Implement sinkProperties for QgsProcessingFeatureBasedAlgorithm subcl…

…asses
qgis · Apr 7, 2020 · b2ca789 · b2ca789
1 parent 2d8da25
commit b2ca789
Show file tree

Hide file tree

Showing 3 changed files with 41 additions and 0 deletions.
diff --git a/python/core/auto_generated/processing/qgsprocessingalgorithm.sip.in b/python/core/auto_generated/processing/qgsprocessingalgorithm.sip.in
@@ -1191,6 +1191,11 @@ Read the source from ``parameters`` and ``context`` and set it
 .. versionadded:: 3.4
 %End
 
+     virtual QgsProcessingAlgorithm::VectorProperties sinkProperties( const QString &sink,
+        const QVariantMap &parameters,
+        QgsProcessingContext &context,
+        const QMap< QString, QgsProcessingAlgorithm::VectorProperties > &sourceProperties ) const;
+
 };
 
 

diff --git a/src/core/processing/qgsprocessingalgorithm.cpp b/src/core/processing/qgsprocessingalgorithm.cpp
@@ -1031,3 +1031,34 @@ void QgsProcessingFeatureBasedAlgorithm::prepareSource( const QVariantMap &param
   }
 }
 
+
+QgsProcessingAlgorithm::VectorProperties QgsProcessingFeatureBasedAlgorithm::sinkProperties( const QString &sink, const QVariantMap &parameters, QgsProcessingContext &context, const QMap<QString, QgsProcessingAlgorithm::VectorProperties> &sourceProperties ) const
+{
+  QgsProcessingAlgorithm::VectorProperties result;
+  if ( sink == QStringLiteral( "OUTPUT" ) )
+  {
+    if ( sourceProperties.value( QStringLiteral( "INPUT" ) ).availability == QgsProcessingAlgorithm::Available )
+    {
+      const VectorProperties inputProps = sourceProperties.value( QStringLiteral( "INPUT" ) );
+      result.fields = outputFields( inputProps.fields );
+      result.crs = outputCrs( inputProps.crs );
+      result.wkbType = outputWkbType( inputProps.wkbType );
+      result.availability = Available;
+      return result;
+    }
+    else
+    {
+      std::unique_ptr< QgsProcessingFeatureSource > source( parameterAsSource( parameters, QStringLiteral( "INPUT" ), context ) );
+      if ( source )
+      {
+        result.fields = outputFields( source->fields() );
+        result.crs = outputCrs( source->sourceCrs() );
+        result.wkbType = outputWkbType( source->wkbType() );
+        result.availability = Available;
+        return result;
+      }
+    }
+  }
+  return result;
+}
+
diff --git a/src/core/processing/qgsprocessingalgorithm.h b/src/core/processing/qgsprocessingalgorithm.h
@@ -1199,6 +1199,11 @@ class CORE_EXPORT QgsProcessingFeatureBasedAlgorithm : public QgsProcessingAlgor
      */
     void prepareSource( const QVariantMap &parameters, QgsProcessingContext &context );
 
+    QgsProcessingAlgorithm::VectorProperties sinkProperties( const QString &sink,
+        const QVariantMap &parameters,
+        QgsProcessingContext &context,
+        const QMap< QString, QgsProcessingAlgorithm::VectorProperties > &sourceProperties ) const override;
+
   private:
 
     std::unique_ptr< QgsProcessingFeatureSource > mSource;