[layouts] Add API to retrieve an expression context scope for a parti…

…cular table cell, add backend support for QgsProperty based values in a manual text table
qgis · Jul 14, 2020 · 1878f2e · 1878f2e
1 parent 59a7bb6
commit 1878f2e
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Showing 9 changed files with 163 additions and 11 deletions.
diff --git a/python/core/auto_generated/layout/qgslayoutitemattributetable.sip.in b/python/core/auto_generated/layout/qgslayoutitemattributetable.sip.in
@@ -291,6 +291,8 @@ be replaced by a line break.
 
     virtual QgsConditionalStyle conditionalCellStyle( int row, int column ) const;
 
+    virtual QgsExpressionContextScope *scopeForCell( int row, int column ) const /Factory/;
+
 
     virtual QgsExpressionContext createExpressionContext() const;
 

diff --git a/python/core/auto_generated/layout/qgslayouttable.sip.in b/python/core/auto_generated/layout/qgslayouttable.sip.in
@@ -595,6 +595,13 @@ Fetches the contents used for the cells in the table.
 Returns the conditional style to use for the cell at ``row``, ``column``.
 
 .. versionadded:: 3.12
+%End
+
+    virtual QgsExpressionContextScope *scopeForCell( int row, int column ) const /Factory/;
+%Docstring
+Creates a new QgsExpressionContextScope for the cell at ``row``, ``column``.
+
+.. versionadded:: 3.16
 %End
 
     QgsLayoutTableContents &contents();

diff --git a/src/core/layout/qgslayoutitemattributetable.cpp b/src/core/layout/qgslayoutitemattributetable.cpp
@@ -486,8 +486,9 @@ bool QgsLayoutItemAttributeTable::getTableContents( QgsLayoutTableContents &cont
   QgsFeatureIterator fit = layer->getFeatures( req );
 
   mConditionalStyles.clear();
+  mFeatures.clear();
 
-  QVector< QVector< QPair< QVariant, QgsConditionalStyle > > > tempContents;
+  QVector< QVector< Cell > > tempContents;
   QgsLayoutTableContents existingContents;
 
   while ( fit.nextFeature( f ) && counter < mMaximumNumberOfFeatures )
@@ -539,7 +540,7 @@ bool QgsLayoutItemAttributeTable::getTableContents( QgsLayoutTableContents &cont
     // correctly when this occurs
     // We also need a list of just the cell contents, so that we can do a quick check for row uniqueness (when the
     // corresponding option is enabled)
-    QVector< QPair< QVariant, QgsConditionalStyle > > currentRow;
+    QVector< Cell > currentRow;
     currentRow.reserve( mColumns.count() );
     QgsLayoutTableRow rowContents;
     rowContents.reserve( mColumns.count() );
@@ -563,7 +564,7 @@ bool QgsLayoutItemAttributeTable::getTableContents( QgsLayoutTableContents &cont
         }
 
         QVariant v = replaceWrapChar( val );
-        currentRow << qMakePair( v, style );
+        currentRow << Cell( v, style, f );
         rowContents << v;
       }
       else
@@ -574,7 +575,7 @@ bool QgsLayoutItemAttributeTable::getTableContents( QgsLayoutTableContents &cont
         expression->prepare( &context );
         QVariant value = expression->evaluate( &context );
 
-        currentRow << qMakePair( value, rowStyle );
+        currentRow << Cell( value, rowStyle, f );
         rowContents << value;
       }
     }
@@ -593,6 +594,7 @@ bool QgsLayoutItemAttributeTable::getTableContents( QgsLayoutTableContents &cont
   // build final table contents
   contents.reserve( tempContents.size() );
   mConditionalStyles.reserve( tempContents.size() );
+  mFeatures.reserve( tempContents.size() );
   for ( auto it = tempContents.constBegin(); it != tempContents.constEnd(); ++it )
   {
     QgsLayoutTableRow row;
@@ -602,8 +604,10 @@ bool QgsLayoutItemAttributeTable::getTableContents( QgsLayoutTableContents &cont
 
     for ( auto cellIt = it->constBegin(); cellIt != it->constEnd(); ++cellIt )
     {
-      row << cellIt->first;
-      rowStyles << cellIt->second;
+      row << cellIt->content;
+      rowStyles << cellIt->style;
+      if ( cellIt == it->constBegin() )
+        mFeatures << cellIt->feature;
     }
     contents << row;
     mConditionalStyles << rowStyles;
@@ -621,6 +625,14 @@ QgsConditionalStyle QgsLayoutItemAttributeTable::conditionalCellStyle( int row,
   return mConditionalStyles.at( row ).at( column );
 }
 
