[IMP] Cleanup and refactoring of exception handling

Unify and refactor exception handling in framework and addons.

The generic `except_osv` is now deprecated, and replaced by more specialized exception subtypes:
 - `UserError` (renamed from Warning, as it conflicts with the built-in `Warning`) raised when a non-technical error occurs during a business operation. It could be a missing information in the data provided by the user, or a misconfiguration.
 - `AccessError`: raised when any operation is denied because the user conducting it does not have the required access rights.
 - `AccessDenied`: raised when an operation that requires authenticated access is attempted via an unauthenticated request.
 - `MissingError`: raised when an operation is attempted on a record that does not exist.
 - `ValidationError`: raised when an operation violates a SQL or Python constraint.
 - All other exceptions are internal errors due to a system problem or bug, and raised untouched to the client-side, which should display a traceback.

All exceptions take a single message argument.

The `test_exceptions` module has been updated to showcase both new and old (deprecated) exceptions.

A great many old `except_osv` had a useless title with "Error!" or "Warning", those have been removed, as this is handled by the client-side widget that displays the messages.

This commit introduces a more consistent policy for logging errors and warnings:
 - All messages that do not require administrator attention should be logged at INFO level or lower. This includes all errors that are notified to the user in a friendly manner, even for access right problems or validation errors during business operations.
 - All messages that indicate a likely misconfiguration or malicious use by the users should be logged at WARNING level, as they typically require administrator attention.
 - All other unhandled internal errors cannot typically be handled by the user and should be logged at ERROR or higher level, as they require immediate administrator attention.

4 files changed, 13 insertions, 9 deletions

diff --git a/addons/gamification/models/badge.py b/addons/gamification/models/badge.py
index c078943ee0e..c21595a5d0d 100644
--- a/addons/gamification/models/badge.py
+++ b/addons/gamification/models/badge.py
@@ -26,6 +26,7 @@ from openerp.tools.translate import _
 
 from datetime import date
 import logging
+from openerp.exceptions import UserError
 
 _logger = logging.getLogger(__name__)
 
@@ -235,13 +236,13 @@ class gamification_badge(osv.Model):
         if status_code == self.CAN_GRANT:
             return True
         elif status_code == self.NOBODY_CAN_GRANT:
-            raise osv.except_osv(_('Warning!'), _('This badge can not be sent by users.'))
+            raise UserError(_('This badge can not be sent by users.'))
         elif status_code == self.USER_NOT_VIP:
-            raise osv.except_osv(_('Warning!'), _('You are not in the user allowed list.'))
+            raise UserError(_('You are not in the user allowed list.'))
         elif status_code == self.BADGE_REQUIRED:
-            raise osv.except_osv(_('Warning!'), _('You do not have the required badges.'))
+            raise UserError(_('You do not have the required badges.'))
         elif status_code == self.TOO_MANY:
-            raise osv.except_osv(_('Warning!'), _('You have already sent this badge too many time this month.'))
+            raise UserError(_('You have already sent this badge too many time this month.'))
         else:
             _logger.exception("Unknown badge status code: %d" % int(status_code))
         return False
diff --git a/addons/gamification/models/challenge.py b/addons/gamification/models/challenge.py
index a804d816a05..22f054eb7a9 100644
--- a/addons/gamification/models/challenge.py
+++ b/addons/gamification/models/challenge.py
@@ -28,6 +28,7 @@ from openerp.tools.translate import _
 from datetime import date, datetime, timedelta
 import calendar
 import logging
+from openerp.exceptions import UserError
 _logger = logging.getLogger(__name__)
 
 # display top 3 in ranking, could be db variable
@@ -248,7 +249,7 @@ class gamification_challenge(osv.Model):
         elif vals.get('state') == 'draft':
             # resetting progress
             if self.pool.get('gamification.goal').search(cr, uid, [('challenge_id', 'in', ids), ('state', '=', 'inprogress')], context=context):
-                raise osv.except_osv("Error", "You can not reset a challenge with unfinished goals.")
+                raise UserError(_("You can not reset a challenge with unfinished goals."))
 
         return write_res
 
@@ -553,7 +554,7 @@ class gamification_challenge(osv.Model):
 
             if challenge.visibility_mode == 'personal':
                 if not user_id:
-                    raise osv.except_osv(_('Error!'),_("Retrieving progress for personal challenge without user information"))
+                    raise UserError(_("Retrieving progress for personal challenge without user information"))
                 domain.append(('user_id', '=', user_id))
                 sorting = goal_obj._order
                 limit = 1
diff --git a/addons/gamification/models/goal.py b/addons/gamification/models/goal.py
index 415befbc8e8..48adf095ac5 100644
--- a/addons/gamification/models/goal.py
+++ b/addons/gamification/models/goal.py
@@ -24,6 +24,7 @@ from openerp.osv import fields, osv
 from openerp.tools import DEFAULT_SERVER_DATE_FORMAT as DF
 from openerp.tools.safe_eval import safe_eval
 from openerp.tools.translate import _
+from openerp.exceptions import UserError
 
 import logging
 import time
@@ -145,7 +146,7 @@ class gamification_goal_definition(osv.Model):
                 obj.search(cr, uid, domain, context=context, count=True)
             except (ValueError, SyntaxError), e:
                 msg = e.message or (e.msg + '\n' + e.text)
-                raise osv.except_osv(_('Error!'),_("The domain for the definition %s seems incorrect, please check it.\n\n%s" % (definition.name, msg)))
+                raise UserError(_("The domain for the definition %s seems incorrect, please check it.\n\n%s" % (definition.name, msg)))
         return True
 
     def create(self, cr, uid, vals, context=None):
@@ -450,7 +451,7 @@ class gamification_goal(osv.Model):
         for goal in self.browse(cr, uid, ids, context=context):
             if goal.state != "draft" and ('definition_id' in vals or 'user_id' in vals):
                 # avoid drag&drop in kanban view
-                raise osv.except_osv(_('Error!'), _('Can not modify the configuration of a started goal'))
+                raise UserError(_('Can not modify the configuration of a started goal'))
 
             if vals.get('current'):
                 if 'no_remind_goal' in context:
diff --git a/addons/gamification/wizard/grant_badge.py b/addons/gamification/wizard/grant_badge.py
index 513a1526c8b..b826bc4e563 100644
--- a/addons/gamification/wizard/grant_badge.py
+++ b/addons/gamification/wizard/grant_badge.py
@@ -21,6 +21,7 @@
 
 from openerp.osv import fields, osv
 from openerp.tools.translate import _
+from openerp.exceptions import UserError
 
 
 class grant_badge_wizard(osv.TransientModel):
@@ -40,7 +41,7 @@ class grant_badge_wizard(osv.TransientModel):
 
         for wiz in self.browse(cr, uid, ids, context=context):
             if uid == wiz.user_id.id:
-                raise osv.except_osv(_('Warning!'), _('You can not grant a badge to yourself'))
+                raise UserError(_('You can not grant a badge to yourself'))
 
             #create the badge
             values = {