[FIX] api: improve decorator `returns` to handle special cases, like method `search`

Add the possibility in the decorator to specify the `upgrade` and `downgrade`
functions that convert values between APIs.  Both function have the same API:

    upgrade(self, value, *args, **kwargs)
    downgrade(self, value, *args, **kwargs)

The arguments ``self``, ``*args`` and ``**kwargs`` are the ones passed to the
method, following its new-API signature.

Fixes #4944, #7830.

openerp/addons/base/tests/test_api.py

@@ -66,6 +66,15 @@ class TestAPI(common.TransactionCase):
         self.assertIsRecordset(partners2, 'res.partner')
         self.assertEqual(list(partners1), list(partners2))
 
+    @mute_logger('openerp.models')
+    def test_04_query_count(self):
+        """ Test the search method with count=True. """
+        count1 = self.registry('res.partner').search(self.cr, self.uid, [], count=True)
+        count2 = self.env['res.partner'].search([], count=True)
+        self.assertIsInstance(count1, (int, long))
+        self.assertIsInstance(count2, (int, long))
+        self.assertEqual(count1, count2)
+
     @mute_logger('openerp.models')
     def test_05_immutable(self):
         """ Check that a recordset remains the same, even after updates. """

openerp/api.py

@@ -209,13 +209,19 @@ def depends(*args):
     return lambda method: decorate(method, '_depends', args)
 
 
-def returns(model, downgrade=None):
+def returns(model, downgrade=None, upgrade=None):
     """ Return a decorator for methods that return instances of ``model``.
 
         :param model: a model name, or ``'self'`` for the current model
 
-        :param downgrade: a function ``downgrade(value)`` to convert the
-            record-style ``value`` to a traditional-style output
+        :param downgrade: a function ``downgrade(self, value, *args, **kwargs)``
+            to convert the record-style ``value`` to a traditional-style output
+
+        :param upgrade: a function ``upgrade(self, value, *args, **kwargs)``
+            to convert the traditional-style ``value`` to a record-style output
+
+        The arguments ``self``, ``*args`` and ``**kwargs`` are the ones passed
+        to the method in the record-style.
 
         The decorator adapts the method output to the api style: ``id``, ``ids`` or
         ``False`` for the traditional style, and recordset for the record style::
@@ -237,7 +243,7 @@ def returns(model, downgrade=None):
         a decorated existing method will be decorated with the same
         ``@returns(model)``.
     """
-    return lambda method: decorate(method, '_returns', (model, downgrade))
+    return lambda method: decorate(method, '_returns', (model, downgrade, upgrade))
 
 
 def make_wrapper(decorator, method, old_api, new_api):
@@ -260,30 +266,39 @@ def make_wrapper(decorator, method, old_api, new_api):
 
 
 def get_downgrade(method):
-    """ Return a function `downgrade(value)` that adapts ``value`` from
-        record-style to traditional-style, following the convention of ``method``.
+    """ Return a function `downgrade(self, value, *args, **kwargs)` that adapts
+        ``value`` from record-style to traditional-style, following the
+        convention of ``method``.
     """
     spec = getattr(method, '_returns', None)
     if spec:
-        model, downgrade = spec
-        return downgrade or (lambda value: value.ids)
+        _, downgrade, _ = spec
+        if downgrade and len(getargspec(downgrade).args) > 1:
+            return downgrade
+        elif downgrade:
+            return lambda self, *args, **kwargs: downgrade(args[0])
+        else:
+            return lambda self, *args, **kwargs: args[0].ids
     else:
-        return lambda value: value
+        return lambda self, *args, **kwargs: args[0]
 
 
 def get_upgrade(method):
-    """ Return a function `upgrade(self, value)` that adapts ``value`` from
-        traditional-style to record-style, following the convention of ``method``.
+    """ Return a function `upgrade(self, value, *args, **kwargs)` that adapts
+        ``value`` from traditional-style to record-style, following the
+        convention of ``method``.
     """
     spec = getattr(method, '_returns', None)
     if spec:
-        model, downgrade = spec
-        if model == 'self':
-            return lambda self, value: self.browse(value)
+        model, _, upgrade = spec
+        if upgrade:
+            return upgrade
+        elif model == 'self':
+            return lambda self, *args, **kwargs: self.browse(args[0])
         else:
-            return lambda self, value: self.env[model].browse(value)
+            return lambda self, *args, **kwargs: self.env[model].browse(args[0])
     else:
-        return lambda self, value: value
+        return lambda self, *args, **kwargs: args[0]
 
 
 def get_aggregate(method):
@@ -293,7 +308,7 @@ def get_aggregate(method):
     spec = getattr(method, '_returns', None)
     if spec:
         # value is a list of instances, concatenate them
-        model, downgrade = spec
+        model, _, _ = spec
         if model == 'self':
             return lambda self, value: sum(value, self.browse())
         else:
@@ -343,7 +358,7 @@ def model(method):
         context, args, kwargs = split(args, kwargs)
         recs = self.browse(cr, uid, [], context)
         result = method(recs, *args, **kwargs)
-        return downgrade(result)
+        return downgrade(recs, result, *args, **kwargs)
 
     return make_wrapper(model, method, old_api, method)
 