+QgsExpressionContextScope *QgsLayoutItemAttributeTable::scopeForCell( int row, int column ) const
+{
+  std::unique_ptr< QgsExpressionContextScope >scope( QgsLayoutTable::scopeForCell( row, column ) );
+  scope->setFeature( mFeatures.value( row ) );
+  scope->setFields( scope->feature().fields() );
+  return scope.release();
+}
+
 QgsExpressionContext QgsLayoutItemAttributeTable::createExpressionContext() const
 {
   QgsExpressionContext context = QgsLayoutTable::createExpressionContext();

diff --git a/src/core/layout/qgslayoutitemattributetable.h b/src/core/layout/qgslayoutitemattributetable.h
@@ -280,6 +280,7 @@ class CORE_EXPORT QgsLayoutItemAttributeTable: public QgsLayoutTable
     bool getTableContents( QgsLayoutTableContents &contents ) override SIP_SKIP;
 
     QgsConditionalStyle conditionalCellStyle( int row, int column ) const override;
+    QgsExpressionContextScope *scopeForCell( int row, int column ) const override SIP_FACTORY;
 
     QgsExpressionContext createExpressionContext() const override;
     void finalizeRestoreFromXml() override;
@@ -356,6 +357,18 @@ class CORE_EXPORT QgsLayoutItemAttributeTable: public QgsLayoutTable
     bool mUseConditionalStyling = false;
 
     QList< QList< QgsConditionalStyle > > mConditionalStyles;
+    QList< QgsFeature > mFeatures;
+
+    struct Cell
+    {
+      Cell( const QVariant &content, const QgsConditionalStyle &style, const QgsFeature &feature )
+        : content( content )
+        , style( style )
+        , feature( feature ) {}
+      QVariant content;
+      QgsConditionalStyle style;
+      QgsFeature feature;
+    };
 
     /**
      * Returns a list of attribute indices corresponding to displayed fields in the table.

diff --git a/src/core/layout/qgslayoutitemmanualtable.cpp b/src/core/layout/qgslayoutitemmanualtable.cpp
@@ -21,6 +21,7 @@
 #include "qgslayouttablecolumn.h"
 #include "qgsnumericformat.h"
 #include "qgsxmlutils.h"
+#include "qgsexpressioncontextutils.h"
 
 //
 // QgsLayoutItemManualTable
@@ -63,25 +64,38 @@ bool QgsLayoutItemManualTable::getTableContents( QgsLayoutTableContents &content
 
   QgsNumericFormatContext numericContext;
 
+  QgsExpressionContext context = createExpressionContext();
+
+  int rowNumber = 0;
   for ( const QgsTableRow &row : qgis::as_const( mContents ) )
   {
     QgsLayoutTableRow currentRow;
 
-    for ( int i = 0; i < mColumns.count(); ++i )
+    for ( int columnNumber = 0; columnNumber < mColumns.count(); ++columnNumber )
     {
-      if ( i < row.count() )
+      if ( columnNumber < row.count() )
       {
-        if ( row.at( i ).numericFormat() )
-          currentRow << row.at( i ).numericFormat()->formatDouble( row.at( i ).content().toDouble(), numericContext );
+        QVariant cellContent = row.at( columnNumber ).content();
+
+        if ( cellContent.canConvert< QgsProperty >() )
+        {
+          // expression based cell content, evaluate now
+          QgsExpressionContextScopePopper popper( context, scopeForCell( rowNumber, columnNumber ) );
+          cellContent = cellContent.value< QgsProperty >().value( context );
+        }
+
+        if ( row.at( columnNumber ).numericFormat() )
+          currentRow << row.at( columnNumber ).numericFormat()->formatDouble( cellContent.toDouble(), numericContext );
         else
-          currentRow << row.at( i ).content().toString();
+          currentRow << cellContent.toString();
       }
       else
       {
         currentRow << QString();
       }
     }
     contents << currentRow;
+    rowNumber++;
   }
 
   recalculateTableSize();

diff --git a/src/core/layout/qgslayouttable.cpp b/src/core/layout/qgslayouttable.cpp
@@ -989,6 +989,14 @@ QMap<int, QString> QgsLayoutTable::headerLabels() const
   return headers;
 }
 
