Merge branch 'migration_handler':

Add the possibility to change the migartion handler of a Model
It will send changes one by one to the new migartion handler
so it can re-create the Editorial Model

EditorialModel/backend/dummy_backend.py

@@ -0,0 +1,17 @@
+# -*- coding: utf-8 -*-
+
+## @package EditorialModel.backend.dummy_backend
+# @brief Gives an empty backend
+#
+# Allows an editorial model to use an empty backend
+# Mostly for migration and test purpose
+
+## Manages a Json file based backend structure
+class EmBackendDummy(object):
+
+    def load(self):
+        data = {}
+        return data
+
+    def save(self):
+        return True

EditorialModel/model.py

@@ -4,6 +4,7 @@
 # Manage instance of an editorial model
 
 from EditorialModel.migrationhandler.dummy import DummyMigrationHandler
+from EditorialModel.backend.dummy_backend import EmBackendDummy
 from EditorialModel.classes import EmClass
 from EditorialModel.fieldgroups import EmFieldGroup
 from EditorialModel.fields import EmField
@@ -15,7 +16,7 @@ import hashlib
 ## Manages the Editorial Model
 class Model(object):
 
-    components_class = [EmClass, EmField, EmFieldGroup, EmType]
+    components_class = [EmClass, EmType, EmFieldGroup, EmField]
 
     ## Constructor
     #
@@ -129,7 +130,7 @@ class Model(object):
     # @param datas dict : the options needed by the component creation
     # @throw ValueError if datas['rank'] is not valid (too big or too small, not an integer nor 'last' or 'first' )
     # @todo Handle a raise from the migration handler
-    def create_component(self, component_type, datas):
+    def create_component(self, component_type, datas, uid=None):
 
         em_obj = self.emclass_from_name(component_type)
 
@@ -138,13 +139,13 @@ class Model(object):
             rank = datas['rank']
             del datas['rank']
 
-        datas['uid'] = self.new_uid()
+        datas['uid'] = uid if uid else self.new_uid()
         em_component = em_obj(self, **datas)
 
-        em_component.rank = em_component.get_max_rank() + 1 #Inserting last by default
+        em_component.rank = em_component.get_max_rank() + 1 #  Inserting last by default
 
         self._components['uids'][em_component.uid] = em_component
-        self._components[self.name_from_emclass(em_component.__class__)].append(em_component)
+        self._components[component_type].append(em_component)
 
         if rank != 'last':
             em_component.set_rank(1 if rank == 'first' else rank)
@@ -193,3 +194,39 @@ class Model(object):
     ## Returns a list of all the EmClass objects of the model
     def classes(self):
         return list(self._components[self.name_from_emclass(EmClass)])
+
+    ## Use a new migration handler, re-apply all the ME to this handler
+    #
+    # @param new_mh MigrationHandler: A migration_handler object
+    # @warning : if a relational-attribute field (with 'rel_field_id') comes before it's relational field (with 'rel_to_type_id'), this will blow up
+    def migrate_handler(self, new_mh):
+        new_me = Model(EmBackendDummy(), new_mh)
+        relations = {'fields_list': [], 'superiors_list': []}
+
+        # re-create component one by one, in components_class[] order
+        for cls in self.components_class:
+            for component in self.components(cls):
+                component_type = self.name_from_emclass(cls)
+                component_dump = component.attr_dump
+                del component_dump['model'], component_dump['_inited']
+                # Save relations between component to apply them later
+                for relation in relations.keys():
+                    if relation in component_dump and component_dump[relation]:
+                        relations[relation].append((component.uid, component_dump[relation]))
+                        del component_dump[relation]
+                new_me.create_component(component_type, component_dump, component.uid)
+
+        # apply selected field  to types
+        for fields_list in relations['fields_list']:
+            uid, fields = fields_list
+            for field_id in fields:
+                new_me.component(uid).select_field(new_me.component(field_id))
+
+        # add superiors to types
+        # TODO: debug, this add a superior to all types !
+        for superiors_list in relations['superiors_list']:
+            uid, sup_list = superiors_list
+            for nature, superior_uid in sup_list.items():
+                new_me.component(uid).add_superior(new_me.component(superior_uid), nature)
+
+        self.migration_handler = new_mh

