On Tue, Mar 02, 2010 at 05:08:21PM -0800, David E. Wheeler wrote: > Howdy, > > I've just committed r13835, which documents Callbacks. Yay! A few notes:
Great. Thanks! > * 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. Nope. No changes there. > 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. I was tempted to leave "The cool thing is" but opted to drop it as it doesn't match the tone of the rest of the docs - although they are rather dry :) I've made assorted edits and added some extra info. A sanity check would be most welcome. Thanks again David! Tim.
