constant caching, modules and STI

rubyonrails-talk
1

Hi there, I've been following one of the recipes in the Advanced Rails Recipes books, and have arrived for my own particular needs at this scenario:

I want to cache some options data in constants at loadtime (as per the recipe) for dropdown menus in a form All of the different options are in a single table and use STI.

I have the following module in my initializer folder, with caches_constant called on the main activerecord data class (RnData):

2

Ideally I would like something along the lines of:

RnData::RN_DATA RnData::RN_AUTO RnData::RN_INCOME or just RnAuto::OPTIONS RnIncome::OPTIONS

as long as it has the right info for the subclass in it, and not just the parent inherited across all subclass.

So, I'm wondering if there's a way to write this so that it will run caches_constant for subclass, or do I have to include the caches_constants line in all my subclasses?

The inherited hook as you found below would do the trick. feels a bit
overkill to me - sometimes there is such a thing as too DRY.

I've replacing caches_constants with this which seems to work, but I'm worried I may be overwriting something critical in activerecord:

class RnData < ActiveRecord::Base def self.inherited(subclass)     subclass.caches_constants end end

at the very least call super here or you will be overwriting stuff here.

Fred

3

The inherited hook as you found below would do the trick. feels a bit
overkill to me - sometimes there is such a thing as too DRY.

Yeah but I have at least 17 subclasses that are basically empty stubs for looking up the data and setting relationships on a model.

4

oh, and thanks for the 'super' I always wondered what that did :slight_smile: