Merge pull request #3720 from sbrunner/WFS-provider-metadata

Add metadata for WFS provider in layer metadata informations

python/core/qgsvectordataprovider.sip

@@ -386,6 +386,12 @@ class QgsVectorDataProvider : QgsDataProvider
      */
     virtual QList<QgsRelation> discoverRelations( const QgsVectorLayer* self, const QList<QgsVectorLayer*>& layers ) const;
 
+    /**
+     * Get some metadata that will be display in the metadata tab of the layer properties.
+     * @return The provider metadata
+     */
+    virtual QMap<QString, QString> metadata() const;
+
   signals:
     /**
      * Signals an error in this provider

src/core/qgsvectordataprovider.h

@@ -390,7 +390,7 @@ class CORE_EXPORT QgsVectorDataProvider : public QgsDataProvider
      * Returns true if the provider is strict about the type of inserted features
      * (e.g. no multipolygon in a polygon layer)
      */
-    virtual bool doesStrictFeatureTypeCheck() const { return true;}
+    virtual bool doesStrictFeatureTypeCheck() const { return true; }
 
     //! Returns a list of available encodings
     static QStringList availableEncodings();
@@ -446,6 +446,12 @@ class CORE_EXPORT QgsVectorDataProvider : public QgsDataProvider
      */
     virtual QList<QgsRelation> discoverRelations( const QgsVectorLayer* self, const QList<QgsVectorLayer*>& layers ) const;
 
+    /**
+     * Get some metadata that will be display in the metadata tab of the layer properties.
+     * @return The provider metadata
+     */
+    virtual QMap<QString, QString> metadata() const { return QMap<QString, QString>(); };
+
   signals:
     /**
      * Signals an error in this provider

src/core/qgsvectorlayer.cpp

@@ -3889,6 +3889,20 @@ QString QgsVectorLayer::metadata() const
     myMetadata += QLatin1String( "<p>" );
     myMetadata += dataProvider()->description().replace( '\n', QLatin1String( "<br>" ) );
     myMetadata += QLatin1String( "</p>\n" );
+
+    QMap<QString, QString> dataProviderMetadata = mDataProvider->metadata();
+    if ( !dataProviderMetadata.isEmpty() )
+    {
+      myMetadata += "<p class=\"glossy\">" + tr( "Provider Metadata" ) + "</p>\n";
+      myMetadata +=  "<p><table><tr><th>" + tr( "Metadata name" ) + "</th><th>" + tr( "Metadata value" ) + "</th></tr>\n";
+      QMapIterator<QString, QString> i( dataProviderMetadata );
+      while ( i.hasNext() )
+      {
+        i.next();
+        myMetadata += "<tr><td>" + i.key() + ":</td><td>" + i.value() + "</td></tr>\n";
+      }
+      myMetadata += QLatin1String( "</table></p>\n" );
+    }
   }
 
   // data source

src/providers/wfs/qgswfsprovider.cpp

@@ -1100,6 +1100,16 @@ bool QgsWFSProvider::changeAttributeValues( const QgsChangedAttributesMap &attr_
   }
 }
 
+
+QMap<QString, QString> QgsWFSProvider::metadata()
+{
+  QMap<QString, QString> result;
+  result[tr( "Max Features" )] = mShared->mCaps.maxFeatures == 0 ? tr( "not provided" ) : QString( mShared->mCaps.maxFeatures );
+  result[tr( "Supports Paging" )] = mShared->mCaps.supportsPaging ? tr( "supported" ) : tr( "unsupported" );
+  result[tr( "Supports Joins" )] = mShared->mCaps.supportsJoins ? tr( "supported" ) : tr( "unsupported" );
+  return result;
+}
+
 bool QgsWFSProvider::describeFeatureType( QString& geometryAttribute, QgsFields& fields, QgsWkbTypes::Type& geomType )
 {
   fields.clear();

src/providers/wfs/qgswfsprovider.h

@@ -132,6 +132,12 @@ class QgsWFSProvider : public QgsVectorDataProvider
      */
     virtual bool changeAttributeValues( const QgsChangedAttributesMap &attr_map ) override;
 
+    /**
+     * Get some metadata description of the provider.
+     * @return The provider metadata
+     */
+    virtual QMap<QString, QString> metadata();
+
   public slots:
     /** Reloads the data from the source. Needs to be implemented by providers with data caches to
       synchronize with changes in the data source*/