add native set layer metadata algorithm

src/analysis/processing/qgsmetadataalgorithms.cpp

@@ -89,4 +89,78 @@ QVariantMap QgsCopyLayerMetadataAlgorithm::processAlgorithm( const QVariantMap &
   return results;
 }
 
+
+
+QString QgsApplyLayerMetadataAlgorithm::name() const
+{
+  return QStringLiteral( "setlayermetadata" );
+}
+
+QString QgsApplyLayerMetadataAlgorithm::displayName() const
+{
+  return QObject::tr( "Set layer metadata" );
+}
+
+QStringList QgsApplyLayerMetadataAlgorithm::tags() const
+{
+  return QObject::tr( "change,layer,metadata,qmd" ).split( ',' );
+}
+
+QString QgsApplyLayerMetadataAlgorithm::group() const
+{
+  return QObject::tr( "Layer tools" );
+}
+
+QString QgsApplyLayerMetadataAlgorithm::groupId() const
+{
+  return QStringLiteral( "layertools" );
+}
+
+QString QgsApplyLayerMetadataAlgorithm::shortHelpString() const
+{
+  return QObject::tr( "Applies the metadata to a layer. The metadata must be defined as QMD file." );
+}
+
+QgsApplyLayerMetadataAlgorithm *QgsApplyLayerMetadataAlgorithm::createInstance() const
+{
+  return new QgsApplyLayerMetadataAlgorithm();
+}
+
+void QgsApplyLayerMetadataAlgorithm::initAlgorithm( const QVariantMap & )
+{
+  addParameter( new QgsProcessingParameterMapLayer( QStringLiteral( "INPUT" ), QObject::tr( "Layer" ) ) );
+  addParameter( new QgsProcessingParameterFile( QStringLiteral( "METADATA" ), QObject::tr( "Metadata file" ), Qgis::ProcessingFileParameterBehavior::File, QStringLiteral( "qmd" ) ) );
+  addOutput( new QgsProcessingOutputMapLayer( QStringLiteral( "OUTPUT" ), QObject::tr( "Updated" ) ) );
+}
+
+bool QgsApplyLayerMetadataAlgorithm::prepareAlgorithm( const QVariantMap &parameters, QgsProcessingContext &context, QgsProcessingFeedback * )
+{
+  QgsMapLayer *layer = parameterAsLayer( parameters, QStringLiteral( "INPUT" ), context );
+  const QString metadata = parameterAsFile( parameters, QStringLiteral( "METADATA" ), context );
+
+  if ( !layer )
+    throw QgsProcessingException( QObject::tr( "Invalid input layer" ) );
+
+  mLayerId = layer->id();
+
+  bool ok = false;
+  const QString msg = layer->loadNamedMetadata( metadata, ok );
+  if ( !ok )
+  {
+    throw QgsProcessingException( QObject::tr( "Failed to apply metadata. Error: %1" ).arg( msg ) );
+  }
+
+  return true;
+}
+
+QVariantMap QgsApplyLayerMetadataAlgorithm::processAlgorithm( const QVariantMap &parameters, QgsProcessingContext &context, QgsProcessingFeedback * )
+{
+  Q_UNUSED( parameters );
+  Q_UNUSED( context );
+
+  QVariantMap results;
+  results.insert( QStringLiteral( "OUTPUT" ), mLayerId );
+  return results;
+}
+
 ///@endcond

src/analysis/processing/qgsmetadataalgorithms.h

@@ -52,6 +52,33 @@ class QgsCopyLayerMetadataAlgorithm : public QgsProcessingAlgorithm
     QString mLayerId;
 };
 
+/**
+ * Native apply layer metadata algorithm.
+ */
+class QgsApplyLayerMetadataAlgorithm : public QgsProcessingAlgorithm
+{
+  public:
+    QgsApplyLayerMetadataAlgorithm() = default;
+    QString name() const override;
+    QString displayName() const override;
+    QStringList tags() const override;
+    QString group() const override;
+    QString groupId() const override;
+    QString shortHelpString() const override;
+    void initAlgorithm( const QVariantMap &configuration = QVariantMap() ) override;
+    QgsApplyLayerMetadataAlgorithm *createInstance() const override SIP_FACTORY;
+
+  protected:
+
+    bool prepareAlgorithm( const QVariantMap &parameters, QgsProcessingContext &context, QgsProcessingFeedback *feedback ) override;
+    QVariantMap processAlgorithm( const QVariantMap &parameters,
+                                  QgsProcessingContext &context, QgsProcessingFeedback * ) override;
+
+  private:
+
+    QString mLayerId;
+};
+
 ///@endcond PRIVATE
 