+QgsExpressionContextScope *QgsLayoutTable::scopeForCell( int row, int column ) const
+{
+  std::unique_ptr< QgsExpressionContextScope > cellScope = qgis::make_unique< QgsExpressionContextScope >();
+  cellScope->setVariable( QStringLiteral( "table_row" ), row + 1, true );
+  cellScope->setVariable( QStringLiteral( "table_column" ), column + 1, true );
+  return cellScope.release();
+}
+
 QgsConditionalStyle QgsLayoutTable::conditionalCellStyle( int, int ) const
 {
   return QgsConditionalStyle();

diff --git a/src/core/layout/qgslayouttable.h b/src/core/layout/qgslayouttable.h
@@ -537,6 +537,13 @@ class CORE_EXPORT QgsLayoutTable: public QgsLayoutMultiFrame
      */
     virtual QgsConditionalStyle conditionalCellStyle( int row, int column ) const;
 
+    /**
+     * Creates a new QgsExpressionContextScope for the cell at \a row, \a column.
+     *
+     * \since QGIS 3.16
+     */
+    virtual QgsExpressionContextScope *scopeForCell( int row, int column ) const SIP_FACTORY;
+
     /**
      * Returns the current contents of the table. Excludes header cells.
      */

diff --git a/tests/src/core/testqgslayoutmanualtable.cpp b/tests/src/core/testqgslayoutmanualtable.cpp
@@ -44,6 +44,8 @@ class TestQgsLayoutManualTable : public QObject
     void cleanup();// will be called after every testfunction.
 
     void setContents();
+    void scopeForCell();
+    void expressionContents();
     void cellStyles();
     void cellFormat();
     void rowHeight();
@@ -270,6 +272,62 @@ void TestQgsLayoutManualTable::setContents()
   QCOMPARE( tableFromXml->columnWidths(), QList< double >() << 15.5 << 14.0 << 13.4 );
 }
 
+void TestQgsLayoutManualTable::scopeForCell()
+{
+  QVector<QStringList> expectedRows;
+
+  QgsPrintLayout l( QgsProject::instance() );
+  l.initializeDefaults();
+  l.setName( QStringLiteral( "my layout" ) );
+  QgsLayoutItemManualTable *table = new QgsLayoutItemManualTable( &l );
+
+  std::unique_ptr< QgsExpressionContextScope > scope( table->scopeForCell( 1, 2 ) );
+
+  // variable values for row/col should start at 1, not 0!
+  QCOMPARE( scope->variable( QStringLiteral( "table_row" ) ).toInt(), 2 );
+  QCOMPARE( scope->variable( QStringLiteral( "table_column" ) ).toInt(), 3 );
+}
+
+void TestQgsLayoutManualTable::expressionContents()
+{
+  QVector<QStringList> expectedRows;
+
+  QgsPrintLayout l( QgsProject::instance() );
+  l.initializeDefaults();
+  l.setName( QStringLiteral( "my layout" ) );
+  QgsLayoutItemManualTable *table = new QgsLayoutItemManualTable( &l );
+
+  QStringList row;
+
+  // 2 x 3
+  row << QStringLiteral( "Jet" ) << QStringLiteral( "1,2" ) << QStringLiteral( "1,3" );
+  expectedRows.append( row );
+  row.clear();
+  row << QStringLiteral( "my layout" ) << QStringLiteral( "Helicopter" ) << QStringLiteral( "Plane" );
+  expectedRows.append( row );
+
+  table->setTableContents(
+    QgsTableContents() << ( QgsTableRow() << QgsTableCell( QStringLiteral( "Jet" ) ) << QgsTableCell( QgsProperty::fromExpression( QStringLiteral( "@table_row  || ',' || @table_column" ) ) ) << QgsTableCell( QgsProperty::fromExpression( QStringLiteral( "@table_row  || ',' || @table_column" ) ) ) )
+    << ( QgsTableRow() << QgsTableCell( QgsProperty::fromExpression( QStringLiteral( "@layout_name" ) ) ) << QgsTableCell( QStringLiteral( "Helicopter" ) ) << QgsTableCell( QStringLiteral( "Plane" ) ) ) );
+  compareTable( table, expectedRows );
+
+  // save and restore
+
+  //write to XML
+  QDomImplementation DomImplementation;
+  QDomDocumentType documentType =
+    DomImplementation.createDocumentType(
+      QStringLiteral( "qgis" ), QStringLiteral( "http://mrcc.com/qgis.dtd" ), QStringLiteral( "SYSTEM" ) );
+  QDomDocument doc( documentType );
+  QDomElement tableElement = doc.createElement( QStringLiteral( "table" ) );
+  QVERIFY( table->writeXml( tableElement, doc, QgsReadWriteContext(), true ) );
+
+  //read from XML
+  QgsLayoutItemManualTable *tableFromXml = new QgsLayoutItemManualTable( &l );
+  QVERIFY( tableFromXml->readXml( tableElement.firstChildElement(), doc, QgsReadWriteContext(), true ) );
+  compareTable( tableFromXml, expectedRows );
+}
+
 void TestQgsLayoutManualTable::cellStyles()
 {
   QgsLayout l( QgsProject::instance() );

