[Krang-devel] new tagging system

[Michael P. <mp...@pl...>]

Hello all,

If you've been following krang-svn you would have noticed a lot of 
commits by me in the past few weeks that all deal with adding tags to 
Krang stories and media.

I should have discussed this earlier in case anyone had some 
input/feedback but I have to admit that I let real life get in the way 
(vacations, traveling, conferences, court case, work deadlines, 
misbehaving internet connections, etc). So I'm trying to rectify that 
situation now :)

Basically it adds simple tags story and media that can be accessed like

   @tags = $story->tags;
   @tags = $media->tags;

And updated like so:

   $story->tags(['foo', 'bar']);
   $media->tags([]);

And searched like:

   @stories = Krang::Story->find(tag => 'foo');

David Kaufman asked me off list what are the benefits/differences 
between these tags and having tags in your element library. We actually 
used element library tags for a long time and those worked pretty well. 
But here a couple of places where they fell short and where the new tags 
will work better:

* Elements, while searchable in code aren't searchable in the UI because 
they are custom to each setup. These new tags are available for 
searching on the advanced tabs of the find screens for stories and media.

* Not as easy to use. Compare
   @tags = $story->element->child_data('tags')
   and
   @tags = $story->tags();

And it's not just from the Perl code, but from SQL as well since tags 
are stored in story_tag or media_tag table and can be manipulated much 
more easily than if they are stored as Storable array binary blobs in 
the element table.

* Tagging has become pretty universal in web systems, especially CMSs 
and it's a shame that each element library would need to re-invent this 
wheel. This also makes them more prominent on the edit screens in the 
same spot as title and slug instead of possibly buried under a complex 
element that needs an extra step to edit.

* Easier to extend via addons. Our main addon extends Krang with lots of 
other objects (Events, Groups, Mailings, Contributions, etc) and we 
wanted to tag those as well. And we've written a UI to manage these tags 
across all of these different objects. This would have been hard to do 
if updating a tag meant crawling through lots of stories and updating 
their elements. Instead we use some pretty simple SQL to manipulate them.

So please try it out and tell me what you think? I'm planning on tagging 
a version for 3.21 so that we can test it out this weekend.

-- 
Michael Peters
Plus Three, LP