undefined method `find_all_by_X'

Question

Currently maintaining some old Ruby server and got the following error in Log:

NoMethodError (undefined method `find_all_by_X_ID' for #<Class:0x00000005555555>):
  app/controllers/some_controller.rb:10:in `buggy_function'

When viewed the faulty line in code of the buggy function is looks like this:

Hash[S.find_all_by_X_ID(TaskRun.select(:x_id).uniq.where(y_id: @y.Y_ID).map(&:x_id)).map { |s| [s.S_IDENTIFIER, s.X_ID] }]

To be frank, I'm new to Ruby, and wondering how implementing this find_all_by_X query would be the best, and why it appears as it should be automatic (as it has to do with the model component).

We're working on Ruby version 2.

Answer 1

It seems that find_all_by was deprecated in Rails 4 ...

Internally Rails implemented methods like find_all_by_x_id using method_missing (the method is actually defined dynamically through metaprogramming) ... but you don't have to worry about that for your use-case.

In terms of your code, if we extract the x_ids list into a variable:

x_ids = TaskRun.select(:x_id).uniq.where(y_id: @y.Y_ID).map(&:x_id)

Then you have this line that you need to rewrite:

S.find_all_by_X_ID(x_ids)

You can rewrite this as:

S.where(x_id: x_ids)

See https://stackoverflow.com/a/23921890/2981429