Rails - Nov 2005 - Defining a variable in the environment and using it in controllers and views

Hi,

I wanted to define a global variable in environment.rb like this:

@pagemeta = {:title       => ''Default page title'',
             :description => ''Default page description'',
             :keywords    => ''Default page keywords''}

And then, in a controller, override one or several of its values (like 
@pagemeta[:title] = ''some title''), and use it in the views:

<title><%= @pagemeta[:title] %></title>

But Rails throws an error, apparently because it cannot access the 
@pagemeta variable inside the controller/view... How can I accomplish 
what I''m trying to do?

Thanks in advance!

Ivan V.

i.v.r. wrote:
> Hi,
> 
> I wanted to define a global variable in environment.rb like this:
> 
> @pagemeta = {:title       => ''Default page title'',
>             :description => ''Default page
description'',
>             :keywords    => ''Default page keywords''}
> 
> And then, in a controller, override one or several of its values (like 
> @pagemeta[:title] = ''some title''), and use it in the
views:
> 
> <title><%= @pagemeta[:title] %></title>
> 
> But Rails throws an error, apparently because it cannot access the 
> @pagemeta variable inside the controller/view... How can I accomplish 
> what I''m trying to do?
> 
> Thanks in advance!
> 
> Ivan V.
> 
> _______________________________________________
> Rails mailing list
> Rails-1W37MKcQCpIf0INCOvqR/iCwEArCW2h5@public.gmane.org
> http://lists.rubyonrails.org/mailman/listinfo/rails
I, too, am confused by how the environment files work exactly.  I''ve
looked
over pp 187-188, and 461-463, but I still don''t understand how an entry
you add
to one of the environment files becomes accessible to you in, say, a 
controller, or even what an entry should look like.

Tips please?

Regards,

Dan

Daniel Berger wrote:
> i.v.r. wrote:
>> Hi,
>>
>> I wanted to define a global variable in environment.rb like this:
>>
>> @pagemeta = {:title       => ''Default page title'',
>>             :description => ''Default page
description'',
>>             :keywords    => ''Default page
keywords''}
>>
>> And then, in a controller, override one or several of its values 
>> (like @pagemeta[:title] = ''some title''), and use it
in the views:
>>
>> <title><%= @pagemeta[:title] %></title>
>>
>> But Rails throws an error, apparently because it cannot access the 
>> @pagemeta variable inside the controller/view... How can I accomplish 
>> what I''m trying to do?
>>
>> Thanks in advance!
>>
>> Ivan V.
>>
>> _______________________________________________
>> Rails mailing list
>> Rails-1W37MKcQCpIf0INCOvqR/iCwEArCW2h5@public.gmane.org
>> http://lists.rubyonrails.org/mailman/listinfo/rails
>
> I, too, am confused by how the environment files work exactly. 
I''ve
> looked over pp 187-188, and 461-463, but I still don''t understand
how
> an entry you add to one of the environment files becomes accessible to 
> you in, say, a controller, or even what an entry should look like.
>
> Tips please?
>
> Regards,
>
> Dan
> _______________________________________________
> Rails mailing list
> Rails-1W37MKcQCpIf0INCOvqR/iCwEArCW2h5@public.gmane.org
> http://lists.rubyonrails.org/mailman/listinfo/rails
>
Hi,

I solved it using a module/class combination. In my environment.rb 
(actually on another file loaded by environment.rb, but it doesn''t 
really matter), I have this:

module MyModule
  class PageMeta
    attr_writer :title, :description, :keywords
    attr_reader :title, :description, :keywords
    def initialize(title, description, keywords)
      @title       = title
      @description = description
      @keywords    = keywords
    end
end
 
  $pagemeta = PageMeta.new(''default title'', ''default
description'',
''some, keywords'')
end

And then in my controllers I have (for example):

class WelcomeController < ApplicationController
    def index
        $pagemeta.title = ''overriding title''
    end
end

And in a view I use:

<title><%= $pagemeta.title %></title>

It seems global variables (prefixed by the ''$'' sign)
aren''t really the
Ruby way, but I couldn''t find an easier alternative...

Hope that helps.

Ivan V.

On Nov 16, 2005, at 8:30 AM, Daniel Berger wrote:
> i.v.r. wrote:
>> Hi,
>> I wanted to define a global variable in environment.rb like this:
>> @pagemeta = {:title       => ''Default page title'',
>>             :description => ''Default page
description'',
>>             :keywords    => ''Default page
keywords''}
>> And then, in a controller, override one or several of its values  
>> (like @pagemeta[:title] = ''some title''), and use it
in the views:
>> <title><%= @pagemeta[:title] %></title>
>> But Rails throws an error, apparently because it cannot access the  
>> @pagemeta variable inside the controller/view... How can I  
>> accomplish what I''m trying to do?
>> Thanks in advance!
>> Ivan V.
>> _______________________________________________
>> Rails mailing list
>> Rails-1W37MKcQCpIf0INCOvqR/iCwEArCW2h5@public.gmane.org
>> http://lists.rubyonrails.org/mailman/listinfo/rails
>
> I, too, am confused by how the environment files work exactly.   
> I''ve looked over pp 187-188, and 461-463, but I still
don''t
> understand how an entry you add to one of the environment files  
> becomes accessible to you in, say, a controller, or even what an  
> entry should look like.
>
> Tips please?
>
> Regards,
>
> Dan

Guys-

	You can''t use a @pagemeta variable like that without an object that  
contains it or something. Your best bet would be to use a constant  
for that instead. Then it will be automatically available everywhere  
in your app:

  PAGE_META = {:title       => ''Default page title'',
       :description => ''Default page description'',
       :keywords    => ''Default page keywords''}


HTH-

-Ezra Zygmuntowicz
Yakima Herald-Republic
WebMaster
http://yakimaherald.com
509-577-7732
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