EditorialModel/test/me.json

@@ -12,7 +12,7 @@
     "component":"EmField", "name":"titre", "string":"{\"fre\":\"Titre\"}", "help_text":"{}", "rank":"1", "date_update":"", "date_create":"", "fieldtype":"varchar", "fieldgroup_id":"3", "rel_to_type_id":"", "rel_field_id":"", "optional":0, "internal":"", "icon":"0"
   },
   "5" : {
-    "component":"EmType", "name":"article", "string":"{\"fre\":\"Article\"}", "help_text":"{}", "rank":"1", "date_update":"", "date_create":"", "class_id":"1", "icon":"0", "sortcolumn":"rank", "fields_list":[7]
+    "component":"EmType", "name":"article", "string":"{\"fre\":\"Article\"}", "help_text":"{}", "rank":"1", "date_update":"", "date_create":"", "class_id":"1", "icon":"0", "sortcolumn":"rank", "fields_list":[7], "superiors_list":{"parent":14}
   },
   "6" : {
     "component":"EmType", "name":"personne", "string":"{\"fre\":\"Personne\"}", "help_text":"{}", "rank":"1", "date_update":"", "date_create":"", "class_id":"2", "icon":"0", "sortcolumn":"rank", "fields_list":[10]
@@ -30,16 +30,16 @@
     "component":"EmField", "name":"prenom", "string":"{\"fre\":\"Preom\"}", "help_text":"{}", "rank":"2", "date_update":"", "date_create":"", "fieldtype":"varchar", "fieldgroup_id":"8", "rel_to_type_id":"", "rel_field_id":"", "optional":1, "internal":"", "icon":"0"
   },
   "11" : {
-    "component":"EmField", "name":"auteur", "string":"{\"fre\":\"Auteur\"}", "help_text":"{}", "rank":"3", "date_update":"", "date_create":"", "fieldtype":"varchar", "fieldgroup_id":"17", "rel_to_type_id":"6", "rel_field_id":"", "optional":1, "internal":"", "icon":"0"
+    "component":"EmField", "name":"auteur", "string":"{\"fre\":\"Auteur\"}", "help_text":"{}", "rank":"1", "date_update":"", "date_create":"", "fieldtype":"varchar", "fieldgroup_id":"17", "rel_to_type_id":"6", "rel_field_id":"", "optional":1, "internal":"", "icon":"0"
   },
   "12" : {
-    "component":"EmField", "name":"adresse", "string":"{\"fre\":\"Adresse\"}", "help_text":"{}", "rank":"4", "date_update":"", "date_create":"", "fieldtype":"varchar", "fieldgroup_id":"17", "rel_to_type_id":"", "rel_field_id":"11", "optional":0, "internal":"", "icon":"0"
+    "component":"EmField", "name":"adresse", "string":"{\"fre\":\"Adresse\"}", "help_text":"{}", "rank":"2", "date_update":"", "date_create":"", "fieldtype":"varchar", "fieldgroup_id":"17", "rel_to_type_id":"", "rel_field_id":"11", "optional":0, "internal":"", "icon":"0"
   },
   "13" : {
     "component":"EmClass", "name":"publication", "string":"{\"fre\":\"Publication\"}", "help_text":"{}", "rank":"2", "date_update":"", "date_create":"", "classtype":"entity", "icon":"0", "sortcolumn":"rank"
   },
   "14" : {
-    "component":"EmType", "name":"rubrique", "string":"{\"fre\":\"Rubrique\"}", "help_text":"{}", "rank":"1", "date_update":"", "date_create":"", "class_id":"13", "icon":"0", "sortcolumn":"rank", "subordinates_list":{"parent":[5,14]}
+    "component":"EmType", "name":"rubrique", "string":"{\"fre\":\"Rubrique\"}", "help_text":"{}", "rank":"1", "date_update":"", "date_create":"", "class_id":"13", "icon":"0", "sortcolumn":"rank", "superiors_list":{"parent":14}
   },
   "15" : {
     "component":"EmFieldGroup", "name":"info", "string":"{\"fre\":\"Info\"}", "help_text":"{}", "rank":"1", "date_update":"", "date_create":"", "class_id":"13"

