So i have a controller which subclasses down from the application controller. It defines a variety of protected methods, as well does the application controller. Now, if the application controller already defines those methods, I do not want them to be overwritten by its subclass. I've been trying things in this controller such as:
class SomeController < ApplicationController
protected
unless instance_methods.include? "some_method"
def some_method
end
end
However, using the Rails logger, I can still see that the some_method is being called.
Doing some further searching, I was able to figure it out :), thanks to the poster on this question here: How to judge whether a method has defined in a class?
class SomeController < ApplicationController
protected
unless method_defined? "some_method"
def some_method
end
end
Related
I need to create a controller instance from another controller for using its methods. When I creating
c = SomeController.new
c.some_method
some_method use params[], and then I have an error NoMethodError: undefined method 'parameters' for nil:NilClass.
How can I pass params to the controller?
The thing you are trying to do it not recommended any framework. You probable have some code that you wanted in multiple controllers. To achieve your desired behavior, extract the common code to library can call that in any controller you want.
You don't instantiate controllers in Rails - its done by the router when it matches a request to a route.
Its just not done because it violates the way MVC in Rails works - one request = one controller. You also need to pass the entire env hash from rack into the controller for it even work properly.
But really - don't. There are much better ways.
If you need to share a method between controllers there are better ways such as using inheritance:
class ApplicationController
def some_method
end
end
class FooController < ApplicationController
end
class BarController < ApplicationController
end
Or mixins:
# app/controllers/concerns/foo.rb
module Foo
def some_method
end
end
class BarController < ApplicationController
include Foo
end
class BazController < ApplicationController
include Foo
end
If you instead need to move a request from one controller action to another you should be redirecting the user.
Is it possible to make an includable controller action within a Rails Helper through an included block? I'm thinking something like this:
module XablauHelper
included do
def my_shared_action
true
end
end
end
Already tried doing it through class.eval block and through using like a class method i.e. self.my_shared_action but no success, I have already found a solution that is making a parent controller with the desired shared actions and inheriting from it, but for the sake of modular design I would like to make it a more "global" approach, so I could gemify my solution and reuse code, any suggestions that doesn't use inheritance?
Adding controller actions in a helper is probably the wrong choice, as these methods are intended for your views.
Consider using controller concerns instead, and including them where required. For example:
# in app/controllers/concerns/useful_functions_concern.rb
module UsefulFunctionsConcern
extend ActiveSupport::Concern
included do
rescue_from SomeException, with: :handle_access_denied
end
def useful_method
# ...
end
protected
def handle_access_denied
# ...
end
end
# in your controller
class XyzController < ApplicationController
include UsefulFunctionsConcern
def index
useful_method
end
end
Where common controller actions can be shared and the controllers have something in common e.g. they are all API controllers, also consider using inheritance to achieve this. For example:
# parent controller
class ApiController < ApplicationController
def my_shared_action
end
end
class SpecificApiController < ApiController
end
I'm relatively new to Rails and am working on creating a simple user authentication system to get to grips with how Rails works.
I'm currently at the point where I'd like to create some methods that I can use in my controllers like so:
is_logged? # => true
and
current_user_id # => 6
These would be used to interact with sessions, mainly so I'm not repeating myself in the controller.
Where would I define these functions and how would I include them in a controller?
Thanks a lot in advance for any help.
Method 1
You can define these method in helper files, inside app/helpers/my_module.rb. You can create a module there, put all the methods inside of it, and then include the modules in your control to use these method.
module MyMoule
def is_logged?
...
end
end
Then in you class include the module
class MyClassController < ApplicationController
include MyModule
def my_method
#Use it like this
logged_in = MyModule.is_logged?
end
end
Method 2
If you using session related stuff you can always put them inside application_controller.rb. And since all your controller will inherit ApplicationController the methods will be available to you.
class ApplicationController < ActionController::Base
def is_logged?
...
end
end
In your other controller you can use them directly.
class MyClassController < ApplicationController
def my_method
logged_in = is_logged?
end
end
I have three models.
users_controllers.rb
communities_controller.rb
community_tipics_controller.rb
I'm using the function called check_digit
def checkdigit
(transaction)
end
and I'm placing this in all the controllers.and calling it by before_filter.
But I think I'm wasting because I'm just pasting exactly the same code above to all of the controllers.
Where am I supposed to put it if my controller is using it in common?
Should I put it in controllers/application_controller.rb?
There are several ways of doing this , some possible ways are (If I'm to do this)
1st method
If this is a simple method used by controllers
inside application_controller.rb
private
def checkdigit
(transaction)
end
2nd method
if your function is used by a specific category , (this is normally I do very often), create a separate controller and have your all other controllers inherited by it
Ex: if your method used only my admins, and assuming you have some more methods like that
class AdminController < ApplicationController
layout 'admin'
private
def checkdigit
(transaction)
end
end
and
class UsersController < AdminController
end
3rd method
If your method is/will used by models/controllers etc.. consider making it a module
module CommonMethods
def checkdigit
(transaction)
end
end
class UsersController < ApplicationController
include CommonMethods
end
HTH
You can put it in helpers/application_helper.rb
You are correct, all common methods that all controllers need should be stored in the ApplicationController.
Furthermore, you should also keep common logic between all controllers in this controller.
Edit:
If they are just helpers, then you would put them where the helpers go, see the answer by #simone.
If I've got a method in a different controller to the one I'm writing in, and I want to call that method, is it possible, or should I consider moving that method to a helper?
You could technically create an instance of the other controller and call methods on that, but it is tedious, error prone and highly not recommended.
If that function is common to both controllers, you should probably have it in ApplicationController or another superclass controller of your creation.
class ApplicationController < ActionController::Base
def common_to_all_controllers
# some code
end
end
class SuperController < ApplicationController
def common_to_some_controllers
# some other code
end
end
class MyController < SuperController
# has access to common_to_all_controllers and common_to_some_controllers
end
class MyOtherController < ApplicationController
# has access to common_to_all_controllers only
end
Yet another way to do it as jimworm suggested, is to use a module for the common functionality.
# lib/common_stuff.rb
module CommonStuff
def common_thing
# code
end
end
# app/controllers/my_controller.rb
require 'common_stuff'
class MyController < ApplicationController
include CommonStuff
# has access to common_thing
end
Try and progressively move you methods to your models, if they don't apply to a model then a helper and if it still needs to be accessed elsewhere put in the ApplicationController
If you requirement has to Do with some DB operations, then you can write a common function (class method) inside that Model. Functions defined inside model are accessible across to all the controllers. But this solution does to apply to all cases.
I don't know any details of your problem, but maybe paths could be solution in your case (especially if its RESTful action).
http://guides.rubyonrails.org/routing.html#path-and-url-helpers