[Dim] add to_dict and from_dict functions to cast from/to a dictionary

id06workflow/core/experiment/__init__.py

@@ -483,3 +483,38 @@ class Dim(object):
 
     def __str__(self):
         return " ".join((str(self.kind), str(self.name), 'size:', str(self.size)))
+
+    def to_dict(self):
+        """translate the current Dim to a dictionary"""
+        return {
+            'name': self.name,
+            'kind': self.kind,
+            'size': self.size,
+            'relative_prev_val': self.relative_prev_val,
+        }
+
+    @staticmethod
+    def from_dict(_dict):
+        """
+
+        :param dict _dict: dict defining the dimension. Should contains the
+                           following keys: name, kind, size, relative_prev_val
+                           unique values are not stored into it because it
+                           depends on the metadata and should be obtain from a
+                           fit / set_dims
+        :return: Dim corresponding to the dict given
+        :rtype: :class:`Dim`
+        """
+        assert type(_dict) is dict
+        missing_keys = []
+        for _key in ('name', 'kind', 'size', 'relative_prev_val'):
+            if _key not in _dict:
+                missing_keys.append(missing_keys)
+        if len(missing_keys) > 0:
+            raise ValueError('There is some missing keys (%s), unable to create'
+                             'a valid Dim')
+        else:
+            return Dim(name=_dict['name'],
+                       kind=_dict['kind'],
+                       size=_dict['size'],
+                       relative_prev_val=_dict['relative_prev_val'])