Make fields() available in QgsVectorLayerFeatureSource

Author: m-kuhn

python/core/qgsvectorlayerfeatureiterator.sip

@@ -17,6 +17,7 @@ class QgsVectorLayerFeatureSource : QgsAbstractFeatureSource
     ~QgsVectorLayerFeatureSource();
 
     virtual QgsFeatureIterator getFeatures( const QgsFeatureRequest &request = QgsFeatureRequest() );
+    QgsFields fields();
 };
 
 class QgsVectorLayerFeatureIterator : QgsAbstractFeatureIterator

src/core/qgsvectorlayerfeatureiterator.cpp

@@ -93,6 +93,11 @@ QgsFeatureIterator QgsVectorLayerFeatureSource::getFeatures( const QgsFeatureReq
   return QgsFeatureIterator( new QgsVectorLayerFeatureIterator( this, false, request ) );
 }
 
+QgsFields QgsVectorLayerFeatureSource::fields()
+{
+  return mFields;
+}
+
 
 QgsVectorLayerFeatureIterator::QgsVectorLayerFeatureIterator( QgsVectorLayerFeatureSource *source, bool ownSource, const QgsFeatureRequest &request )
   : QgsAbstractFeatureIteratorFromSource<QgsVectorLayerFeatureSource>( source, ownSource, request )

src/core/qgsvectorlayerfeatureiterator.h

@@ -53,6 +53,14 @@ class CORE_EXPORT QgsVectorLayerFeatureSource : public QgsAbstractFeatureSource
 
     friend class QgsVectorLayerFeatureIterator;
 
+    /**
+     * Returns the fields that will be available for features that are retrieved from
+     * this source.
+     *
+     * \since QGIS 3.0
+     */
+    QgsFields fields();
+
   protected:
 
     QgsAbstractFeatureSource *mProviderFeatureSource = nullptr;