Does anyone know why I get
undefined method `my_method' for #<MyController:0x1043a7410>
when I call my_method("string") from within my ApplicationController subclass? My controller looks like
class MyController < ApplicationController
def show
#value = my_method(params[:string])
end
end
and my helper
module ApplicationHelper
def my_method(string)
return string
end
end
and finally, ApplicationController
class ApplicationController < ActionController::Base
after_filter :set_content_type
helper :all
helper_method :current_user_session, :current_user
filter_parameter_logging :password
protect_from_forgery # See ActionController::RequestForgeryProtection for details
You cannot call helpers from controllers. Your best bet is to create the method in ApplicationController if it needs to be used in multiple controllers.
EDIT: to be clear, I think a lot of the confusion (correct me if I'm wrong) stems from the helper :all call. helper :all really just includes all of your helpers for use under any controller on the view side. In much earlier versions of Rails, the namespacing of the helpers determined which controllers' views could use the helpers.
I hope this helps.
view_context is your friend, http://apidock.com/rails/AbstractController/Rendering/view_context
if you wanna share methods between controller and view you have further options:
use view_context
define it in the controller and make available in view by the helper_method class method http://apidock.com/rails/ActionController/Helpers/ClassMethods/helper_method
define it in a shared module and include/extend
Include ApplicationHelper in application_controller.rb file like this:
class ApplicationController < ActionController::Base
protect_from_forgery
include ApplicationHelper
end
This way all the methods defined in application_helper.rb file will be available in the controller.
You can also include individual helpers in individual controllers.
Maybe I'm wrong, but aren't the helpers just for views? Usually if you need a function in a controller, you put it into ApplicationController as every function there is available in its childclasses.
As said by gamecreature in this post:
In Rails 2 use the #template variable.
In Rails 3 use the controller method view_context
helpers are for views, but adding a line of code to include that helper file in ApplicationController.rb can take care of your problem. in your case, insert the following line in ApplicationController.rb:
include ApplicationHelper
As far as i know, helper :all makes the helpers available in the views...
Try appending module_function(*instance_methods) in your helper modules, after which you could directly call those methods on the module itself.
though its not a good practice to call helpers in controller since helpers are meant to be used at views
the best way to use the helpers in controller is to make a helper method in application_controller and call them to the controller,
but even if it is required to call the helper in a controller
then Just include the helper in the controller
class ControllerName < ApplicationController
include HelperName
...callback statements..
and call the helper methods directly to the controller
module OffersHelper
def generate_qr_code(text)
require 'barby'
require 'barby/barcode'
require 'barby/barcode/qr_code'
require 'barby/outputter/png_outputter'
barcode = Barby::QrCode.new(text, level: :q, size: 5)
base64_output = Base64.encode64(barcode.to_png({ xdim: 5 }))
"data:image/png;base64,#{base64_output}"
end
Controller
class ControllerName < ApplicationController
include OffersHelper
def new
generate_qr_code('Example Text')
end
end
hope this helps !
I had the same problem...
you can hack/bodge around it, put that logic into a model, or make a class specially for it. Models are accessible to controllers, unlike those pesky helper methods.
Here is my "rag.rb" model
class Rag < ActiveRecord::Base
belongs_to :report
def miaow()
cat = "catattack"
end
end
Here is part of my "rags_controller.rb" controller
def update
#rag = Rag.find(params[:id])
puts #rag.miaow()
...
This gave a catattack on the terminal, after I clicked "update".
Given an instantiation, methods in the model can be called. Replace catattack with some codes. (This is the best I have so far)
:helper all only opens helpers up to views.
This shows how to make a class and call it.
http://railscasts.com/episodes/101-refactoring-out-helper-object?autoplay=true
Try this to access helper function directly from your controllers view_context.helper_name
You can include your helper methods into a controller with a helper keyword syntax
class MyController < ApplicationController
helper ApplicationHelper
end
Related
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 have some Ruby methods certain (or all) controllers need. I tried putting them in /app/helpers/application_helper.rb. I've used that for methods to be used in views. But controllers don't see those methods. Is there another place I should put them or do I need to access those helper methods differently?
