Add __table_handler__ to ModelSQL

issue7581
review48531002

address.py

@@ -11,7 +11,6 @@ from trytond.model import (
     ModelView, ModelSQL, MatchMixin, DeactivableMixin, fields,
     sequence_ordered)
 from trytond.pyson import Eval, If
-from trytond import backend
 from trytond.pool import Pool
 from trytond.transaction import Transaction
 from trytond.cache import Cache
@@ -57,13 +56,13 @@ class Address(DeactivableMixin, sequence_ordered(), ModelSQL, ModelView):
 
     @classmethod
     def __register__(cls, module_name):
-        TableHandler = backend.get('TableHandler')
         cursor = Transaction().connection.cursor()
-        table = TableHandler(cls, module_name)
         sql_table = cls.__table__()
 
         super(Address, cls).__register__(module_name)
 
+        table = cls.__table_handler__(module_name)
+
         # Migration from 2.4: drop required on sequence
         table.not_null_action('sequence', action='remove')
 

category.py

@@ -3,7 +3,6 @@
 from sql.conditionals import Coalesce
 from sql.operators import Equal
 
-from trytond import backend
 from trytond.model import (
     ModelView, ModelSQL, DeactivableMixin, fields, Exclude, tree)
 from trytond.pyson import Eval
@@ -42,10 +41,9 @@ class Category(DeactivableMixin, tree(separator=' / '), ModelSQL, ModelView):
 
     @classmethod
     def __register__(cls, module_name):
-        TableHandler = backend.get('TableHandler')
-        table_h = TableHandler(cls, module_name)
-
         super(Category, cls).__register__(module_name)
 
+        table_h = cls.__table_handler__(module_name)
+
         # Migration from 4.6: replace unique by exclude
         table_h.drop_constraint('name_parent_uniq')

contact_mechanism.py

@@ -9,7 +9,6 @@ except ImportError:
 from trytond.model import (
     ModelView, ModelSQL, DeactivableMixin, fields, sequence_ordered)
 from trytond.pyson import Eval
-from trytond import backend
 
 __all__ = ['ContactMechanism']
 
@@ -104,11 +103,10 @@ class ContactMechanism(
 
     @classmethod
     def __register__(cls, module_name):
-        TableHandler = backend.get('TableHandler')
-        table = TableHandler(cls, module_name)
-
         super(ContactMechanism, cls).__register__(module_name)
 
+        table = cls.__table_handler__(module_name)
+
         # Migration from 2.4: drop required on sequence
         table.not_null_action('sequence', action='remove')
 

party.py

@@ -87,11 +87,9 @@ class Party(DeactivableMixin, ModelSQL, ModelView, MultiValueMixin):
 
     @classmethod
     def __register__(cls, module_name):
-        TableHandler = backend.get('TableHandler')
-
         super(Party, cls).__register__(module_name)
 
-        table_h = TableHandler(cls, module_name)
+        table_h = cls.__table_handler__(module_name)
 
         # Migration from 3.8
         table_h.not_null_action('name', 'remove')
@@ -275,7 +273,7 @@ class PartyLang(ModelSQL, ValueMixin):
         super(PartyLang, cls).__register__(module_name)
 
         if not exist:
-            party_h = TableHandler(Party, module_name)
+            party_h = Party.__table_handler__(module_name)
             if party_h.column_exist('lang'):
                 query = table.insert(
                     [table.party, table.lang],
@@ -330,13 +328,12 @@ class PartyIdentifier(sequence_ordered(), ModelSQL, ModelView):
     def __register__(cls, module_name):
         pool = Pool()
         Party = pool.get('party.party')
-        TableHandler = backend.get('TableHandler')
         cursor = Transaction().connection.cursor()
         party = Party.__table__()
 
         super(PartyIdentifier, cls).__register__(module_name)
 
-        party_h = TableHandler(Party, module_name)
+        party_h = Party.__table_handler__(module_name)
         if (party_h.column_exist('vat_number')
                 and party_h.column_exist('vat_country')):
             identifiers = []