowNumber( int rowNumber ) { mRowNumber = rowNumber; }
+    Q_DECL_DEPRECATED void setCurrentRowNumber( int rowNumber ) { mRowNumber = rowNumber; }
     //! Return the number used for $rownum special column
-    int currentRowNumber() { return mRowNumber; }
+    Q_DECL_DEPRECATED int currentRowNumber() { return mRowNumber; }
 
     //! Assign a special column
     static void setSpecialColumn( const QString& name, QVariant value );

Original file line number	Diff line number	Diff line change
`@@ -848,9 +848,15 @@ static QVariant fcnSubstr( const QVariantList& values, const QgsExpressionContex`
`848`	`848`	`return QVariant( str.mid( from -1, len ) );`
`849`	`849`	`}`
`850`	`850`
`851`		`-static QVariant fcnRowNumber( const QVariantList&, const QgsExpressionContext, QgsExpression parent )`
	`851`	`+static QVariant fcnRowNumber( const QVariantList&, const QgsExpressionContext* context, QgsExpression* parent )`
`852`	`852`	`{`
	`853`	`+ if ( context && context->hasVariable( "_rownum_" ) )`
	`854`	`+ return context->variable( "_rownum_" );`
	`855`	`+`
	`856`	`+ Q_NOWARN_DEPRECATED_PUSH`
`853`	`857`	`return QVariant( parent->currentRowNumber() );`
	`858`	`+ Q_NOWARN_DEPRECATED_POP`
	`859`	`+ //when above is removed - return QVariant()`
`854`	`860`	`}`
`855`	`861`
`856`	`862`	`#define FEAT_FROM_CONTEXT(c, f) if (!c \|\| !c->hasVariable(QgsExpressionContext::EXPR_FEATURE)) return QVariant(); \`