Make map id optional in map_credits layout function

If not specified, the credits for ALL layers from ALL maps will be collected
qgis · Apr 13, 2023 · f7a7a24 · f7a7a24
1 parent e5c2f56
commit f7a7a24
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Showing 3 changed files with 55 additions and 21 deletions.
diff --git a/resources/function_help/json/map_credits b/resources/function_help/json/map_credits
@@ -2,10 +2,11 @@
   "name": "map_credits",
   "type": "function",
   "groups": ["Layout"],
-  "description": "Returns a list of credit (usage rights) strings for the layers shown in a layout map item.",
+  "description": "Returns a list of credit (usage rights) strings for the layers shown in a layout, or specific layout map item.",
   "arguments": [{
     "arg": "id",
-    "description": "map item ID"
+    "optional": true,
+    "description": "Map item ID. If not specified, the layers from all maps in the layout will be used."
   }, {
     "arg": "include_layer_names",
     "description": "Set to true to include layer names before their credit strings",
@@ -18,6 +19,9 @@
     "default": "': '"
   }],
   "examples": [{
+    "expression": "array_to_string( map_credits() )",
+    "returns": "comma separated list of layer credits for all layers shown in all map items in the layout, e.g 'CC-BY-NC, CC-BY-SA'"
+  }, {
     "expression": "array_to_string( map_credits( 'Main Map' ) )",
     "returns": "comma separated list of layer credits for layers shown in the 'Main Map' layout item, e.g 'CC-BY-NC, CC-BY-SA'"
   }, {

diff --git a/src/core/expression/qgsexpressioncontextutils.cpp b/src/core/expression/qgsexpressioncontextutils.cpp
@@ -127,7 +127,7 @@ class GetLayoutMapLayerCredits : public QgsScopedExpressionFunction
   public:
     GetLayoutMapLayerCredits( const QgsLayout *c )
       : QgsScopedExpressionFunction( QStringLiteral( "map_credits" ),
-                                     QgsExpressionFunction::ParameterList() << QgsExpressionFunction::Parameter( QStringLiteral( "id" ) )
+                                     QgsExpressionFunction::ParameterList() << QgsExpressionFunction::Parameter( QStringLiteral( "id" ), true )
                                      << QgsExpressionFunction::Parameter( QStringLiteral( "include_layer_names" ), true, false )
                                      << QgsExpressionFunction::Parameter( QStringLiteral( "layer_name_separator" ), true, QStringLiteral( ": " ) ), QStringLiteral( "Layout" ) )
       , mLayout( c )
@@ -139,38 +139,57 @@ class GetLayoutMapLayerCredits : public QgsScopedExpressionFunction
         return QVariant();
 
       const QString id = values.value( 0 ).toString();
+      const bool includeLayerNames = values.value( 1 ).toBool();
+      const QString layerNameSeparator = values.value( 2 ).toString();
 
-      if ( QgsLayoutItemMap *map = qobject_cast< QgsLayoutItemMap * >( mLayout->itemById( id ) ) )
+      QList< QgsLayoutItemMap * > maps;
+      mLayout->layoutItems( maps );
+
+      // collect all the layers in matching maps first
+      QList< const QgsMapLayer * > layers;
+      bool foundMap = false;
+      for ( QgsLayoutItemMap *map : std::as_const( maps ) )
       {
+        if ( !id.isEmpty() && map->id() != id )
+          continue;
+
+        foundMap = true;
+
         const QgsExpressionContext c = map->createExpressionContext();
         const QVariantList mapLayers = c.variable( QStringLiteral( "map_layers" ) ).toList();
 
-        const bool includeLayerNames = values.value( 1 ).toBool();
-        const QString layerNameSeparator = values.value( 2 ).toString();
 
-        QVariantList res;
         for ( const QVariant &value : mapLayers )
         {
           if ( const QgsMapLayer *layer = qobject_cast< const QgsMapLayer * >( value.value< QObject * >() ) )
           {
-            const QStringList credits = !layer->metadata().rights().isEmpty() ? layer->metadata().rights() : QStringList() << layer->attribution();
-            for ( const QString &credit : credits )
-            {
-              if ( credit.trimmed().isEmpty() )
-                continue;
-
-              const QString creditString = includeLayerNames ? layer->name() + layerNameSeparator + credit
-                                           : credit;
-
-              if ( !res.contains( creditString ) )
-                res << creditString;
-            }
+            if ( !layers.contains( layer ) )
+              layers << layer;
           }
         }
+      }
+      if ( !foundMap )
+        return QVariant();
 
-        return res;
+      QVariantList res;
+      res.reserve( layers.size() );
+      for ( const QgsMapLayer *layer : std::as_const( layers ) )
+      {
+        const QStringList credits = !layer->metadata().rights().isEmpty() ? layer->metadata().rights() : QStringList() << layer->attribution();
+        for ( const QString &credit : credits )
+        {
+          if ( credit.trimmed().isEmpty() )
+            continue;
+
+          const QString creditString = includeLayerNames ? layer->name() + layerNameSeparator + credit
+                                       : credit;
+
+          if ( !res.contains( creditString ) )
+            res << creditString;
+        }
       }
-      return QVariant();
+
+      return res;
     }
 
     QgsScopedExpressionFunction *clone() const override

diff --git a/tests/src/core/testqgslayoutitem.cpp b/tests/src/core/testqgslayoutitem.cpp
@@ -1454,13 +1454,19 @@ void TestQgsLayoutItem::mapCreditsFunction()
   QVariant r = e.evaluate( &c );
   QVERIFY( !r.isValid() );
 
+  e = QgsExpression( QStringLiteral( "array_to_string( map_credits() )" ) );
+  r = e.evaluate( &c );
+  QVERIFY( !r.isValid() );
+
   QgsLayoutItemMap *map = new QgsLayoutItemMap( &l );
   map->setCrs( QgsCoordinateReferenceSystem( QStringLiteral( "EPSG:4326" ) ) );
   map->attemptSetSceneRect( QRectF( 30, 60, 200, 100 ) );
   map->setExtent( extent );
   l.addLayoutItem( map );
   map->setId( QStringLiteral( "Map_id" ) );
 
+  e = QgsExpression( QStringLiteral( "array_to_string( map_credits( 'Map_id' ) )" ) );
+
   c = l.createExpressionContext();
   e.prepare( &c );
   r = e.evaluate( &c );
@@ -1506,6 +1512,11 @@ void TestQgsLayoutItem::mapCreditsFunction()
   QgsExpression e4( QStringLiteral( "array_to_string( map_credits( 'Map_2', include_layer_names:=true ) )" ) );
   e4.prepare( &c );
   QCOMPARE( e4.evaluate( &c ).toString(), QStringLiteral( "A: CC BY SA" ) );
+
+  // credits from all maps
+  QgsExpression e5( QStringLiteral( "array_to_string( map_credits(include_layer_names:=true ) )" ) );
+  e5.prepare( &c );
+  QCOMPARE( e5.evaluate( &c ).toString(), QStringLiteral( "A: CC BY SA,B: CC NC,C: CC BY SA" ) );
 }
 
 void TestQgsLayoutItem::rotation()