Make features valid on setAttribute and setGeometry

Implements https://github.com/qgis/qgis3.0_api/issues/75

src/core/qgsfeature.cpp

@@ -142,12 +142,14 @@ void QgsFeature::setAttributes( const QgsAttributes &attrs )
 
   d.detach();
   d->attributes = attrs;
+  d->valid = true;
 }
 
 void QgsFeature::setGeometry( const QgsGeometry &geometry )
 {
   d.detach();
   d->geometry = geometry;
+  d->valid = true;
 }
 
 void QgsFeature::clearGeometry()
@@ -220,6 +222,7 @@ bool QgsFeature::setAttribute( int idx, const QVariant &value )
 
   d.detach();
   d->attributes[idx] = value;
+  d->valid = true;
   return true;
 }
 
@@ -237,6 +240,7 @@ bool QgsFeature::setAttribute( const QString &name, const QVariant &value )
 
   d.detach();
   d->attributes[fieldIdx] = value;
+  d->valid = true;
   return true;
 }
 

src/core/qgsfeature.h

@@ -196,6 +196,7 @@ class CORE_EXPORT QgsFeature
     QgsAttributes attributes() const;
 
     /** Sets the feature's attributes.
+     * The feature will be valid after.
      * @param attrs attribute list
      * @see setAttribute
      * @see attributes
@@ -203,6 +204,7 @@ class CORE_EXPORT QgsFeature
     void setAttributes( const QgsAttributes &attrs );
 
     /** Set an attribute's value by field index.
+     * The feature will be valid if it was successful.
      * @param field the index of the field to set
      * @param attr the value of the attribute
      * @return false, if the field index does not exist
@@ -251,7 +253,7 @@ class CORE_EXPORT QgsFeature
      */
     QgsGeometry geometry() const;
 
-    /** Set the feature's geometry.
+    /** Set the feature's geometry. The feature will be valid after.
      * @param geometry new feature geometry
      * @see geometry()
      * @see clearGeometry()
@@ -282,6 +284,7 @@ class CORE_EXPORT QgsFeature
 
     /** Insert a value into attribute. Returns false if attribute name could not be converted to index.
      *  Field map must be associated using @link setFields @endlink before this method can be used.
+     *  The feature will be valid if it was successful
      *  @param name The name of the field to set
      *  @param value The value to set
      *  @return false if attribute name could not be converted to index (C++ only)

tests/src/python/test_qgsfeature.py

@@ -46,6 +46,27 @@ class TestQgsFeature(unittest.TestCase):
         myMessage = '\nExpected: %s\nGot: %s' % ("True", myValidValue)
         assert myValidValue, myMessage
 
+    def test_Validity(self):
+        f = QgsFeature()
+        self.assertFalse(f.isValid())
+        f.setGeometry(QgsGeometry())
+        self.assertTrue(f.isValid())
+        f.setValid(False)
+        self.assertFalse(f.isValid())
+        fields = QgsFields()
+        field1 = QgsField('my_field')
+        fields.append(field1)
+        field2 = QgsField('my_field2')
+        fields.append(field2)
+        f.setFields(fields)
+        f.setAttribute(0, 0)
+        self.assertTrue(f.isValid())
+        f.setValid(False)
+        self.assertFalse(f.isValid())
+
+        f.setValid(False)
+        self.assertFalse(f.isValid())
+
     def test_Attributes(self):
         myPath = os.path.join(unitTestDataPath(), 'lines.shp')
         myLayer = QgsVectorLayer(myPath, 'Lines', 'ogr')