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'm confused by the rails documentation that I'm reading here. In particular, this sentence:
By default, each controller will include all helpers. These helpers
are only accessible on the controller through .helpers
What is this .helpers that it is referring to? I have a helper defined in app/helpers/areas_helper.rb:
module AreasHelper
def my_helper
puts "Test from helper"
end
end
I would like to use this helper in app/controllers/locations_controller.rb:
class LocationsController < ApplicationController
def show
helpers.my_helper
end
end
However, I get a method undefined error. How is this .helpers supposed to be used?
I know there are other ways to get access to helpers in controllers, but I'm specifically asking about this piece of documentation and what it's trying to say.
You're meant to include the helper class in the controller:
#app/controllers/locations_controller.rb
class LocationsController < ApplicationController
include AreasHelper
def show
my_helper
end
end
This feature was introduced in Rails 5 with following PR
https://github.com/rails/rails/pull/24866
So, we can use this feature from Rails 5 and onwards and not in Rails 4.x.
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
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