@@ -370,7 +385,7 @@ def multi(method):
         context, args, kwargs = split(args, kwargs)
         recs = self.browse(cr, uid, ids, context)
         result = method(recs, *args, **kwargs)
-        return downgrade(result)
+        return downgrade(recs, result, *args, **kwargs)
 
     return make_wrapper(multi, method, old_api, method)
 
@@ -410,7 +425,7 @@ def one(method):
         context, args, kwargs = split(args, kwargs)
         recs = self.browse(cr, uid, ids, context)
         result = new_api(recs, *args, **kwargs)
-        return downgrade(result)
+        return downgrade(recs, result, *args, **kwargs)
 
     def new_api(self, *args, **kwargs):
         result = [method(rec, *args, **kwargs) for rec in self]
@@ -433,7 +448,7 @@ def cr(method):
     def new_api(self, *args, **kwargs):
         cr, uid, context = self.env.args
         result = method(self._model, cr, *args, **kwargs)
-        return upgrade(self, result)
+        return upgrade(self, result, *args, **kwargs)
 
     return make_wrapper(cr, method, method, new_api)
 
@@ -444,9 +459,9 @@ def cr_context(method):
 
     def new_api(self, *args, **kwargs):
         cr, uid, context = self.env.args
-        kwargs['context'] = context
-        result = method(self._model, cr, *args, **kwargs)
-        return upgrade(self, result)
+        old_kwargs = dict(kwargs, context=context)
+        result = method(self._model, cr, *args, **old_kwargs)
+        return upgrade(self, result, *args, **kwargs)
 
     return make_wrapper(cr_context, method, method, new_api)
 
@@ -458,7 +473,7 @@ def cr_uid(method):
     def new_api(self, *args, **kwargs):
         cr, uid, context = self.env.args
         result = method(self._model, cr, uid, *args, **kwargs)
-        return upgrade(self, result)
+        return upgrade(self, result, *args, **kwargs)
 
     return make_wrapper(cr_uid, method, method, new_api)
 
@@ -477,9 +492,9 @@ def cr_uid_context(method):
 
     def new_api(self, *args, **kwargs):
         cr, uid, context = self.env.args
-        kwargs['context'] = context
-        result = method(self._model, cr, uid, *args, **kwargs)
-        return upgrade(self, result)
+        old_kwargs = dict(kwargs, context=context)
+        result = method(self._model, cr, uid, *args, **old_kwargs)
+        return upgrade(self, result, *args, **kwargs)
 
     return make_wrapper(cr_uid_context, method, method, new_api)
 
@@ -494,7 +509,7 @@ def cr_uid_id(method):
     def new_api(self, *args, **kwargs):
         cr, uid, context = self.env.args
         result = [method(self._model, cr, uid, id, *args, **kwargs) for id in self.ids]
-        return upgrade(self, result)
+        return upgrade(self, result, *args, **kwargs)
 
     return make_wrapper(cr_uid_id, method, method, new_api)
 
@@ -518,9 +533,9 @@ def cr_uid_id_context(method):
 
     def new_api(self, *args, **kwargs):
         cr, uid, context = self.env.args
-        kwargs['context'] = context
-        result = [method(self._model, cr, uid, id, *args, **kwargs) for id in self.ids]
-        return upgrade(self, result)
+        old_kwargs = dict(kwargs, context=context)
+        result = [method(self._model, cr, uid, id, *args, **old_kwargs) for id in self.ids]
+        return upgrade(self, result, *args, **kwargs)
 
     return make_wrapper(cr_uid_id_context, method, method, new_api)
 
@@ -535,7 +550,7 @@ def cr_uid_ids(method):
     def new_api(self, *args, **kwargs):
         cr, uid, context = self.env.args
         result = method(self._model, cr, uid, self.ids, *args, **kwargs)
-        return upgrade(self, result)
+        return upgrade(self, result, *args, **kwargs)
 
     return make_wrapper(cr_uid_ids, method, method, new_api)
 
@@ -561,9 +576,9 @@ def cr_uid_ids_context(method):
 
     def new_api(self, *args, **kwargs):
         cr, uid, context = self.env.args
-        kwargs['context'] = context
-        result = method(self._model, cr, uid, self.ids, *args, **kwargs)
-        return upgrade(self, result)
+        old_kwargs = dict(kwargs, context=context)
+        result = method(self._model, cr, uid, self.ids, *args, **old_kwargs)
+        return upgrade(self, result, *args, **kwargs)
 
     return make_wrapper(cr_uid_ids_context, method, method, new_api)
 

openerp/models.py

@@ -1625,7 +1625,9 @@ class BaseModel(object):
             return len(res)
         return res
 
-    @api.returns('self')
+    @api.returns('self',
+        upgrade=lambda self, value, args, offset=0, limit=None, order=None, count=False: value if count else self.browse(value),
+        downgrade=lambda self, value, args, offset=0, limit=None, order=None, count=False: value if count else value.ids)
     def search(self, cr, user, args, offset=0, limit=None, order=None, context=None, count=False):
         """ search(args[, offset=0][, limit=None][, order=None][, count=False])