DAO::update hook

[Horscht]

According to the Tech Manual Hook List any DAO function calling DAO::update will trigger a hook called "[Anything]DAO::​[Any function calling DAO::​update]".

ArticleDAO::updateArticle(&$article) calls DAO::update but no hook called ArticleDAO::updateArticle is triggered as I expected.
I tried my code with other randomly chosen hooks and was able to get calls to my callback function, so how do I get it to work with DAO::update?

[Horscht]

I found the comment in the source that pointed out the hook is called articledao::_updatearticle( why lower case? why the underscore?).
The underscore makes me curious. Am I not supposed to use this hook? I can register it for my plugin, but when it should be triggered it gets unregistered and my callback function is never called.
Weird stuff... what's going on here?

[asmecher]

Hi Horscht,

The tech reference is unfortunately a little out of date. I'd be happy to help you out here.

The hook names for implicitly-named hooks (like the one you're looking for) are all dropped to lower case because different versions of PHP have different case sensitivities (PHP4 is lower case, IIRC, and PHP5 is not). To make them all behave the same way WRT hook names we convert them to lower case.

The "_" is there because we wanted to disambiguate between implicitly-named hooks (ones where the name is generated by looking at the debug_backtrace, such as the one you're looking for) and explicitly-named ones (where we've named the hooks ourselves), to avoid clashes.

Could you describe what you're using the hook to do? What category is your plugin loading in?

Regards,
Alec Smecher
Public Knowledge Project Team

[Horscht]

RIght now the plugin extends GenericPlugin and the hook is supposed to be used to keep a repository up to date. Basically it takes the article and supplementary files and stuffs everything into a .tar.gz.

[asmecher]

Hi Horscht,

It sounds like you're on the right track. When you say that the hook gets unregistered, do you mean that it's just never called when you expect it to be? I tend to debug by dropping "echo" or "die" statements in -- there are two places to start with this. One is in your plugin registration function, where you register for the hook, to make sure it's getting registered before the article update is called. If that looks OK, the next place is perhaps in DAO.inc.php where you expect the hook to be called -- it sounds like you've already tried dumping the hook name there. A third is in the HookRegistry::call function to list out hooks when they're called. If this doesn't make sense, or you've already tried this, let me know and I'll walk you through more.

Regards,
Alec Smecher
Public Knowledge Project Team

[Horscht]

Well registering the Plugin works. Right after I enable it in the journals plugin menu the hook is listed in Hookregistry::getHooks().

Then I try to trigger the hook but when ArticleDAO::updateArticle() is called my hook isn't listed anymore in HookRegistry::getHooks().

I checked for HookRegistry::clear() and HookRegistry::setHooks() calls between the registering of my plugin and the call to updateArticle() and there are none.
What other functions modify the list of registered hooks?

[asmecher]

Hi Horscht,

I'll bet the plugin isn't installed in the database. Is there an entry for it in the "versions" table?

If not, you should be able to get it added by running the upgrade script (php tools/upgrade.php upgrade). Please back up your database before doing this, just in case some prior problem left it in an uncertain state. Alternately, use another plugin's entry as an example.

Regards,
Alec Smecher
Public Knowledge Project Team

[Horscht]

Hi.

Wow, that did the trick.
Thanks for your help. I really appreciate it.

[asmecher]

Hi Horscht,

No problem, and good luck. If you think the plugin might be broadly useful, please consider posting it to the plugin gallery. (Also, since you mentioned keeping a repository up to date -- have you seen the SWORD plugin?)

Regards,
Alec Smecher
Public Knowledge Project Team