Fix outdated example code, convert to python

(because c++ devs are l33t and don't need examples...)

python/core/qgsfeaturerequest.sip.in

@@ -31,19 +31,25 @@ For efficiency, it is also possible to tell provider that some data is not requi
 - SimplifyMethod for geometries to fetch
 
 The options may be chained, e.g.:
-QgsFeatureRequest().setFilterRect(QgsRectangle(0,0,1,1)).setFlags(QgsFeatureRequest.ExactIntersect)
+
+.. code-block:: python
+
+       QgsFeatureRequest().setFilterRect(QgsRectangle(0,0,1,1)).setFlags(QgsFeatureRequest.ExactIntersect)
 
 Examples:
-- fetch all features:
-QgsFeatureRequest()
-- fetch all features, only one attribute
-QgsFeatureRequest().setSubsetOfAttributes(QStringList("myfield"), provider->fieldMap())
-- fetch all features, without geometries
-QgsFeatureRequest().setFlags(QgsFeatureRequest.NoGeometry)
-- fetch only features from particular extent
-QgsFeatureRequest().setFilterRect(QgsRectangle(0,0,1,1))
-- fetch only one feature
-QgsFeatureRequest().setFilterFid(45)
+
+.. code-block:: python
+
+       # fetch all features:
+       QgsFeatureRequest()
+       # fetch all features, only one attribute
+       QgsFeatureRequest().setSubsetOfAttributes(['myfield'], layer.fields())
+       # fetch all features, without geometries
+       QgsFeatureRequest().setFlags(QgsFeatureRequest.NoGeometry)
+       # fetch only features from particular extent
+       QgsFeatureRequest().setFilterRect(QgsRectangle(0,0,1,1))
+       # fetch only one feature
+       QgsFeatureRequest().setFilterFid(45)
 %End
 
 %TypeHeaderCode

src/core/qgsfeaturerequest.h

@@ -49,20 +49,25 @@
  * - SimplifyMethod for geometries to fetch
  *
  * The options may be chained, e.g.:
- *   QgsFeatureRequest().setFilterRect(QgsRectangle(0,0,1,1)).setFlags(QgsFeatureRequest::ExactIntersect)
+ *
+ * \code{.py}
+ *   QgsFeatureRequest().setFilterRect(QgsRectangle(0,0,1,1)).setFlags(QgsFeatureRequest.ExactIntersect)
+ * \endcode
  *
  * Examples:
- * - fetch all features:
- *     QgsFeatureRequest()
- * - fetch all features, only one attribute
- *     QgsFeatureRequest().setSubsetOfAttributes(QStringList("myfield"), provider->fieldMap())
- * - fetch all features, without geometries
- *     QgsFeatureRequest().setFlags(QgsFeatureRequest::NoGeometry)
- * - fetch only features from particular extent
- *     QgsFeatureRequest().setFilterRect(QgsRectangle(0,0,1,1))
- * - fetch only one feature
- *     QgsFeatureRequest().setFilterFid(45)
  *
+ * \code{.py}
+ *   # fetch all features:
+ *   QgsFeatureRequest()
+ *   # fetch all features, only one attribute
+ *   QgsFeatureRequest().setSubsetOfAttributes(['myfield'], layer.fields())
+ *   # fetch all features, without geometries
+ *   QgsFeatureRequest().setFlags(QgsFeatureRequest.NoGeometry)
+ *   # fetch only features from particular extent
+ *   QgsFeatureRequest().setFilterRect(QgsRectangle(0,0,1,1))
+ *   # fetch only one feature
+ *   QgsFeatureRequest().setFilterFid(45)
+ * \endcode
  */
 class CORE_EXPORT QgsFeatureRequest
 {