[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, 4 insertions, 3 deletions

diff --git a/addons/base_import_module/models/ir_module.py b/addons/base_import_module/models/ir_module.py
index 02965ef6074..3e35de2b0a1 100644
--- a/addons/base_import_module/models/ir_module.py
+++ b/addons/base_import_module/models/ir_module.py
@@ -8,6 +8,7 @@ import openerp
 from openerp.osv import osv
 from openerp.tools import convert_file
 from openerp.tools.translate import _
+from openerp.exceptions import UserError
 
 _logger = logging.getLogger(__name__)
 
@@ -27,7 +28,7 @@ class view(osv.osv):
         unmet_dependencies = set(terp['depends']).difference(installed_mods)
         if unmet_dependencies:
             msg = _("Unmet module dependencies: %s")
-            raise osv.except_osv(_('Error !'), msg % ', '.join(unmet_dependencies))
+            raise UserError(msg % ', '.join(unmet_dependencies))
 
         mod = known_mods_names.get(module)
         if mod:
@@ -79,7 +80,7 @@ class view(osv.osv):
         if not module_file:
             raise Exception("No file sent.")
         if not zipfile.is_zipfile(module_file):
-            raise osv.except_osv(_('Error !'), _('File is not a zip file!'))
+            raise UserError(_('File is not a zip file!'))
 
         success = []
         errors = dict()
@@ -88,7 +89,7 @@ class view(osv.osv):
             for zf in z.filelist:
                 if zf.file_size > MAX_FILE_SIZE:
                     msg = _("File '%s' exceed maximum allowed file size")
-                    raise osv.except_osv(_('Error !'), msg % zf.filename)
+                    raise UserError(msg % zf.filename)
 
             with openerp.tools.osutil.tempdir() as module_dir:
                 z.extractall(module_dir)