Question

I want to put logic in the model rather than controller.

class UsersController < ApplicationController
  def somemethod
    d = User.methodinmodel
  end
end

class User < ActiveRecord::Base

  def methodinmodel
    "retuns foo"
  end
end

I get an error that there is no methodinmodel for the User model.

Why?

Answer 1

If you want to be able to call methodinmodel on the User class in general rather than a specific user, you need to make it a class method using self:

class User < ActiveRecord::Base
  def self.methodinmodel
    "returns foo"
  end
end

Your current method definition would only work if you called it on a user:

@user = User.create!
@user.methodinmodel  # Works.
User.methodinmodel   # Doesn't work.

Using the new implementation using self would allow you to call it like:

User.methodinmodel   # Works.