Last modified: 2009-01-06 22:18:12 UTC
MediaWiki contains a few calls to "exit" after generating pages that otherwise would be cleanly generated. Beginning with PHP5, this is no longer necessary as an error-handling mechanism. The attached patch replaces all such exit calls with exception 'throw' and adds a try/catch framework to index.php This has the beneficial side effect of making MW far more easily customized via minor adjustments to index.php
Created attachment 3330 [details] Patch implements try/catch duplicating present function It is possible that the "catch" should come earlier in index.php -- is it really desirable to skip all final page-handling when page-generation hits a snag? This patch implements the exception as if we really do want to do the equivalent of "exit" under default conditions... but that may not be correct.
If exceptions are used, they should presumably be MWExceptions and give descriptive error messages (although I suppose it doesn't make much difference).
My impression is that those are places where it really _oughtn't_ to be exiting, but rather things should be allowed to close out gracefully. So rather than using exceptions of any kind, I'd rather see them changed to just exit (this may require fixing code that uses them that makes the assumption they cause exits).
Brian, I presume you mean "changed to just return". Yes, the whole issue is how to close out gracefully after giving a "nice" wikitext error message to the user, an error that has stopped normal page processing in its tracks (e.g. "no permission".) It would be great if someone with more MW code experience is able to discern an appropriate return-based strategy that doesn't cause hiccups to the entire code base. Any takers? In the meantime, I'm happy with exception-throwing as an interim improvement over the current exit "strategy" :) If this bugfix is to use MWExceptions, we would a) need a new type of MWException (producing no report); and b) be assured that catching MWExceptions at the outer level is not an issue. As for descriptive error messages, sure, that can be done. Simetrical is correct that it doesn't make much difference -- the message would be invisible to the user, and solely for developer understanding. In these cases, the code has already created informative wikitext error messages for the user; there's nothing more to be created for the user. The sole purpose of this change is to enable proper cleanup. In my case, all of MW is wrapped inside another package, so "proper cleanup" has rather large significance :)
Done in r45314, except for the index.php stuff
those bits were changed a bunch in r45320
