I’m stumped and could use some help/advice – time to show your mad
hackr skillz…
Please forgive the length, there’s some needed background involved.
Background
SnS TextAsset models track their dependencies (each model parses its
content and identifies <r:javascript> or <r:stylesheet> tags within).
Easy.
Then, when any model is updated, it announces this to all the other
instances who check their dependencies and, if they depended on the
updated model, adjust their own effectively_updated_at date. So far,
still easy.
The Problem
Saving the effectively_updated_at date – not so easy. TextAsset models
have callbacks – none of which should fire when only saving
effectively_updated_at.
Specifically, these are:
* Rails automatic timestamps (created_at, updated_at)
* before_update and before_create callbacks (via Radiant's
UserActionObserver to set created_by and updated_by)
* My own before_save callback which parses the content to update its
own dependencies (mentioned above)
* My own after_save callback to announce to the other models that
this one's been changed (mentioned above)
Current Solution
The current solution is to store effectively_updated_at in a separate
model with a has_one relationship to its TextAsset. That way changes to
the date are done directly through that sub-model and so doesn’t trigger
the callbacks on the related TextAsset.
This works but it really bugs me having a separate table just for one
field (a field that really belongs to another model).
Help?
Can anyone think of some clever solution that will let me move this
attribute into TextAsset?
How could I update and save a TextAsset’s effectively_updated_at
attribute without waking up those callbacks?
Or am I just being too picky?
Ideas
I’m open to anything here, really. My current ideas include:
* Make the TextAsset model explicitly handle all the above callbacks
(no more auto timestamps, no more using Radiant's built-in
observers). And then, in those callbacks, inspect an instance
variable flag (say, @exit_callbacks) to end each routine. It's a
bit messy but it also replaces some mess in dealing with the extra
table. Mostly I don't like that it ignores Radiant's and Rails
built-in tools. I'm also not sure how to make current_user
available to a TextAsset (but that's probably not hard).
* Add some way to disable callbacks on a particular instance (like
maybe:
http://github.com/cjbottaro/without_callbacks/tree/master). Seems
neat but also sounds like a lot of code for one attribute. I've
never used it either so I'm not sure how reliable it is or if it's
solid across different Radiant/Rails versions.
* Save to the effectively_updated_at column directly using the
ActiveRecord's #connection method and SQL commands. Never done
this before and it sounds like, well, yuck (but maybe I don't
understand it well enough either). And could this even be done in
a db-agnostic way?
* Your idea here...
Thanks,
Chris
here’s an explanation: