How to access one variable across the page in ruby?

Question

Now I am new in ruby language. Currently learning ruby. I am expert coder in the PHP. Basically I am working in the CakePHP. CakePHP and Ruby directory structure approximately same. But I am confusing little bit in the Ruby Code.

In CakePHP while I am define any variable in bootstrap.php I am getting this variable across the site.

Suppose I have a variable name $gallery_path = 'files/gallery/'; If I echo $gallery_path in controller, model and view. I am getting my gallery path.

But here in ruby I am unable to define any variable like php bootstrap.php Please suggest me.

What sort of variables are you trying to define? Ruby strongly encourages people to organize these into modules or classes to simplify access and keep them from conflicting. — tadman, Apr 25 '16 at 08:00
what Chinu is talking about in PHP is called global variable. So his question is : How can I use the global variable feature from PHP in Ruby... — Martin Verjans, Apr 25 '16 at 08:51
Possible duplicate of [Ruby on Rails: Where to define global constants?](http://stackoverflow.com/questions/4110866/ruby-on-rails-where-to-define-global-constants) — Holger Just, Apr 25 '16 at 10:35

score 2 · Answer 1 · answered Apr 25 '16 at 08:04

2

For things that change frequently enough that you need to edit them now and then, but infrequently enough that you're not constantly changing it, a simple module works well here.

You can start with something like this:

module SiteConfiguration
  mattr_accessor :site_name
  mattr_accessor :payment_provider
end

Then you can configure that in config/environment.rb:

SiteConfiguration.site_name = 'The Site'
SiteConfiguration.payment_provider = 'PayPal'

These are accessible everywhere in your app.

answered Apr 25 '16 at 08:04

tadman

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Can you please say me about the `module Siteconfiguration`? – Chinmay235 May 20 '16 at 07:20
I am getting error message `uninitialized constant ApplicationController::SiteConfiguration` – Chinmay235 May 20 '16 at 07:52
@Chinu You need to put `site_configuration.rb` somewhere that's auto-loaded. `app/concerns` is one place that's usually checked. – tadman May 20 '16 at 09:33
Ok. Let me know how to get site name in my layout? – Chinmay235 May 20 '16 at 10:03
It's just as you would with anything: `<%= SiteConfiguration.site_name %>`. – tadman May 20 '16 at 15:52
can you please briefly describe me. I am tried but unable to do that. – Chinmay235 May 31 '16 at 10:51
Here I am using using this `config/site_configuration.rb` I am putting this code `module SiteConfiguration mattr_accessor :site_name mattr_accessor :payment_provider end` and `config/environment.rb` putting `SiteConfiguration.site_name = 'The Site' SiteConfiguration.payment_provider = 'PayPal'` let me know is it right or not? – Chinmay235 May 31 '16 at 10:57
I am getting error message `uninitialized constant ActionView::CompiledTemplates::SiteConfiguration` – