Rails: How to get the model class name based on the controller class name?

Question

class HouseBuyersController < ...
  def my_method
    # How could I get here the relevant model name, i.e. "HouseBuyer" ?
  end
end

malclocke · Accepted Answer · 2011-07-21T02:35:29.453

195

This will do it:

class HouseBuyersController < ApplicationController

  def index
    @model_name = controller_name.classify
  end

end

This is often needed when abstracting controller actions:

class HouseBuyersController < ApplicationController

  def index
    # Equivalent of @house_buyers = HouseBuyer.find(:all)
    objects = controller_name.classify.constantize.find(:all)
    instance_variable_set("@#{controller_name}", objects)
  end

end

edited Jul 21 '11 at 02:35

answered Jul 21 '11 at 01:08

malclocke

5,192
4
20
9

@model_name = controller_name.classify # returns "HouseBuyers" thanks! – Peter Ehrlich Jan 28 '12 at 19:36
Depending on your needs, (this question doesn't specify any details), you can do `controller_name.sub('_', ' ').titleize` to get "House Buyers". – user664833 Feb 19 '12 at 03:31
It might be good to move the logic (for getting the model class) into a separate utility method. Even better if the result is stored in a constant, to speed up access. You can use `new.controller_name.classify.constantize` in the class definition. – Kelvin Jun 07 '13 at 17:56
I think it's worth noting that this will even work in the application controller depending on which controller inherits from it. – Dennis Hackethal Dec 16 '13 at 22:09
this solution doesn't work with namespaces. See my solution below. – hachpai Mar 26 '15 at 19:39

Matt · Answer 2 · 2014-09-18T19:14:54.363

46

If your controller and model are in the same namespace, then what you want is

controller_path.classify

controller_path gives you the namespace; controller_name doesn't.

For example, if your controller is

Admin::RolesController

then:

controller_path.classify # "Admin::Role" # CORRECT
controller_name.classify # "Role"        # INCORRECT

edited Sep 18 '14 at 19:14

answered Sep 18 '14 at 18:30

Matt

20,108
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This should be the accepted answer as it is more generally valid while containing the non-namespaced version as a sub-answer. – Andreas Gebhard Sep 20 '22 at 14:03

score 6 · Answer 3 · answered Feb 02 '11 at 01:50

It's a bit of a hack, but if your model is named after your controller name then:

class HouseBuyersController < ApplicationController
  def my_method
    @model_name = self.class.name.sub("Controller", "").singularize
  end
end

... would give you "HouseBuyer" in your @model_name instance variable.

Again, this makes a huge assumption that "HouseBuyersController" only deals with "HouseBuyer" models.

score 4 · Answer 4 · answered Mar 26 '15 at 19:40

4

For namespaces working:

def resource_class
 controller_path.classify.constantize
end

answered Mar 26 '15 at 19:40

hachpai

196
12

stoffus · Answer 5 · 2013-09-26T08:47:40.683

0

The accepted solution did not work for me as my controller and model was namespaced. Instead, I came up with the following method:

def controllers_model
  (self.class.name.split('::')[0..-2] << controller_name.classify).join('::')
end

edited Sep 26 '13 at 08:47

answered Sep 26 '13 at 08:32

stoffus

1
1

score -1 · Answer 6 · answered Feb 02 '11 at 01:37

This is not possible if you are using the default MVC, which your code doesn't seem to follow. Your controller seems to be a model but maybe you just got a type there. Anyway, controllers and models are fundamentally separated in Rails MVC so controllers cannot know which model they are associated with.

For example you could have a model named post. This can have a controller posts_controller or could have a controller like articles_controller. Rails only knows about models when you def the actual code in the controller such as

def index
  @posts = Post.all
  @posts = Article.all
end

In rails standard controllers there is no way to know what the model is.

Rails: How to get the model class name based on the controller class name?

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