How to explore the environment?

[Fritz Trapper]

It's my first rails project and something is broken: my action
controllers can't access methods defined in the helper modules.

The only thing, I successfully verified (by setting a debugger statement
at the very beginning of the helper modules) is, that the helper modules
get loaded before the action controller is called.

None the less, the methods defined in the helpers, are unknown to the
action controllers.

I can fix the problem by duplicating the helper methods in the
controller module, but that's a hack.

Any idea, how to find the reason?
--
Posted via http://www.ruby-forum.com/.

[pharrington]

http://api.rubyonrails.org/classes/ActionController/Helpers/ClassMethods.html#M000490
(the documentation sort-of lies, as the helper() method does not
actually "include" the specified module)

helper WhateverHelper will give the view access to the helper module's
instance methods
include WheteverHelper will, being plain-old-Ruby, include the
WhateverHelper module into the controller

[Norm Scherer]

The helpers are more accurately called view helper methods.  They are not intended for use in the controllers.

[Bruno Grasselli]

If you want to use the same methods in both environments (view and controller), you can do like this (in controller):

def method_a

end

def method_b

end

helper_method :method_a, :method_b

Then the methods will be available also in views.

2010/1/1 Norm Scherer <norms...@earthlink.net>

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[Fritz Trapper]

Thanks for your replies.

Now I read the API reference of ActionController::Helpers::ClassMethods
and took a look into my ApplicationController, which has been generated
via RadRails:

class ApplicationController < ActionController::Base
helper :all # include all helpers, all the time

protect_from_forgery
end

If I understand the doc, helper :all should do the job for all
controllers.

To verify this, I set a debugger call as first statement in my crashing
controller and give

y ActionController::Base.helpers_dir

into the debugger. The response is:

NoMethodError Exception: undefined method `helpers_dir' for
ActionController::Base:Class

So what is going wrong there?

[pharrington]

As I said: ActionController::Base.helper does not actually include
helper modules into the controller; it makes them accessible in the
view. You'll need to

include ApplicationHelper # or whatever appropriate module

to have the methods accessible in the controller.

[Fritz Trapper]

pharrington wrote:
> As I said: ActionController::Base.helper does not actually include
> helper modules into the controller; it makes them accessible in the
> view. You'll need to
>
> include ApplicationHelper # or whatever appropriate module
>
> to have the methods accessible in the controller.

In deed, that helps. Sorry for my ignorance.

[Fritz Trapper]

But there is still one annoying point:

My controllers worked using methods from ApplicationHelper until
yesterday morning, when I tried to modify routes.rb and run sume rake
jobs from RadRails that I didn't really understand, including rake
rails:update

The changes in routes.rb have been rolled back, but that didn't help

[pharrington]

On Jan 2, 10:15 am, Fritz Trapper <li...@ruby-forum.com> wrote:
> rake rails:update

Then perhaps helper() actually included the helper modules into the
controller in an earlier version of Rails. Its hard for me to remember
at this point, but I know since at least 2.2 helper()'s behaved as it
does now.

Just curious now; what version of Rails did you have previously
installed, and what version did you upgrade to before running rake
rails:update?

[Fritz Trapper]

pharrington wrote:
> Just curious now; what version of Rails did you have previously
> installed, and what version did you upgrade to before running rake
> rails:update?

I initially installed ruby and rails using synaptic on Ubuntu 9.04. It
was ruby 1.8 and rails 2.1.0-6.

[Fritz Trapper]

One more issue.

class ZaehlersController < ApplicationController
def index
if keineZaehlerVorhanden
blah
end

respond_to do |format|
format.html # index.html.erb
format.xml { render :xml => @zaehlers }
end
end

if !keineZaehlerVorhanden
verify :session => :user_name,
:add_flash => {:error => "error"},
:redirect_to => {:controller => "authentication", :action =>
"login"}
end
end

If it gets called,

if !keineZaehlerVorhanden
veriy...
end

fails with "NameError (undefined local variable or method
`keineZaehlerVorhanden' for ZaehlersController:Class):

After removing the condition around the verify, the index action
terminates successfully - including the

if keineZaehlerVorhanden
blah
end

Why this?

[Fritz Trapper]

I forgot to say: keineZaehlerVorhanden is defined in ApplicationHelper,
which is included in ApplicationController.

[pharrington]

On Jan 2, 11:19 am, Fritz Trapper <li...@ruby-forum.com> wrote:
> One more issue.
>
> class ZaehlersController < ApplicationController
>   def index
>     if keineZaehlerVorhanden
>        blah
>     end
>
>     respond_to do |format|
>       format.html # index.html.erb
>       format.xml  { render :xml => @zaehlers }
>     end
>   end

Look at this carefully. You're closing the respond_to block, and then
closing the index method. keineZaehlerVorhanden isn't a class method,
so of course the error will be thrown.

the error message "fails with "NameError (undefined local variable or
method
`keineZaehlerVorhanden' for **ZaehlersController:Class**)" gives a
prettttttttyyy good clue as to whats going on.

[Fritz Trapper]

pharrington wrote:
> On Jan 2, 11:19�am, Fritz Trapper <li...@ruby-forum.com> wrote:

>> � � � format.xml �{ render :xml => @zaehlers }

>> � � end
>> � end
>
> Look at this carefully. You're closing the respond_to block, and then
> closing the index method. keineZaehlerVorhanden isn't a class method,
> so of course the error will be thrown.

keineZaehlerVorhanden is a method of ApplicationController and it works
inside the index action.

The verify statement is written usually at class level. Right? My idea
was, only to verfy, if the method keineZaehlerVorhanden fails.

The interesting story is, that the construct around the verify worked
fine until I accidentally run a rake rails:update

Seems, that the updated rails version changed something in the handling
of controllers.

My question: How to implement a verification, that should not be
executed under a certain condition?

(Background:
The action should be executable for anybody, as long as no users are
added to the data base - aka installation phase of my app.)

[pharrington]

On Jan 2, 12:32 pm, Fritz Trapper <li...@ruby-forum.com> wrote:
> pharrington wrote:
> > On Jan 2, 11:19 am, Fritz Trapper <li...@ruby-forum.com> wrote:
> >> format.xml { render :xml => @zaehlers }
> >> end
> >> end
>
> > Look at this carefully. You're closing the respond_to block, and then
> > closing the index method. keineZaehlerVorhanden isn't a class method,
> > so of course the error will be thrown.
>
> keineZaehlerVorhanden is a method of ApplicationController and it works
> inside the index action.
>
> The verify statement is written usually at class level. Right? My idea
> was, only to verfy, if the method keineZaehlerVorhanden fails.
>
> The interesting story is, that the construct around the verify worked
> fine until I accidentally run a rake rails:update
>
> Seems, that the updated rails version changed something in the handling
> of controllers.
>
> My question: How to implement a verification, that should not be
> executed under a certain condition?
>

Well now, verify only exists to prevent actions from even being
*invoked* unless certain conditions of the request are met. If you
need tighter control, to filter based on more than just the request,
just use a before_filter. Either way, you should probably focus on
*precisely* what you're trying to accomplish, and the solution will
probably be obvious (and definitely simpler than doing the same check
in two different places).

> (Background:
> The action should be executable for anybody, as long as no users are
> added to the data base - aka installation phase of my app.)
> --
> Posted viahttp://www.ruby-forum.com/.

OK yeah, this is before_filter material. Don't know if the lack of
users in the DB appropriately denotes the "installation phase," but
thats for you to think about.

[Fritz Trapper]

Thanks, now it works as expected.