diff --git a/EditorialModel/backend/json_backend.py b/EditorialModel/backend/json_backend.py
index 53f9a97..09fb155 100644
--- a/EditorialModel/backend/json_backend.py
+++ b/EditorialModel/backend/json_backend.py
@@ -9,17 +9,23 @@
 import json
 import datetime
 from Lodel.utils.mlstring import MlString
+import EditorialModel
 
 
 def date_cast(date):
     if len(date):
-        return datetime.datetime(date)
+        return datetime.datetime.strptime(date, '%c')
     else:
         return None
 
 
+## @brief dirty obsolote cast function
 def int_or_none(i):
-    if len(i):
+    if isinstance(i, int):
+        return i
+    elif i is None:
+        return None
+    elif len(i):
         return int(i)
     else:
         return None
@@ -47,27 +53,35 @@ class EmBackendJson(object):
     #
     # @param json_file str: path to the json_file used as data source
     def __init__(self, json_file):
-        with open(json_file) as json_data:
-            self.data = json.loads(json_data.read())
+        self.json_file = json_file
+        pass
+
+    @staticmethod
+    ## @brief Used by json.dumps to serialize date and datetime
+    def date_handler(obj):
+        return obj.strftime('%c') if isinstance(obj, datetime.datetime) or isinstance(obj, datetime.date) else None
+
 
     ## Loads the data in the data source json file
     #
     # @return list
     def load(self):
         data = {}
-        for index, component in self.data.items():
-            attributes = {}
-            for attr_name, attr_value in component.items():
-                if attr_name in EmBackendJson.cast_methods:
-                    attributes[attr_name] = EmBackendJson.cast_methods[attr_name](attr_value)
-                else:
-                    attributes[attr_name] = attr_value
-            data[int(index)] = attributes
+        with open(self.json_file) as json_data:
+            rdata = json.loads(json_data.read())
+            for index, component in rdata.items():
+                attributes = {}
+                for attr_name, attr_value in component.items():
+                    if attr_name in EmBackendJson.cast_methods:
+                        attributes[attr_name] = EmBackendJson.cast_methods[attr_name](attr_value)
+                    else:
+                        attributes[attr_name] = attr_value
+                data[int(index)] = attributes
         return data
 
     ## Saves the data in the data source json file
-    #
-    # @return bool
-    # @todo à implémenter
-    def save(self, em):
-        return True
+    # @param filename str : The filename to save the EM in (if None use self.json_file provided at init )
+    def save(self, em, filename = None):
+        with open(self.json_file if filename is None else filename, 'w') as fp:
+            fp.write(json.dumps({ component.uid : component.dumps() for component in em.components() }, default=self.date_handler))
+
diff --git a/EditorialModel/components.py b/EditorialModel/components.py
index 062aa10..67cc041 100644
--- a/EditorialModel/components.py
+++ b/EditorialModel/components.py
@@ -56,7 +56,7 @@ class EmComponent(object):
     ## @brief Return a dict with attributes name as key and attributes value as value
     # @note Used at creation and deletion to call the migration handler
     def attr_dump(self):
-        return {fname: fval for fname, fval in self.__dict__.items() if not (fname.startswith('__') or (fname == 'uid'))}
+        return {fname: fval for fname, fval in self.__dict__.items() if not (fname.startswith('_') or (fname == 'uid'))}
 
     @property
     ## @brief Provide a uniq name
@@ -71,6 +71,23 @@ class EmComponent(object):
         uname += '_'+self.name
         return uname
         
+    ## @brief dumps attr for serialization
+    def dumps(self):
+        #attr =  {fname: fval for fname, fval in self.__dict__.items() if not (fname.startswith('_'))}
+        attr = self.attr_dump
+        del(attr['model'])
+        for attr_f in attr:
+            if isinstance(attr[attr_f], EmComponent):
+                attr[attr_f] = attr[attr_f].uid
+            elif isinstance(attr[attr_f], MlString):
+                attr[attr_f] = attr[attr_f].__str__()
+        if isinstance(self, EditorialModel.fields.EmField):
+            attr['component'] = 'EmField'
+            attr['type'] = self.fieldtype
+        else:
+            attr['component'] = self.__class__.__name__
+        return attr
+
     ## @brief This function has to be called after the instanciation, checks, and init manipulations are done
     # @note Create a new attribute _inited that allow __setattr__ to know if it has or not to call the migration handler
     def init_ended(self):
diff --git a/EditorialModel/fields.py b/EditorialModel/fields.py
index 5729422..e83da5d 100644
--- a/EditorialModel/fields.py
+++ b/EditorialModel/fields.py
@@ -22,7 +22,7 @@ class EmField(EmComponent):
     ## Instanciate a new EmField
     # @todo define and test type for icon and fieldtype
     # @warning nullable == True by default
-    def __init__(self, model, uid, name, fieldgroup_id, optional=False, internal=False, rel_field_id=None, icon='0', string=None, help_text=None, date_update=None, date_create=None, rank=None, nullable = True, default = None, uniq = False, **kwargs):
+    def __init__(self, model, uid, name, fieldgroup_id, fieldtype, optional=False, internal=False, rel_field_id=None, icon='0', string=None, help_text=None, date_update=None, date_create=None, rank=None, nullable = True, default = None, uniq = False, **kwargs):
 
         if self.ftype == None:
             raise NotImplementedError("Trying to instanciate an EmField and not one of the fieldtypes child classes")
@@ -37,7 +37,9 @@ class EmField(EmComponent):
         self.check_type('rel_field_id', (int, type(None)))
         self.icon = icon
 
+
         #Field type elements
+        self.fieldtype = fieldtype
         self.nullable = nullable
         self.default = default
         self.uniq = uniq
diff --git a/EditorialModel/model.py b/EditorialModel/model.py
index f9153a2..59db940 100644
--- a/EditorialModel/model.py
+++ b/EditorialModel/model.py
@@ -77,6 +77,7 @@ class Model(object):
                 if not 'type' in kwargs:
                     raise AttributeError("Missing 'type' from EmField instanciation")
                 cls = EditorialModel.fields.EmField.get_field_class(kwargs['type'])
+                kwargs['fieldtype'] = kwargs['type']
                 del(kwargs['type'])
             else:
                 cls = self.emclass_from_name(cls_name)
@@ -103,13 +104,16 @@ class Model(object):
             component.init_ended()
 
     ## Saves data using the current backend
-    def save(self):
-        return self.backend.save(self)
+    # @param filename str | None : if None use the current backend file (provided at backend instanciation)
+    def save(self, filename = None):
+        return self.backend.save(self, filename)
 
     ## Given a EmComponent child class return a list of instances
     # @param cls EmComponent : A python class
     # @return a list of instances or False if the class is not an EmComponent child
-    def components(self, cls):
+    def components(self, cls=None):
+        if cls is None:
+            return [ self.component(uid) for uid in self._components['uids'] ]
         key_name = self.name_from_emclass(cls)
         return False if key_name is False else self._components[key_name]