[needs-docs] Rename map_layers_ids to map_layer_ids

It's more natural grammar

Author: nyalldawson

src/core/expression/qgsexpression.cpp

@@ -743,6 +743,8 @@ void QgsExpression::initVariableHelp()
   sVariableHelpTexts.insert( QStringLiteral( "map_crs" ), QCoreApplication::translate( "variable_help", "Coordinate reference system of map (e.g., 'EPSG:4326')." ) );
   sVariableHelpTexts.insert( QStringLiteral( "map_crs_definition" ), QCoreApplication::translate( "variable_help", "Coordinate reference system of map (full definition)." ) );
   sVariableHelpTexts.insert( QStringLiteral( "map_units" ), QCoreApplication::translate( "variable_help", "Units for map measurements." ) );
+  sVariableHelpTexts.insert( QStringLiteral( "map_layer_ids" ), QCoreApplication::translate( "variable_help", "List of map layer IDs visible in the map." ) );
+  sVariableHelpTexts.insert( QStringLiteral( "map_layers" ), QCoreApplication::translate( "variable_help", "List of map layers visible in the map." ) );
 
   sVariableHelpTexts.insert( QStringLiteral( "row_number" ), QCoreApplication::translate( "variable_help", "Stores the number of the current row." ) );
   sVariableHelpTexts.insert( QStringLiteral( "grid_number" ), QCoreApplication::translate( "variable_help", "Current grid annotation value." ) );

src/core/layout/qgslayoutitemmap.cpp

@@ -1157,12 +1157,12 @@ QgsExpressionContext QgsLayoutItemMap::createExpressionContext() const
 
   QVariantList layersIds;
   QVariantList layers;
-  scope->addVariable( QgsExpressionContextScope::StaticVariable( QStringLiteral( "map_layers_ids" ), layersIds, true ) );
+  scope->addVariable( QgsExpressionContextScope::StaticVariable( QStringLiteral( "map_layer_ids" ), layersIds, true ) );
   scope->addVariable( QgsExpressionContextScope::StaticVariable( QStringLiteral( "map_layers" ), layers, true ) );
 
   context.appendScope( scope );
 
-  // The scope map_layers_ids and map_layers variables have been added to the context, only now we can
+  // The scope map_layer_ids and map_layers variables have been added to the context, only now we can
   // call layersToRender (just in case layersToRender relies on evaluating an expression which uses
   // other variables contained within the map settings scope
   const QList<QgsMapLayer *> layersInMap = layersToRender( &context );
@@ -1174,7 +1174,7 @@ QgsExpressionContext QgsLayoutItemMap::createExpressionContext() const
     layersIds << layer->id();
     layers << QVariant::fromValue<QgsWeakMapLayerPointer>( QgsWeakMapLayerPointer( layer ) );
   }
-  scope->addVariable( QgsExpressionContextScope::StaticVariable( QStringLiteral( "map_layers_ids" ), layersIds, true ) );
+  scope->addVariable( QgsExpressionContextScope::StaticVariable( QStringLiteral( "map_layer_ids" ), layersIds, true ) );
   scope->addVariable( QgsExpressionContextScope::StaticVariable( QStringLiteral( "map_layers" ), layers, true ) );
 
   return context;

src/core/qgsexpressioncontext.cpp

@@ -1005,7 +1005,7 @@ QgsExpressionContextScope *QgsExpressionContextUtils::mapSettingsScope( const Qg
     layersIds << layer->id();
     layers << QVariant::fromValue<QgsWeakMapLayerPointer>( QgsWeakMapLayerPointer( layer ) );
   }
-  scope->addVariable( QgsExpressionContextScope::StaticVariable( QStringLiteral( "map_layers_ids" ), layersIds, true ) );
+  scope->addVariable( QgsExpressionContextScope::StaticVariable( QStringLiteral( "map_layer_ids" ), layersIds, true ) );
   scope->addVariable( QgsExpressionContextScope::StaticVariable( QStringLiteral( "map_layers" ), layers, true ) );
 
   scope->addFunction( QStringLiteral( "is_layer_visible" ), new GetLayerVisibility( mapSettings.layers() ) );

tests/src/core/testqgslayoutitem.cpp

@@ -1435,7 +1435,7 @@ void TestQgsLayoutItem::itemVariablesFunction()
   std::unique_ptr< QgsVectorLayer > layer = qgis::make_unique< QgsVectorLayer >( QStringLiteral( "Point?field=id_a:integer" ), QStringLiteral( "A" ), QStringLiteral( "memory" ) );
   std::unique_ptr< QgsVectorLayer > layer2 = qgis::make_unique< QgsVectorLayer >( QStringLiteral( "Point?field=id_a:integer" ), QStringLiteral( "B" ), QStringLiteral( "memory" ) );
   map->setLayers( QList<QgsMapLayer *>() << layer.get() << layer2.get() );
-  QgsExpression e5( QStringLiteral( "map_get( item_variables( 'Map_id' ), 'map_layers_ids' )" ) );
+  QgsExpression e5( QStringLiteral( "map_get( item_variables( 'Map_id' ), 'map_layer_ids' )" ) );
   r = e5.evaluate( &c );
   QCOMPARE( r.toStringList().join( ',' ), QStringLiteral( "%1,%2" ).arg( layer->id(), layer2->id() ) );
   e5 = QgsExpression( QStringLiteral( "array_foreach(map_get( item_variables( 'Map_id' ), 'map_layers' ), layer_property(@element, 'name'))" ) );