diff --git a/tests/src/core/testqgslayouttable.cpp b/tests/src/core/testqgslayouttable.cpp
@@ -82,6 +82,7 @@ class TestQgsLayoutTable : public QObject
     void wrappedText();
     void testBaseSort();
     void testExpressionSort();
+    void testScopeForCell();
 
   private:
     QgsVectorLayer *mVectorLayer = nullptr;
@@ -1639,5 +1640,35 @@ void TestQgsLayoutTable::testExpressionSort()
   compareTable( table, expectedRows );
 }
 
+void TestQgsLayoutTable::testScopeForCell()
+{
+  QgsLayout l( QgsProject::instance() );
+  l.initializeDefaults();
+  QgsLayoutItemAttributeTable *table = new QgsLayoutItemAttributeTable( &l );
+  table->setVectorLayer( mVectorLayer );
+  table->refresh();
+
+  std::unique_ptr< QgsExpressionContextScope > scope( table->scopeForCell( 0, 0 ) );
+
+  // variable values for row/col should start at 1, not 0!
+  QCOMPARE( scope->variable( QStringLiteral( "table_row" ) ).toInt(), 1 );
+  QCOMPARE( scope->variable( QStringLiteral( "table_column" ) ).toInt(), 1 );
+  QCOMPARE( scope->feature().attribute( 0 ).toString(), QStringLiteral( "Jet" ) );
+  scope.reset( table->scopeForCell( 0, 1 ) );
+  QCOMPARE( scope->variable( QStringLiteral( "table_row" ) ).toInt(), 1 );
+  QCOMPARE( scope->variable( QStringLiteral( "table_column" ) ).toInt(), 2 );
+  QCOMPARE( scope->feature().attribute( 0 ).toString(), QStringLiteral( "Jet" ) );
+  scope.reset( table->scopeForCell( 1, 2 ) );
+  QCOMPARE( scope->variable( QStringLiteral( "table_row" ) ).toInt(), 2 );
+  QCOMPARE( scope->variable( QStringLiteral( "table_column" ) ).toInt(), 3 );
+  QCOMPARE( scope->feature().attribute( 0 ).toString(), QStringLiteral( "Biplane" ) );
+
+  // make sure fields are set
+  QgsExpressionContext context;
+  context.appendScope( scope.release() );
+  QCOMPARE( context.fields().size(), 6 );
+  QCOMPARE( context.fields().at( 0 ).name(), QStringLiteral( "Class" ) );
+}
+
 QGSTEST_MAIN( TestQgsLayoutTable )
 #include "testqgslayouttable.moc"