[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.

1 files changed, 3 insertions, 5 deletions

diff --git a/addons/analytic_user_function/analytic_user_function.py b/addons/analytic_user_function/analytic_user_function.py
index 4337e7a72e2..855ee4ced47 100644
--- a/addons/analytic_user_function/analytic_user_function.py
+++ b/addons/analytic_user_function/analytic_user_function.py
@@ -22,6 +22,7 @@
 from openerp.osv import fields,osv
 from openerp.tools.translate import _
 import openerp.addons.decimal_precision as dp
+from openerp.exceptions import UserError
 
 class analytic_user_funct_grid(osv.osv):
     _name="analytic.user.funct.grid"
@@ -105,10 +106,7 @@ class hr_analytic_timesheet(osv.osv):
             if not a:
                 a = r.product_id.categ_id.property_account_expense_categ.id
             if not a:
-                raise osv.except_osv(_('Error!'),
-                        _('There is no expense account defined ' \
-                                'for this product: "%s" (id:%d)') % \
-                                (r.product_id.name, r.product_id.id,))
+                raise UserError(_('There is no expense account defined for this product: "%s" (id:%d)') % (r.product_id.name, r.product_id.id,))
             # Compute based on pricetype
             if unit_amount:
                 amount_unit = self.on_change_unit_amount(cr, uid, ids,
@@ -134,7 +132,7 @@ class hr_analytic_timesheet(osv.osv):
                 if not a:
                     a = r.product_id.categ_id.property_account_expense_categ.id
                 if not a:
-                    raise osv.except_osv(_('Error!'),
+                    raise UserError(
                             _('There is no expense account defined ' \
                                     'for this product: "%s" (id:%d)') % \
                                     (r.product_id.name, r.product_id.id,))