EditorialModel/types.py

@@ -25,7 +25,7 @@ class EmType(EmComponent):
     ## Instanciate a new EmType
     # @todo define and check types for icon and sortcolumn
     # @todo better check self.subordinates
-    def __init__(self, model, uid, name, class_id, fields_list = [], subordinates_list = {}, icon = '0', sortcolumn = 'rank', string = None, help_text = None, date_update = None, date_create = None, rank = None):
+    def __init__(self, model, uid, name, class_id, fields_list = [], superiors_list = {}, icon = '0', sortcolumn = 'rank', string = None, help_text = None, date_update = None, date_create = None, rank = None):
         self.class_id = class_id
         self.check_type('class_id', int)
         self.fields_list = fields_list
@@ -34,14 +34,13 @@ class EmType(EmComponent):
             if not isinstance(l_uid, int):
                 raise AttributeError("Excepted fields_list to be a list of integers, but found a +"+str(type(l_uid))+" in it")
 
-        self.subordinates_list = subordinates_list
-        self.check_type('subordinates_list', dict)
-        for nature, uids in self.subordinates_list.items():
+        self.superiors_list = superiors_list
+        self.check_type('superiors_list', dict)
+        for nature, sup_uid in self.superiors_list.items():
             if nature not in [EmNature.PARENT, EmNature.TRANSLATION, EmNature.IDENTITY]:
                 raise AttributeError("Nature '%s' of subordinates is not allowed !" % nature)
-            for uid in uids:
-                if not isinstance(uid, int):
-                    raise AttributeError("Excepted subordinates of nature '%s' to be a list int !" % nature)
+            if not isinstance(sup_uid, int):
+                raise AttributeError("Excepted subordinates of nature '%s' to be an int !" % nature)
 
         self.icon = icon
         self.sortcolumn = sortcolumn
@@ -79,7 +78,7 @@ class EmType(EmComponent):
     # @todo Check if the type is not linked by any EmClass
     # @todo Check if there is no other ''non-deletion'' conditions
     def delete_check(self):
-        if sum(self.subordinates_list) > 0:
+        if len(self.subordinates()) > 0:
             return False
         #Delete all relation with superiors
         for nature, sups in self.superiors().items():
@@ -110,52 +109,61 @@ class EmType(EmComponent):
     # Indicates that an optional field is used
     #
     # @param field EmField: The optional field to select
-    # @return True if success False if failed
     #
     # @throw TypeError if field is not an EmField instance
     # @throw ValueError if field is not optional or is not associated with this type
-    # @see EmType::_opt_field_act()
+    # @throw MigrationHandlerChangeError if migration handler is not happy with the change
+    # @see EmType::_change_field_list()
     def select_field(self, field):
         if field.uid in self.fields_list:
             return True
-        return self._change_field_list(field, True)
+        self._change_field_list(field, True)
 
     ## Unselect_field (Function)
     #
     # Indicates that an optional field will not be used
     #
     # @param field EmField: The optional field to unselect
-    # @return True if success False if fails
     #
     # @throw TypeError if field is not an EmField instance
     # @throw ValueError if field is not optional or is not associated with this type
-    # @see EmType::_opt_field_act()
+    # @throw MigrationHandlerChangeError if migration handler is not happy with the change
+    # @see EmType::_change_field_list()
     def unselect_field(self, field):
         if field.uid not in self.fields_list:
             return True
-        return self._change_field_list(field, False)
+        self._change_field_list(field, False)
 
     ## @brief Select or unselect an optional field
     # @param field EmField: The EmField to select or unselect
     # @param select bool: If True select field, else unselect it
-    # @return True if success False if fails
     #
     # @throw TypeError if field is not an EmField instance
     # @throw ValueError if field is not optional or is not associated with this type
-    def _change_field_list(self, field, add=True):  # TODO voir si on conserve l'argument "select"
+    # @throw MigrationHandlerChangeError if migration handler is not happy with the change
+    def _change_field_list(self, field, select=True):
         if not isinstance(field, EmField):
             raise TypeError("Excepted <class EmField> as field argument. But got " + str(type(field)))
         if not field in self.em_class.fields():
-            raise ValueError("This field is not part of this type")
+            raise ValueError("This field " + str(field) + "is not part of the type " + str(self))
         if not field.optional:
             raise ValueError("This field is not optional")
 
