Better handling of hyperdata modification

gargantext/models/nodes.py

@@ -10,6 +10,9 @@ from .users import User
 __all__ = ['Node', 'NodeNode', 'CorpusNode', 'DocumentNode']
 
 
+_UNDEFINED = object()
+
+
 class NodeType(TypeDecorator):
     """Define a new type of column to describe a Node's type.
     Internally, this column type is implemented as an SQL integer.
@@ -102,14 +105,21 @@ class Node(ValidatorMixin, Base):
         Base.__init__(self, **kwargs)
 
     def __getitem__(self, key):
-        """Allow direct access to hyperdata via the bracket operator.
-        """
+        """Allow direct access to hyperdata via the bracket operator."""
         return self.hyperdata[key]
 
     def __setitem__(self, key, value):
-        """Allow direct access to hyperdata via the bracket operator.
-        """
-        self.hyperdata[key] = value
+        """Allow direct access to hyperdata via the bracket operator."""
+        old_value = self.hyperdata.get(key, _UNDEFINED)
+        if old_value != value:
+            self.hyperdata[key] = value
+            flag_modified(self, 'hyperdata')
+
+    def __delitem(self, key):
+        """Allow direct access to hyperdata via the bracket operator."""
+        if key in self.hyperdata:
+            del self.hyperdata[key]
+            flag_modified(self, 'hyperdata')
 
     def __repr__(self):
         return '<{0.__class__.__name__}(id={0.id}, typename={0.typename!r}, ' \