Where should I start looking to create a plugin that extends Rails 3 finds?

Question

Prior to Rails 3, creating a plugin to extend find was relatively easy: basically override the find method itself in ActiveRecord::Base , calling super if needed.

Now that Arel is being used in Rails 3, (specifically I'm using Rails 3.1), how would I go about doing something similar? The problem is that many of the old find methods are deprecated in favor of scopes like where , order , limit , etc. At what point(s) in the Rails source should I try to override the default behavior?

I'm sure it's going to be a bit more convoluted than this, but the closest thing I can find that seems like it might be appropriate is the construct_finder_arel method in ActiveRecord::Base .

Answer 1

After digging through Rails source, regardless of Arel being used, find_by_sql method is called on whatever model is performing the find. This can be extended via alias_method_chain as follows:

find_by_sql_with_customization(*args)
  results = find_by_sql_without_customization
  # do something with results here
  results
end

alias_method_chain :find_by_sql, :customization