add category in QgsLayerMetadata using keywords

python/core/metadata/qgslayermetadata.sip

@@ -492,7 +492,7 @@ class QgsLayerMetadata
  CRS which is actually used to display and manipulate the layer within QGIS.
  This may be the case when a layer has an incorrect CRS within its metadata
  and a user has manually overridden the layer's CRS within QGIS.
-.. seealso:: setCrs()
+.. seealso:: crs()
 %End
 
     KeywordMap keywords() const;
@@ -535,6 +535,15 @@ class QgsLayerMetadata
 .. seealso:: setKeywords()
 %End
 
+    bool removeKeywords( const QString &vocabulary );
+%Docstring
+ Remove a vocabulary from the list.
+
+.. seealso:: setKeywords()
+.. seealso:: addKeywords()
+ :rtype: bool
+%End
+
     QStringList keywordVocabularies() const;
 %Docstring
  Returns a list of keyword vocabularies contained in the metadata.
@@ -559,6 +568,23 @@ class QgsLayerMetadata
  :rtype: list of str
 %End
 
+    QStringList categories() const;
+%Docstring
+ Returns categories of the resource.
+ Categories are stored using a special vocabulary 'gmd:topicCategory' in keywords.
+
+.. seealso:: keywords()
+ :rtype: list of str
+%End
+
+    void setCategories( const QStringList &categories );
+%Docstring
+ Sets categories of the resource.
+ Categories are stored using a special vocabulary 'gmd:topicCategory' in keywords.
+
+.. seealso:: keywords()
+%End
+
     QgsLayerMetadata::ContactList contacts() const;
 %Docstring
  Returns a list of contact persons or entities associated with the resource.

resources/qgis-resource-metadata.xml

@@ -6,6 +6,9 @@
     <type>dataset</type>
     <title>roads</title>
     <abstract>my roads</abstract>
+    <keywords vocabulary="gmd:topicCategory">
+        <keyword>natural</keyword>
+    </keywords>
     <keywords vocabulary="GEMET">
         <keyword>kw1</keyword>
         <keyword>kw2</keyword>

src/core/metadata/qgslayermetadata.cpp

@@ -158,6 +158,11 @@ void QgsLayerMetadata::addKeywords( const QString &vocabulary, const QStringList
   mKeywords.insert( vocabulary, keywords );
 }
 
+bool QgsLayerMetadata::removeKeywords( const QString &vocabulary )
+{
+  return mKeywords.remove( vocabulary );
+}
+
 QStringList QgsLayerMetadata::keywordVocabularies() const
 {
   return mKeywords.keys();
@@ -168,6 +173,23 @@ QStringList QgsLayerMetadata::keywords( const QString &vocabulary ) const
   return mKeywords.value( vocabulary );
 }
 
+QStringList QgsLayerMetadata::categories() const
+{
+  if ( mKeywords.contains( "gmd:topicCategory" ) )
+  {
+    return mKeywords.value( "gmd:topicCategory" );
+  }
+  else
+  {
+    return QStringList();
+  }
+}
+
+void QgsLayerMetadata::setCategories( const QStringList &category )
+{
+  mKeywords.insert( "gmd:topicCategory", category );
+}
+
 QList<QgsLayerMetadata::Contact> QgsLayerMetadata::contacts() const
 {
   return mContacts;

src/core/metadata/qgslayermetadata.h

@@ -545,7 +545,7 @@ class CORE_EXPORT QgsLayerMetadata
      * CRS which is actually used to display and manipulate the layer within QGIS.
      * This may be the case when a layer has an incorrect CRS within its metadata
      * and a user has manually overridden the layer's CRS within QGIS.
-     * \see setCrs()
+     * \see crs()
      */
     void setCrs( const QgsCoordinateReferenceSystem &crs );
 
@@ -588,6 +588,14 @@ class CORE_EXPORT QgsLayerMetadata
      */
     void addKeywords( const QString &vocabulary, const QStringList &keywords );
 
+    /**
+     * Remove a vocabulary from the list.
+     *
+     * \see setKeywords()
+     * \see addKeywords()
+     */
+    bool removeKeywords( const QString &vocabulary );
+
     /**
      * Returns a list of keyword vocabularies contained in the metadata.
      *
@@ -610,6 +618,22 @@ class CORE_EXPORT QgsLayerMetadata
      */
     QStringList keywords( const QString &vocabulary ) const;
 
+    /**
+     * Returns categories of the resource.
+     * Categories are stored using a special vocabulary 'gmd:topicCategory' in keywords.
+     *
+     * \see keywords()
+     */
+    QStringList categories() const;
+
+    /**
+     * Sets categories of the resource.
+     * Categories are stored using a special vocabulary 'gmd:topicCategory' in keywords.
+     *
+     * \see keywords()
+     */
+    void setCategories( const QStringList &categories );
+
     /**
      * Returns a list of contact persons or entities associated with the resource.
      * \see setContacts()

tests/src/python/test_qgslayermetadata.py

@@ -48,6 +48,9 @@ class TestQgsLayerMetadata(unittest.TestCase):
         m.setTitle('title')
         self.assertEqual(m.title(), 'title')
 
+        m.setCategories(['category'])
+        self.assertEqual(m.categories(), ['category'])
+
         m.setAbstract('abstract')
         self.assertEqual(m.abstract(), 'abstract')
 
@@ -102,6 +105,11 @@ class TestQgsLayerMetadata(unittest.TestCase):
     def testKeywords(self):
         m = QgsLayerMetadata()
 
+        m.setKeywords({'gmd:topicCategory': ['natural']})
+        self.assertEqual(m.keywords(), {'gmd:topicCategory': ['natural']})
+        self.assertEqual(m.categories(), ['natural'])
+        self.assertTrue(m.removeKeywords('gmd:topicCategory'))
+
         m.setKeywords({'vocab a': ['keyword a', 'other a'],
                        'vocab b': ['keyword b', 'other b']})
         self.assertEqual(m.keywords(), {'vocab a': ['keyword a', 'other a'],