 #endif // QGSMETADATAALGORITHMS_H

src/analysis/processing/qgsnativealgorithms.cpp

@@ -300,6 +300,7 @@ void QgsNativeAlgorithms::loadAlgorithms()
   addAlgorithm( new QgsAlignRastersAlgorithm() );
   addAlgorithm( new QgsAlignSingleRasterAlgorithm() );
   addAlgorithm( new QgsAngleToNearestAlgorithm() );
+  addAlgorithm( new QgsApplyLayerMetadataAlgorithm() );
   addAlgorithm( new QgsApplyLayerStyleAlgorithm() );
   addAlgorithm( new QgsArrayTranslatedFeaturesAlgorithm() );
   addAlgorithm( new QgsAspectAlgorithm() );

tests/src/analysis/testqgsprocessingalgspt2.cpp

@@ -106,6 +106,7 @@ class TestQgsProcessingAlgsPt2: public QgsTest
     void generateElevationProfileImage();
 
     void copyMetadata();
+    void applyMetadata();
 
   private:
 
@@ -2028,6 +2029,34 @@ void TestQgsProcessingAlgsPt2::copyMetadata()
   QCOMPARE( targetMetadata.abstract(), QStringLiteral( "Abstract" ) );
 }
 
+void TestQgsProcessingAlgsPt2::applyMetadata()
+{
+  std::unique_ptr< QgsVectorLayer > layer = std::make_unique< QgsVectorLayer >( QStringLiteral( "Point?crs=epsg:4326&field=pk:int&field=col1:string" ), QStringLiteral( "input" ), QStringLiteral( "memory" ) );
+  QVERIFY( layer->isValid() );
+
+  std::unique_ptr< QgsProcessingAlgorithm > alg( QgsApplication::processingRegistry()->createAlgorithmById( QStringLiteral( "native:setlayermetadata" ) ) );
+  QVERIFY( alg != nullptr );
+
+  const QString dataDir( TEST_DATA_DIR ); //defined in CmakeLists.txt
+  const QString metadataFileName = dataDir + "/simple_metadata.qmd";
+
+  QVariantMap parameters;
+  parameters.insert( QStringLiteral( "INPUT" ), QVariant::fromValue( layer.get() ) );
+  parameters.insert( QStringLiteral( "METADATA" ), metadataFileName );
+
+  bool ok = false;
+  std::unique_ptr< QgsProcessingContext > context = std::make_unique< QgsProcessingContext >();
+  QgsProcessingFeedback feedback;
+  QVariantMap results;
+  results = alg->run( parameters, *context, &feedback, &ok );
+  QVERIFY( ok );
+
+  QCOMPARE( results.value( QStringLiteral( "OUTPUT" ) ), layer->id() );
+
+  QgsLayerMetadata targetMetadata = layer->metadata();
+  QCOMPARE( targetMetadata.title(), QStringLiteral( "Title" ) );
+  QCOMPARE( targetMetadata.abstract(), QStringLiteral( "Abstract" ) );
+}
 
 QGSTEST_MAIN( TestQgsProcessingAlgsPt2 )
 #include "testqgsprocessingalgspt2.moc"

tests/testdata/simple_metadata.qmd

@@ -0,0 +1,44 @@
+<!DOCTYPE qgis PUBLIC 'http://mrcc.com/qgis.dtd' 'SYSTEM'>
+<qgis version="3.40.0-Bratislava">
+  <identifier></identifier>
+  <parentidentifier></parentidentifier>
+  <language></language>
+  <type></type>
+  <title>Title</title>
+  <abstract>Abstract</abstract>
+  <contact>
+    <name></name>
+    <organization></organization>
+    <position></position>
+    <voice></voice>
+    <fax></fax>
+    <email></email>
+    <role></role>
+  </contact>
+  <links/>
+  <dates/>
+  <fees></fees>
+  <encoding></encoding>
+  <crs>
+    <spatialrefsys nativeFormat="Wkt">
+      <wkt></wkt>
+      <proj4></proj4>
+      <srsid>0</srsid>
+      <srid>0</srid>
+      <authid></authid>
+      <description></description>
+      <projectionacronym></projectionacronym>
+      <ellipsoidacronym></ellipsoidacronym>
+      <geographicflag>false</geographicflag>
+    </spatialrefsys>
+  </crs>
+  <extent>
+    <spatial miny="179769313486231570814527423731704356798070567525844996598917476803157260780028538760589558632766878171540458953514382464234321326889464182768467546703537516986049910576551282076245490090389328944075868508455133942304583236903222948165808559332123348274797826204144723168738177180919299881250404026184124858368" maxz="0" crs="" maxy="-179769313486231570814527423731704356798070567525844996598917476803157260780028538760589558632766878171540458953514382464234321326889464182768467546703537516986049910576551282076245490090389328944075868508455133942304583236903222948165808559332123348274797826204144723168738177180919299881250404026184124858368" maxx="-179769313486231570814527423731704356798070567525844996598917476803157260780028538760589558632766878171540458953514382464234321326889464182768467546703537516986049910576551282076245490090389328944075868508455133942304583236903222948165808559332123348274797826204144723168738177180919299881250404026184124858368" minx="179769313486231570814527423731704356798070567525844996598917476803157260780028538760589558632766878171540458953514382464234321326889464182768467546703537516986049910576551282076245490090389328944075868508455133942304583236903222948165808559332123348274797826204144723168738177180919299881250404026184124858368" minz="0" dimensions="2"/>
+    <temporal>
+      <period>
+        <start></start>
+        <end></end>
+      </period>
+    </temporal>
+  </extent>
+</qgis>