-        if add:
-            self.fields_list.append(field.uid)
-        else:
-            self.fields_list.remove(field.uid)
-
-        return True
+        try:
+            if select:
+                self.fields_list.append(field.uid)
+                self.model.migration_handler.register_change(self.model, self.uid, None, {'fields_list': field.uid})
+            else:
+                self.fields_list.remove(field.uid)
+                self.model.migration_handler.register_change(self.model, self.uid, {'fields_list': field.uid}, None)
+        except MigrationHandlerChangeError as exception_object:
+            if select:
+                self.fields_list.remove(field.uid)
+            else:
+                self.fields_list.append(field.uid)
+            raise exception_object
+
+        self.model.migration_handler.register_model_state(self.model, hash(self.model))
 
     ## Get the list of associated hooks
     # @note Not conceptualized yet
@@ -186,22 +194,22 @@ class EmType(EmComponent):
     # EmType instance
     # @throw RuntimeError if a nature fetched from db is not valid
     def subordinates(self):
-        return { nature: [ self.model.component(tuid) for tuid in self.subordinates_list[nature] ] for nature in self.subordinates_list }
+        subordinates = {}
+        for em_type in self.model.components(EmType):
+            for nature, superior_uid in em_type.superiors_list.items():
+                if self.uid == superior_uid:
+                    if nature in subordinates:
+                        subordinates[nature].append(em_type)
+                    else:
+                        subordinates[nature] = [em_type]
+        return subordinates
 
     ## @brief Get the list of superiors by relation's nature
     # Get a list of EmType that are superiors of this type
     # @return Return a dict with relation nature as keys and an EmType as value
     # @throw RuntimeError if a nature has multiple superiors
     def superiors(self):
-        superiors = {}
-        for em_type in self.model.components(EmType):
-            for nature, sub_uids in em_type.subordinates_list.items():
-                if self.uid in sub_uids:
-                    if nature in superiors:
-                        raise RuntimeError("Multiple superiors found for relation of nature '%s' for EmType %d"%(nature, self.uid))
-                    else:
-                        superiors[nature] = em_type
-        return superiors
+        return { nature:self.model.component(superior_uid) for nature, superior_uid in self.superiors_list.items() }
 
     ## Add a superior in the type hierarchy
     # @param em_type EmType: An EmType instance
@@ -212,11 +220,6 @@ class EmType(EmComponent):
     # @throw ValueError when relation_nature isn't reconized or not allowed for this type
     # @throw ValueError when relation_nature don't allow to link this types together
     def add_superior(self, em_type, relation_nature):
-        if not isinstance(em_type, EmType) or not isinstance(relation_nature, str):
-            raise TypeError("Excepted <class EmType> and <class str> as em_type argument. But got : " + str(type(em_type)) + " " + str(type(relation_nature)))
-        if relation_nature not in EmClassType.natures(self.classtype['name']):
-            raise ValueError("Invalid nature for add_superior : '" + relation_nature + "'. Allowed relations for this type are " + str(EmClassType.natures(self.classtype['name'])))
-
         #Checking that this relation is allowed by the nature of the relation
         att = self.classtype['hierarchy'][relation_nature]['attach']
         if att == 'classtype':
@@ -225,65 +228,44 @@ class EmType(EmComponent):
         elif self.name != em_type.name:
             raise ValueError("Not allowed to put a different em_type as superior in a relation of nature '" + relation_nature + "'")
 
-        # TODO Réimplémenter
-        # conn = self.db_engine.connect()
-        # htable = self._table_hierarchy
-        # values = {'subordinate_id': self.uid, 'superior_id': em_type.uid, 'nature': relation_nature}
-        # req = htable.insert(values=values)
-        #
-        # try:
-        #     conn.execute(req)
-        # except sql.exc.IntegrityError:
-        #     ret = False
-        # else:
-        #     ret = True
-        # finally:
-        #     conn.close()
-        #
-        # return ret
+        self._change_superiors_list(em_type, relation_nature, True)
 
