Howdy, I've just committed r13835, which documents Callbacks. Yay! A few notes:
* Tim, you earlier said: > I could arrange for Callbacks to only apply to methods called by the > applicationi, and not to 'nested calls'. That's a fairly major change > after this length of time but given the limited use Callbacks have had, > and the lack of documentation, it's not out of the question. > > The downside is that to intercept all fetched rows in a general way > (like some kind of plugin utility module might want to do) you now have > to add callbacks for 7 $sth fetch* methods and 6 $dbh select* methods. > > Is that really preferable? And I replied: > Well, yes. But if there were 'fetch*' and 'select*' keys that could go to all > of them at once, that would be cool, too. I don't know if you've changed anything here. Even earlier, you wrote: > If you're applying a callback to the "fetch" method and then your code > calls fetchrow_hashref, for example, how do you know if the driver's > fetchrow_hashref() method calls fetch() or fetchrow_arrayref()? > > The fetch and fetchrow_arrayref method are typically aliased by the > driver, but they're two separate methods from the DBI dispatcher's point > of view. > > Applying the same callback to both is a reasonable approach. I'm not sure what you decided to do about this, either. But I do think that whatever side-effects of such dispatch there are should be carefully documented as well. * I tried to include some useful examples, but one is DBD::Pg-specific and another is DBD::mysql-specific. Hope that's okay. * I didn't mention anything about the future possibility of post-method-call callbacks or an OO interface for setting up callbacks. I look forward to your edits and comments, and let me know if I can help with anything else for this release. Best, David