Using latest stable Rails.
You should define the method inside ApplicationController.
For Rails 4 onwards, concerns are the way to go. There was a decent article which can still be viewed via the Wayback Machine.
In essence, if you look in your controllers folder you should see a concerns sub-folder. Create a module in there along these lines
module EventsHelper
def do_something
end
end
Then, in the controller just include it
class BadgeController < ApplicationController
include EventsHelper
...
end
you should define methods inside application controller, if you have few methods then you can do as follow
class ApplicationController < ActionController::Base
helper_method :first_method
helper_method :second_method
def first_method
... #your code
end
def second_method
... #your code
end
end
You can also include helper files as follow
class YourController < ApplicationController
include OneHelper
include TwoHelper
end
You can call any helper methods from a controller using the view_context, e.g.
view_context.my_helper_method
Ryan Bigg response is good.
Other possible solution is add helpers to your controller:
class YourController < ApplicationController
include OneHelper
include TwoHelper
end
Best Regards!
Including helpers in controller will end-up exposing helper methods as actions!
# With new rails (>= 5)
helpers.my_helper_method
# For console
helper.my_helper_method
I want to use a method i have in my helper inside my controller.
I don't know how to use the view_context which i've heard could do the trick
As apneadiving said, make it a controller method and make that a helper method.
application_controller.rb
helper_method :do_stuff
def do_stuff
#this method is available in all controllers and views
I vote for #apneadiving's idea. But here goes:
class SomeController < ApplicationController
include SomeHelper
end
I would like to define a helper method, my_method, that will be available inside BuyersController methods (like index, create, e.t.c.).
I tried to define it in app/helpers/application_helper.rb but it didn't work:
undefined method `my_method' for #<BuyersController:0x26df468>
It should be in some shared place because I want to use it in other controllers also. This is why I tried app/helpers/application_helper.rb.
What is the right place to define it ?
It should be in app/controllers/application_controller.rb
The app/helpers/application_helper.rb is for shared view helpers.
You should include the application helper module in your application controller so that its methods will be available everywhere (all controllers and views) during a request.
class ApplicationController < ActionController::Base
helper ApplicationHelper
…
end
See the API docs for the helper method
Starting from Rails 3 you could also call view_context.my_method inside your controller
Expanding on the accepted answer, if you did want to share a controller method with views, helper_method seems well suited for this. Declaring a helper_method in the controller makes it accessible to the views.
class ApplicationController < ActionController::Base
helper_method :current_user, :logged_in?
def current_user
#current_user ||= User.find_by(id: session[:user])
end
def logged_in?
current_user != nil
end
end
Before rails 4, helpers with the same controller names will be only available in their controllers and views. Starting from rails 4, all helpers are available for all controllers (if you included them) and views. With that said, all helpers will be shared across your views.
Note: if you don't want this behavior for specific controllers, you can use clear_helpers, it will only include the helper with the same controller name.
For more information about using helpers see this
I created a helper method for some simple calculation. This helper method will just return an integer. I need the helper in both controllers and views.
Unfortunately, it work well in views but not in controllers. I get the undefined local variable or method error. How can I fix it?
Thanks all
In order to use same methods in both controller and views Add you method in application_controller.rb and make it helper methods.
For example
class ApplicationController < ActionController::Base
helper :all # include all helpers, all the time
#protect_from_forgery # See ActionController::RequestForgeryProtection for details
helper_method :current_user
def current_user
session[:user]
end
end
Now you can use method current_user in both controllers & views
I use a following solution. Because I think helper's methods shoud be stored in an appropriate helper module.
module TestHelper
def my_helper_method
#something
end
end
class SomeController < ApplicationController
def index
template.my_helper_method
end
end