@jferris @benorenstein I agree in general on callbacks being evil(most of the times) but consider this example:
We have a model NewsSource which represents a blog with corresponding info like author email, site_url, title, etc.
Every news source also has a rss feed. The feed could be atom, rss, or whatever type.
There is a parser in the app that fetches feeds periodically and parses the posts.
Initially we kept feed_url value in news_source itself but after constructing parsers certain way we decided to extract feed data out to have some validations and other checks.
So at the end we have two very tightly coupled models:
class NewsSource
has_one :feed
end
class Feed
belongs_to :news_source
end
Every time we create or update a news_source we need create or update corresponding nested/child object feed and this is where before_create :generate_feed and before_update :update_feed callbacks came in handy.
Ideally we should’ve used accepts_nested_attributes_for but in our case the client apps(namely our Ember.js admin panel) doesn’t send nested objects to our API endpoints so we had to wrap it this way.
What do you think, is this one of those “exception” cases when it’s ok to use callbacks or we can somehow improve it?
Thanks.