Merge pull request #3364 from nyalldawson/expression_dep

Clean QgsExpression for 3.0

doc/api_break.dox

@@ -23,6 +23,7 @@ This page tries to maintain a list with incompatible changes that happened in pr
 <table>
 <caption id="renamed_classes">Renamed classes</caption>
 <tr><th>API 2.x                          <th>API 3.X
+<tr><td>QgsAttributeAction               <td>QgsActionManager
 <tr><td>QgsColorButtonV2                 <td>QgsColorButton
 <tr><td>QgsSymbolLayerV2                 <td>QgsSymbolLayer
 <tr><td>QgsSymbolLayerV2AbstractMetadata <td>QgsSymbolLayerAbstractMetadata
@@ -127,6 +128,15 @@ corresponding counterparts in QgsUnitTypes should be used instead.</li>
 <li>fileMenu() has been removed, use projectMenu() instead.
 </ul>
 
+\subsection qgis_api_break_3_0_QgsActionManager QgsActionManager
+
+<ul>
+<li>doAction() no longer accepts a substitution map. Use expression context variables instead.</li>
+<li>The doAction() variant which takes a QgsFeature along has been removed. Use the expression context
+variant instead.</li>
+<li>expandAction() has been removed. Use QgsExpression::replaceExpressionText() instead.</li>
+</ul>
+
 \subsection qgis_api_break_3_0_QgsAtlasComposition QgsAtlasComposition
 
 <ul>
@@ -145,6 +155,15 @@ corresponding counterparts in QgsUnitTypes should be used instead.</li>
 <li>GenericDataSourceURI has been renamed to GenericDataSourceUri</li>
 </ul>
 
+\subsection qgis_api_break_3_0_QgsComposerLabel QgsComposerLabel
+
+<ul>
+<li>setExpressionContext() has been removed. Setup the composition using an atlas and with
+expression variables in the composer label item instead.</li>
+<li>setSubstitutions has been removed. Use expression context variables in the composer
+label item instead.</li>
+</ul>
+
 \subsection qgis_api_break_3_0_QgsComposerLegend QgsComposerLegend
 
 <ul>
@@ -243,6 +262,13 @@ be returned in place of a null pointer.</li>
 <li>updateCRSCache() has been renamed to updateCrsCache</li>
 </ul>
 
+\subsection qgis_api_break_3_0_QgsDataDefined QgsDataDefined
+
+<ul>
+<li>expressionParams(), setExpressionParams() and insertExpressionParam() have been removed.
+QgsExpressionContext variables should be used in their place.</li>
+</ul>
+
 \subsection qgis_api_break_3_0_QgsDataDefinedSymbolDialog QgsDataDefinedSymbolDialog
 
 <ul>
@@ -290,6 +316,27 @@ place of a null pointer.</li>
 <li>The ct member has been removed. Use coordinateTransform() and setCoordinateTransform() instead.
 </ul>
 
+\subsection qgis_api_break_3_0_QgsExpression QgsExpression
+
+<ul>
+<li>prepare( const QgsFields &fields ) has been removed. Use prepare( const QgsExpressionContext *context ) instead.</li>
+<li>The evaluate methods which accept feature parameters have been removed. Use the version which takes a QgsExpressionContext
+argument instead.</li>
+<li>isValid( const QString& text, const QgsFields& fields, QString &errorMessage ) has been removed, use the QgsExpressionContext
+version instead.</li>
+<li>setCurrentRowNumber, currentRowNumber, scale, setScale, setSpecialColumn, unsetSpecialColumn, specialColumn, hasSpecialColumn have been
+removed. Use QgsExpressionContext variables instead.</li>
+<li>The replaceExpressionText version which accepts a QgsFeature argument has been removed. Use the QgsExpressionContext
+version instead.</li>
+<li>QgsExpression::Function::func has been modified to use a QgsExpressionContext argument rather than a QgsFeature.</li>
+<li>QgsExpression::Function::usesgeometry() has been renamed to usesGeometry()</li>
+<li>QgsExpression::Function::helptext() has been renamed to helpText()</li>
+<li>The QgsExpression::Node::eval and prepare versions which take a QgsFeature has been removed, use the QgsExpressionContext versions instead.</li>
+<li>QgsExpression::Interval has been removed. Use QgsInterval instead.</li>
+<li>replaceExpressionText() no longer accepts a substitution map parameter. Use expression context variables instead.</li>
+<li>helptext() has been renamed to helpText()</li>
+</ul>
+
 \subsection qgis_api_break_3_0_QgsFeature QgsFeature
 
