write controllers code in model rails

Question

I have a ConversionRate model

class ConversionRate < ActiveRecord::Base
end

I want to move to model my controller method find_something

class ConversionRatesController < ActionController::Base
  #....
  def find_something (param)
    rate = ConversionRate.where(:param=> param)
  end
 end

How do I do this? I am thinking of something like this

class ConversionRate < ActiveRecord::Base
 def self.find_something(param)
   return self.where(:param=> param)
end

You can directly call .where method on model. Why again you are defining a method for it? — Narasimha Reddy - Geeker
– Narasimha Reddy - Geeker, Commented Sep 19, 2017 at 12:40
@user2950593 if the answer was fine, you can close this question by choosing it. If you have any further doubt, please comment — mabe02
– mabe02, Commented Oct 10, 2017 at 11:08

mabe02 · Accepted Answer · 2017-09-19 12:42:27Z

2

It seems that you have already found your solution:

class ConversionRate < ActiveRecord::Base
 class << self
    def find_something(param)
     where(:param=> param)
    end
  end
end

An alternative could be to use a scope:

class ConversionRate < ActiveRecord::Base
  scope :find_something, ->(param) { where(param: param) }
end

Then you can call it from the controller like ConversionRate.find_something(params)

I would encourage the first approach if you need to perform some validation on your param, otherwise the second is very straightforward.

answered Sep 19, 2017 at 12:42

mabe02

2,7642 gold badges22 silver badges39 bronze badges

Sign up to request clarification or add additional context in comments.

7 Comments

user2950593 Over a year ago

Thanks! another quetion: how do I define method for instance of model? For example I have cr= ConversionRate.new; cr.param = "123"; I want to write cr.find_another_param

mahemoff Over a year ago

Or def self.find_something(param)

mabe02 Over a year ago

I guess that this is another question.. it would be a little confusing to add to the same answer. You can close this one and open another to keep the topic distinguished

SRack Over a year ago

@mabe02 - what's the advantage of the singleton method, rather than using a standard class method (i.e. @mahemoff's def self.find_something ) or your scope? Asking out of curiosity.... not suggesting you're wrong or anything.

mabe02 Over a year ago

this pretty outdated answer provides a good overview stackoverflow.com/a/11816412/5687152 With scope you return a subset of an ActiveRecord::Relation, with a self.something method you can return what you prefer. I prefer to enclose class methods inside class << self ; end for clarity, but there is no difference with several def self.something; end

|

Collectives™ on Stack Overflow

write controllers code in model rails

1 Answer 1

7 Comments

Your Answer

Linked

Hot Network Questions

Collectives™ on Stack Overflow

1 Answer 1

7 Comments

Your Answer

Sign up or log in

Post as a guest

Linked

Related