Rails - May 2006 - access to an ApplicationController property from a view

Hi there,

How is it possible to get access to an ApplicationController property 
from a view?

Consider this (simplified) situation:

class ApplicationController < ActionController::Base
   def folder_id
     @folder_id = params[:id]
     return @folder_id
   end
end

class FolderController < ApplicationController
   def show
     @folder = Folder.find_by_id(folder_id)
   end
end

So far, so good, BUT... when trying to access folder_id in the show-view 
like this <%= folder_id %>, I get an error (undefined local variable or 
method `folder_id''). Is this possible or do I NEED to use instance 
variables -- which I''d rather not do?

Thanks.

Mischa.

-- 
Open source file management webapp :: Boxroom :: 
http://boxroom.rubyforge.org/

Hi Mischa,

Mischa Berger wrote:
> So far, so good, BUT... when trying to access folder_id in the show-view 
> like this <%= folder_id %>, I get an error (undefined local variable
or
> method `folder_id''). Is this possible or do I NEED to use instance
> variables -- which I''d rather not do?
You''ll need to use instance variables.  By definition, the scope of a
local
variable is the block within which it''s declared.  A local variable
declared
in a controller action method only has meaning within that action method. 
Not only is it not available in a view, it''s not available in any of
the
other action methods in the controller.

Just as a point of information, what''s your issue with using instance 
variables?

Best regards,
Bill

> You''ll need to use instance variables.  By definition, the scope
of a
> local variable is the block within which it''s declared.  A local 
> variable declared in a controller action method only has meaning within 
> that action method. Not only is it not available in a view, it''s
not
> available in any of the other action methods in the controller.
Yeah, but I''m not trying to use a local variable, I''m trying
to access
the method folder_id which returns @folder_id.

Why IS it possible to use params[:id] instead of @params[:id] in a view 
and why ISN''T it possible to use folder_id instead of @folder_id like 
I''m trying to do in my example?
> Just as a point of information, what''s your issue with using
instance
> variables?
I''m trying to encapsulate @folder_id. The view only has to know about 
folder_id. In the method I can set @folder_id to different values 
according to the situation and return the appropriate value.
> Best regards,
> Bill
Thanks again.

On Thu, May 18, 2006 at 10:11:29PM +0200, Mischa Berger wrote:
} Hi there,
} 
} How is it possible to get access to an ApplicationController property 
} from a view?
} 
} Consider this (simplified) situation:
} 
} class ApplicationController < ActionController::Base
}   def folder_id
}     @folder_id = params[:id]
}     return @folder_id
}   end
} end
} 
} class FolderController < ApplicationController
}   def show
}     @folder = Folder.find_by_id(folder_id)
}   end
} end
} 
} So far, so good, BUT... when trying to access folder_id in the show-view 
} like this <%= folder_id %>, I get an error (undefined local variable or 
} method `folder_id''). Is this possible or do I NEED to use instance 
} variables -- which I''d rather not do?

<%= controller.folder_id %>

} Thanks.
} Mischa.
--Greg