 <ul>

doc/qgis3_user_changes.dox

@@ -0,0 +1,24 @@
+/*! \page qgis3_user_changes QGIS 3.0 User Changes
+
+\tableofcontents
+
+Notes regarding user related changes for QGIS 3.0 which should be included in the release notes.
+
+\section qgis3_user_changes_expressions Expressions
+
+QGIS 3.0 brings some changes to the expression engine, which may require existing projects to
+be updated so that any expressions in use have the following changes:
+<ul>
+<li>$rownum has been replaced by \@row_number</li>
+<li>$scale has been replaced by \@map_scale</li>
+<li>$map has been replaced by \@map_id</li>
+<li>$numpages has been replaced by \@layout_numpages</li>
+<li>$page has been replaced by \@layout_page</li>
+<li>$feature has been replaced by \@atlas_featurenumber</li>
+<li>$atlasfeatureid has been replaced by \@atlas_featureid</li>
+<li>$atlasfeature has been replaced by \@atlas_feature</li>
+<li>$atlasgeometry has been replaced by \@atlas_geometry</li>
+<li>$numfeatures has been replaced by \@atlas_totalfeatures</li>
+</ul>
+
+*/

python/core/__init__.py

@@ -72,7 +72,10 @@ def __init__(self, func, name, args, group, helptext='', usesgeometry=True, refe
             self.function = func
             self.expandargs = expandargs
 
-        def func(self, values, feature, parent):
+        def func(self, values, context, parent):
+            feature = None
+            if context:
+                feature = context.feature()
             try:
                 if self.expandargs:
                     values.append(feature)

python/core/composer/qgscomposerlabel.sip

@@ -28,16 +28,6 @@ class QgsComposerLabel : QgsComposerItem
     /** Returns the text as it appears on screen (with replaced data field) */
     QString displayText() const;
 
-    /** Sets the current feature, the current layer and a list of local variable substitutions for evaluating expressions.
-      * @deprecated use atlas features and setSubstitutions() instead
-      */
-    void setExpressionContext( QgsFeature* feature, QgsVectorLayer* layer, const QMap<QString, QVariant>& substitutions = QMap<QString, QVariant>() ) /Deprecated/;
-
-    /** Sets the list of local variable substitutions for evaluating expressions in label text.
-     * @note added in QGIS 2.12
-     */
-    void setSubstitutions( const QMap<QString, QVariant>& substitutions = QMap<QString, QVariant>() );
-
     QFont font() const;
     void setFont( const QFont& f );
     /** Accessor for the vertical alignment of the label

python/core/core.sip

@@ -23,7 +23,6 @@
 %Include qgsaction.sip
 %Include qgsactionmanager.sip
 %Include qgsaggregatecalculator.sip
-%Include qgsattributeaction.sip
 %Include qgsattributetableconfig.sip
 %Include qgsbrowsermodel.sip
 %Include qgsclipper.sip

python/core/qgsactionmanager.sip

@@ -75,24 +75,10 @@ class QgsActionManager
      * @param index action index
      * @param feature feature to run action for
      * @param context expression context to evalute expressions under
-     * @param substitutionMap deprecated - kept for compatibility with projects, will be removed for 3.0
      */
-    // TODO QGIS 3.0 remove substition map - force use of expression variables
     void doAction( int index,
                    const QgsFeature& feature,
-                   const QgsExpressionContext& context,
-                   const QMap<QString, QVariant> *substitutionMap = nullptr );
-
-
-    /** Does the action using the expression builder to expand it
-     *  and getting values from the passed feature attribute map.
-     *  substitutionMap is used to pass custom substitutions, to replace
-     *  each key in the map with the associated value
-     *  @note available in python bindings as doActionFeatureWithSubstitution
-     */
-    void doAction( int index,
-                   const QgsFeature &feat,
-                   const QMap<QString, QVariant> *substitutionMap ) /PyName=doActionFeatureWithSubstitution/;
+                   const QgsExpressionContext& context );
 
     //! Removes all actions
     void clearActions();
@@ -103,26 +89,6 @@ class QgsActionManager
     //! Return the layer
     QgsVectorLayer* layer() const;
 
-    /** Expands the given action, replacing all %'s with the value as
-     *  given.
-     * @deprecated use QgsExpression::replaceExpressionText() instead
-     */
-    QString expandAction( QString action, const QMap<int, QVariant> &attributes, uint defaultValueIndex ) /Deprecated/;
-
-    /** Expands the given action using the expression builder
-     *  This function currently replaces each expression between [% and %]
-     *  placeholders in the action with the result of its evaluation on
-     *  the feature passed as argument.
-     *
-     *  Additional substitutions can be passed through the substitutionMap
-     *  parameter
-     *  @deprecated use QgsExpression::replaceExpressionText() instead
-     */
-    QString expandAction( const QString& action,
-                          QgsFeature &feat,
-                          const QMap<QString, QVariant> *substitutionMap = 0 ) /Deprecated/;
-
-
     //! Writes the actions out in XML format
     bool writeXml( QDomNode& layer_node, QDomDocument& doc ) const;
 

python/core/qgsdatadefined.sip

@@ -110,12 +110,6 @@ class QgsDataDefined
      */
     QString expressionOrField() const;
 
-    //! @note not available in python bindings
-    //QMap<QString, QVariant> expressionParams() const;
-    //! @note not available in python bindings
-    //void setExpressionParams( QMap<QString, QVariant> params );
-    void insertExpressionParam( const QString& key, const QVariant& param );
-
     /** Prepares the expression using a vector layer
      * @param layer vector layer
      * @returns true if expression was successfully prepared