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.
These commits were introduce mostly at revision
1849.1.1 revid:hmo@tinyerp.com-20081111052750-zqzvr6oaihvt103t
in an attempt to fix an issue with transactions
originating from FTP connections.
This was wrong: the virtual FTP filesystem should
perform its own transaction management for each
operation, just like the RPC layer does it for
each request. Forcing a commit in the business
code during the course of a normal transaction is
totally *forbidden*!
In addition, the FTP layer now properly manages
its transactions, so the commit calls were useless
anyway.
bzr revid: odo@openerp.com-20111130120239-5fcavvpd14w056zb
There is commit commands inside document, to prevent from partially
writting data (eg. filestore and the db). Thus, the atomicity of the
transaction is broken.
bzr revid: p_christ@hol.gr-20100701175131-8v8xyosvz8nly0pi
Goffin Simon