     ## Delete a superior in the type hierarchy
     # @param em_type EmType: An EmType instance
+    # @param relation_nature str: The name of the relation's nature
     # @throw TypeError when em_type isn't an EmType instance
+    # @throw ValueError when relation_nature isn't reconized or not allowed for this type
     def del_superior(self, em_type, relation_nature):
-        if not isinstance(em_type, EmType):
-            raise TypeError("Excepted <class EmType> as argument. But got : " + str(type(em_type)))
+        self._change_superiors_list(em_type, relation_nature, False)
+
+    ## Apply changes to the superiors_list
+    # @param em_type EmType: An EmType instance
+    # @param relation_nature str: The name of the relation's nature
+    # @param add bool: Add or delete relation
+    def _change_superiors_list(self, em_type, relation_nature, add=True):
+        # check instance of parameters
+        if not isinstance(em_type, EmType) or not isinstance(relation_nature, str):
+            raise TypeError("Excepted <class EmType> and <class str> as em_type argument. But got : " + str(type(em_type)) + " " + str(type(relation_nature)))
+        # check if relation_nature is valid for this type
         if relation_nature not in EmClassType.natures(self.classtype['name']):
             raise ValueError("Invalid nature for add_superior : '" + relation_nature + "'. Allowed relations for this type are " + str(EmClassType.natures(self.classtype['name'])))
 
