Rails core - May 2010 - What is the deal with Controller additions and helper methods!?

I have ben struggling the past two days getting a this tiny piece of
functionality to work without any success :(

Trying to add a simple helper method to my views in order to ensure
links are only displayed if the user has the proper rights to access
that functionality.

      def show_link(object, label = nil)
        label ||= auth_labels[:show]
        if can?(:read, object)
          link_to(label, object)
        end
      end

But using link_to from within this context, somehow I don''t have
access to the controller variable used internally, fx in url_for.

      def url_for(options = {})
        ...
        when :back
          escape = false
          controller.request.env["HTTP_REFERER"] ||
''javascript:history.back()''
        else
        ...
      end

If I output self in the show_link method, I can see that my current
context of self is ProjectsController, so I guess it makes sense that
I don''t have a method controller inside a controller?
I access my helper method from here:

# index.html.erb
<%= show_link project %>

And the setup

if defined? ActionController
  ActionController::Base.class_eval do
    AuthAssistant::ViewHelpers::AuthLink
  end
end

# module AuthAssistant::ViewHelpers::AuthLink

      def self.included(base)
 
base.helper_method :create_link, :delete_link, :edit_link, :show_link
 
base.helper_method :new_link, :destroy_link, :update_link, :read_link
      end

-- 
You received this message because you are subscribed to the Google Groups
"Ruby on Rails: Core" group.
To post to this group, send email to rubyonrails-core@googlegroups.com.
To unsubscribe from this group, send email to
rubyonrails-core+unsubscribe@googlegroups.com.
For more options, visit this group at
http://groups.google.com/group/rubyonrails-core?hl=en.

> But using link_to from within this context, somehow I don''t have
> access to the controller variable used internally, fx in url_for.
That''s because the controller itself has its own implementation of
url_for, if you attempt to reuse those helpers in the controller it''s
just not going to work.  Given that link_to is defined in the same
module as the view''s url_for, you probably won''t be able to
get this
working without serious hacks or code duplication.  But I''d question
what you''re trying to do here, why are your controllers generating
html without using views?



-- 
Cheers

Koz

-- 
You received this message because you are subscribed to the Google Groups
"Ruby on Rails: Core" group.
To post to this group, send email to rubyonrails-core@googlegroups.com.
To unsubscribe from this group, send email to
rubyonrails-core+unsubscribe@googlegroups.com.
For more options, visit this group at
http://groups.google.com/group/rubyonrails-core?hl=en.

On 14 May 2010 07:22, Michael Koziarski <michael@koziarski.com> wrote:
> But I''d question what you''re trying to do here, why are
your controllers
> generating html without using views?
>
A "sometimes" use-case is putting a link using link_to in the flash.

-- 
Ryan Bigg / Radar

-- 
You received this message because you are subscribed to the Google Groups
"Ruby on Rails: Core" group.
To post to this group, send email to rubyonrails-core@googlegroups.com.
To unsubscribe from this group, send email to
rubyonrails-core+unsubscribe@googlegroups.com.
For more options, visit this group at
http://groups.google.com/group/rubyonrails-core?hl=en.

I''d recommend render_to_string :inline for this case.

Yehuda Katz
Architect | Engine Yard
(ph) 718.877.1325


On Thu, May 13, 2010 at 2:31 PM, Ryan Bigg <radarlistener@gmail.com>
wrote:
>
> On 14 May 2010 07:22, Michael Koziarski <michael@koziarski.com>
wrote:
>
>> But I''d question what you''re trying to do here, why
are your controllers
>> generating html without using views?
>>
>
> A "sometimes" use-case is putting a link using link_to in the
flash.
>
> --
> Ryan Bigg / Radar
>
>  --
> You received this message because you are subscribed to the Google Groups
> "Ruby on Rails: Core" group.
> To post to this group, send email to rubyonrails-core@googlegroups.com.
> To unsubscribe from this group, send email to
>
rubyonrails-core+unsubscribe@googlegroups.com<rubyonrails-core%2Bunsubscribe@googlegroups.com>
> .
> For more options, visit this group at
> http://groups.google.com/group/rubyonrails-core?hl=en.
>
-- 
You received this message because you are subscribed to the Google Groups
"Ruby on Rails: Core" group.
To post to this group, send email to rubyonrails-core@googlegroups.com.
To unsubscribe from this group, send email to
rubyonrails-core+unsubscribe@googlegroups.com.
For more options, visit this group at
http://groups.google.com/group/rubyonrails-core?hl=en.

All I actually wanted to do was to add some helper methods for my
views.
I kind of "solved" the problem by rethinking my approach, as I could
see I had gone down a "blind alley".

module ApplicationHelper
  def self.auth_assist_helpers
    include AuthAssistant::ViewHelpers
  end
end

module AuthAssistant
  module ViewHelpers
    include AuthAssistant::ViewHelpers::AuthLink
    include AuthAssistant::ViewHelpers::RestLink
    include AuthAssistant::ViewHelpers::AuthMenuItem
  end
end

--
In my Rails app I can now do the following to have them added. Don''t
know how to do a similar feat from my gem, since there is a loading/
timing issue then?

module ApplicationHelper
  auth_assist_helpers
end

and all the methods are included into ApplicationHelper and hence
available for my views, and link_to works as expected from within this
context. Not sure if this is the "right" approach however, polluting
the ApplicationHelper seems kind of crude. How is the UrlHelper
integrated and made available for the views I wonder?

I used the previous approach, coz that was what I had seen in code
elsewhere, such as in cancan, devise etc. Adding method to
ActionController and certain methods made available as helper methods
using helper_method :xxxx

Thanks!

> That''s because the controller itself has its own implementation of
> url_for, if you attempt to reuse those helpers in the controller
it''s
> just not going to work.  Given that link_to is defined in the same
> module as the view''s url_for, you probably won''t be able
to get this
> working without serious hacks or code duplication.  But I''d
question
> what you''re trying to do here, why are your controllers generating
> html without using views?
>
> --
> Cheers
>
> Koz
>
-- 
You received this message because you are subscribed to the Google Groups
"Ruby on Rails: Core" group.
To post to this group, send email to rubyonrails-core@googlegroups.com.
To unsubscribe from this group, send email to
rubyonrails-core+unsubscribe@googlegroups.com.
For more options, visit this group at
http://groups.google.com/group/rubyonrails-core?hl=en.