[postgres] Automatically populate layer metadata

Not much is available to automatically populate, but we can set the abstract to match the table comment, the crs, and datatype.
qgis · Mar 14, 2018 · 7dd5caf · 7dd5caf
1 parent f55347f
commit 7dd5caf
Show file tree

Hide file tree

Showing 2 changed files with 17 additions and 0 deletions.
diff --git a/src/providers/postgres/qgspostgresprovider.cpp b/src/providers/postgres/qgspostgresprovider.cpp
@@ -278,6 +278,9 @@ QgsPostgresProvider::QgsPostgresProvider( QString const &uri )
   {
     disconnectDb();
   }
+
+  mLayerMetadata.setType( QStringLiteral( "dataset" ) );
+  mLayerMetadata.setCrs( crs() );
 }
 
 QgsPostgresProvider::~QgsPostgresProvider()
@@ -653,6 +656,11 @@ QgsWkbTypes::Type QgsPostgresProvider::wkbType() const
   return mRequestedGeomType != QgsWkbTypes::Unknown ? mRequestedGeomType : mDetectedGeomType;
 }
 
+QgsLayerMetadata QgsPostgresProvider::layerMetadata() const
+{
+  return mLayerMetadata;
+}
+
 QgsField QgsPostgresProvider::field( int index ) const
 {
   if ( index < 0 || index >= mAttributeFields.count() )
@@ -713,7 +721,10 @@ bool QgsPostgresProvider::loadFields()
     sql = QStringLiteral( "SELECT description FROM pg_description WHERE objoid=%1 AND objsubid=0" ).arg( tableoid );
     tresult = connectionRO()->PQexec( sql );
     if ( tresult.PQntuples() > 0 )
+    {
       mDataComment = tresult.PQgetvalue( 0, 0 );
+      mLayerMetadata.setAbstract( mDataComment );
+    }
   }
 
   // Populate the field vector for this layer. The field vector contains
@@ -1254,6 +1265,9 @@ bool QgsPostgresProvider::hasSufficientPermsAndCapabilities()
   // supports circular geometries
   mEnabledCapabilities |= QgsVectorDataProvider::CircularGeometries;
 
+  // supports layer metadata
+  mEnabledCapabilities |= QgsVectorDataProvider::ReadLayerMetadata;
+
   if ( ( mEnabledCapabilities & QgsVectorDataProvider::ChangeGeometries ) &&
        ( mEnabledCapabilities & QgsVectorDataProvider::ChangeAttributeValues ) &&
        mSpatialColType != SctTopoGeometry )

diff --git a/src/providers/postgres/qgspostgresprovider.h b/src/providers/postgres/qgspostgresprovider.h
@@ -98,6 +98,7 @@ class QgsPostgresProvider : public QgsVectorDataProvider
     QgsCoordinateReferenceSystem crs() const override;
     QgsFeatureIterator getFeatures( const QgsFeatureRequest &request ) const override;
     QgsWkbTypes::Type wkbType() const override;
+    QgsLayerMetadata layerMetadata() const override;
 
     /**
      * Return the number of layers for the current data source
@@ -447,6 +448,8 @@ class QgsPostgresProvider : public QgsVectorDataProvider
 
     bool mCheckPrimaryKeyUnicity = true;
 
+    QgsLayerMetadata mLayerMetadata;
+
     std::unique_ptr< QgsPostgresListener > mListener;
 };