-        # TODO Réimplémenter
-        # conn = self.db_engine.connect()
-        # htable = self._table_hierarchy
-        # req = htable.delete(htable.c.superior_id == em_type.uid and htable.c.nature == relation_nature)
-        # conn.execute(req)
-        # conn.close()
-
-    ## @brief Get the list of linked type
-    # Types are linked with special fields called relation_to_type fields
-    # @return a list of EmType
-    # @see EmFields
-    def linked_types(self):
-        return self._linked_types_db()  # TODO changer l'appel
-
-    ## @brief Return the list of all the types linked to this type, should they be superiors or subordinates
-    # @return A list of EmType objects
-    # def _linked_types_db(self):
-    #     conn = self.db_engine.connect()
-    #     htable = self._table_hierarchy
-    #     req = htable.select(htable.c.superior_id, htable.c.subordinate_id)
-    #     req = req.where(sql.or_(htable.c.subordinate_id == self.uid, htable.c.superior_id == self.uid))
-    #
-    #     res = conn.execute(req)
-    #     rows = res.fetchall()
-    #     conn.close()
-    #
-    #     rows = dict(zip(rows.keys(), rows))
-    #     result = []
-    #     for row in rows:
-    #         result.append(EmType(row['subordinate_id'] if row['superior_id'] == self.uid else row['superior_id']))
-    #
-    #     return result
-    
+        try:
+            if add:
+                self.superiors_list[relation_nature] = em_type.uid
+                self.model.migration_handler.register_change(self.model, self.uid, None, {'superiors_list': {relation_nature: em_type.uid}})
+            else:
+                del self.superiors_list[relation_nature]
+                self.model.migration_handler.register_change(self.model, self.uid, {'superiors_list': {relation_nature: em_type.uid}}, None)
+        except MigrationHandlerChangeError as exception_object:
+            if add:
+                del self.superiors_list[relation_nature]
+            else:
+                self.superiors_list[relation_nature] = em_type.uid
+            raise exception_object
+
+        self.model.migration_handler.register_model_state(self.model, hash(self.model))
+
     ## Checks if the EmType is valid
     # @throw EmComponentCheckError if check fails
     def check(self):
@@ -293,52 +275,50 @@ class EmType(EmComponent):
             raise EmComponentCheckError("class_id contains an uid that does not exists '%d'" % self.class_id)
         if not isinstance(em_class, EditorialModel.classes.EmClass):
             raise EmComponentCheckError("class_id contains an uid from a component that is not an EmClass but a %s" % str(type(emc_class)))
-        
-        for i,fuid in enumerate(self.fields_list):
-            field = self.model.component(fuid)
+
+        for i,f_uid in enumerate(self.fields_list):
+            field = self.model.component(f_uid)
             if not field:
-                raise EmComponentCheckError("The element %d of selected_field is a non existing uid '%d'"%(i, fuid))
+                raise EmComponentCheckError("The element %d of selected_field is a non existing uid '%d'"%(i, f_uid))
             if not isinstance(field, EmField):
                 raise EmComponentCheckError("The element %d of selected_field is not an EmField but a %s" % (i, str(type(field)) ))
             if not field.optional:
                 raise EmComponentCheckError("The element %d of selected_field is an EmField not optional"  % i )
             if field.fieldgroup_id not in [ fg.uid for fg in self.fieldgroups() ]:
                 raise EmComponentCheckErrro("The element %d of selected_field is an EmField that is part of an EmFieldGroup that is not associated with this EmType" % i)
-        for nature in self.subordinates_list:
-            for i, tuid in enumerate(self.subordinates_list[nature]):
-                em_type = self.model.component(tuid)
-                if not em_type:
-                    raise EmComponentCheckError("The element %d of subordinates contains a non existing uid '%d'" % (i, tuid))
-                if not isinstance(em_type, EmType):
-                    raise EmComponentCheckError("The element %d of subordinates contains a component that is not an EmType but a %s" % (i, str(type(em_type))))
-                if nature not in EmClassType.natures(self.em_class.classtype):
-                    raise EmComponentCheckError("The relation nature '%s' of the element %d of subordinates is not valid for this EmType classtype '%s'", (nature, i, self.classtype) )
-    
-                nat_spec = getattr(EmClassType, self.em_class.classtype)['hierarchy'][nature]
-    
-                if nat_spec['attach'] == 'classtype':
-                    if self.classtype != em_type.classtype:
-                        raise EmComponentCheckError("The element %d of subordinates is of '%s' classtype. But the current type is of '%s' classtype, and relation nature '%s' require two EmType of same classtype" % (i, em_type.classtype, self.classtype, nature) )
-                elif nat_spec['attach'] == 'type':
-                    if self.uid != em_type.uid:
-                        raise EmComponentCheckError("The element %d of subordinates is a different EmType. But the relation nature '%s' require the same EmType" % (i, nature))
+
+        for nature, sup_uid in self.superiors_list.items():
+            em_type = self.model.component(sup_uid)
+            if not em_type:
+                raise EmComponentCheckError("The superior is a non existing uid '%d'" % (sup_uid))
+            if not isinstance(em_type, EmType):
+                raise EmComponentCheckError("The superior is a component that is not an EmType but a %s" % (str(type(em_type))))
+            if nature not in EmClassType.natures(self.em_class.classtype):
+                raise EmComponentCheckError("The relation nature '%s' of the superior is not valid for this EmType classtype '%s'", (nature, self.classtype) )
+
+            nat_spec = getattr(EmClassType, self.em_class.classtype)['hierarchy'][nature]
+
+            if nat_spec['attach'] == 'classtype':
+                if self.classtype != em_type.classtype:
+                    raise EmComponentCheckError("The superior is of '%s' classtype. But the current type is of '%s' classtype, and relation nature '%s' require two EmType of same classtype" % (em_type.classtype, self.classtype, nature) )
+            elif nat_spec['attach'] == 'type':
+                if self.uid != em_type.uid:
+                    raise EmComponentCheckError("The superior is a different EmType. But the relation nature '%s' require the same EmType" % (nature))
+            else:
+                raise NotImplementedError("The nature['attach'] '%s' is not implemented in this check !" % nat_spec['attach'])
+
+            if 'max_depth' in nat_spec and nat_spec['max_depth'] > 0:
+                depth = 1
+                cur_type = em_type
+                while depth >= nat_spec['max_depth']:
+                    depth +=1
+                    if len(cur_type.subordinates()[nature]) == 0:
+                        break
                 else:
-                    raise NotImplementedError("The nature['attach'] '%s' is not implemented in this check !" % nat_spec['attach'])
-    
-                if 'max_depth' in nat_spec and nat_spec['max_depth'] > 0:
-                    depth = 1
-                    cur_type = em_type
-                    while depth >= nat_spec['max_depth']:
-                        depth +=1
-                        if len(cur_type.subordinates()[nature]) == 0:
-                            break
-                    else:
-                        raise EmComponentCheckError("The relation with the element %d of subordinates has a depth superior than the maximum depth ( %d ) allowed by the relation's nature ( '%s' )" %( i, nat_spec['max_depth'], nature) )
-        
+                    raise EmComponentCheckError("The relation with the element %d of subordinates has a depth superior than the maximum depth ( %d ) allowed by the relation's nature ( '%s' )" %( i, nat_spec['max_depth'], nature) )
+
         for nature in self.subordinates():
             nat_spec = getattr(EmClassType, self.em_class.classtype)['hierarchy'][nature]
             if 'max_child' in nat_spec and nat_spec['max_child'] > 0:
                 if len(self.subordinates()[nature]) > nat_spec['max_child']:
                     raise EmComponentCheckError("The EmType has more child than allowed in the relation's nature : %d > %d" (len(self.subordinates()[nature], nat_spec['max_child'])))
-        #pass
-