From 084b8af6c1db6f8cf0465ffeb550c43473d65ef5 Mon Sep 17 00:00:00 2001
From: Yann <yann.weber@openedition.org>
Date: Fri, 24 Jul 2015 17:21:50 +0200
Subject: [PATCH] MigrationHandler enhancement (now records Model's hash for
 each changes). Better beaviour of Model.create_component if MigrationHandler
 raises

---
 EditorialModel/components.py             |  5 ++++-
 EditorialModel/migrationhandler/dummy.py |  6 +++++-
 EditorialModel/model.py                  | 13 ++++++++++++-
 3 files changed, 21 insertions(+), 3 deletions(-)

diff --git a/EditorialModel/components.py b/EditorialModel/components.py
index 0d4445a..560deac 100644
--- a/EditorialModel/components.py
+++ b/EditorialModel/components.py
@@ -61,10 +61,13 @@ class EmComponent(object):
 
     ## @brief Reimplementation for calling the migration handler to register the change
     def __setattr__(self, attr_name, value):
-        if '_inited' in self.__dict__:
+        inited = '_inited' in self.__dict__
+        if inited:
             # if fails raise MigrationHandlerChangeError
             self.model.migration_handler.register_change(self.uid, {attr_name: getattr(self, attr_name) }, {attr_name: value} )
         super(EmComponent, self).__setattr__(attr_name, value)
+        if inited:
+            self.model.migration_handler.register_model_state(hash(self.model))
 
     ## Check the type of attribute named var_name
     # @param var_name str : the attribute name
diff --git a/EditorialModel/migrationhandler/dummy.py b/EditorialModel/migrationhandler/dummy.py
index 57fdbf8..60cfd87 100644
--- a/EditorialModel/migrationhandler/dummy.py
+++ b/EditorialModel/migrationhandler/dummy.py
@@ -36,4 +36,8 @@ class DummyMigrationHandler(object):
                     print(str_chg)
             print("##############\n")
         pass
-        
+    
+    def register_model_state(self, state_hash):
+        if self.debug:
+            print("New EditorialModel sate registered : '%s'"%state_hash)
+
diff --git a/EditorialModel/model.py b/EditorialModel/model.py
index 271006a..59525da 100644
--- a/EditorialModel/model.py
+++ b/EditorialModel/model.py
@@ -147,7 +147,16 @@ class Model(object):
         em_component.init_ended()
 
         #register the creation in migration handler
-        self.migration_handler.register_change(em_component.uid, None, em_component.attr_dump)
+        try:
+            self.migration_handler.register_change(em_component.uid, None, em_component.attr_dump)
+        except MigrationHandlerChangeError as e:
+            #Revert the creation
+            self.components(em_component.__class__).remove(em_component)
+            del self._components['uids'][em_component.uid]
+            print(self._components)
+            raise e
+
+        self.migration_handler.register_model_state(hash(self))
 
         return em_component
 
@@ -166,6 +175,8 @@ class Model(object):
         if em_component.delete_check():
             self._components[self.name_from_emclass(em_component.__class__)].remove(em_component)
             del self._components['uids'][uid]
+        #Register the new EM state
+        self.migration_handler.register_model_state(hash(self))
         return True
 
     ## Changes the current backend