More features and refactoring

README.md

@@ -94,22 +94,25 @@ class BackendA(DSync):
 
 ## Update Remote system on Sync
 
-To update a remote system, you need to extend your DSync object to define your own `create`, `update` or `delete` method for each model. The DSync engine will automatically look for `create_<modelname>`, `update_<modelname>` or  `delete_<modelname>` depending on the status of the object.
-Each method need to accept 2 dict, `keys` and `params` and should return a DSyncModel object:
-- `keys` dict containing all identifier for this object
-- `params` dict containing all attributes for this object
+To update a remote system, you need to extend your DSyncModel class(es) to define your own `create`, `update` and/or `delete` methods for each model.
+A DSyncModel instance stores a reference to its parent DSync class in case you need to use it to look up other model instances from the DSync's cache.
 
 ```python
-class BackendA(DSync):
+class Device(DSyncModel):
     [...]
 
-    def create_device(self, keys, params):
+    @classmethod
+    def create(cls, dsync, ids, attrs):
         ## TODO add your own logic here to create the device on the remote system
-        item = self.default_create(object_type="device", keys=keys, params=params)
-        return item
+        return cls(**ids, **attrs)
 
-    def update_device(self, keys, params):
+    def update(self, attrs):
         ## TODO add your own logic here to update the device on the remote system
-        item = self.default_update(object_type="device", keys=keys, params=params)
-        return item
+        for attr, value in attrs.items():
+            setattr(self, attr, value)
+        return self
+
+    def delete(self):
+        ## TODO add your own logic here to delete the device on the remote system
+        return self
 ```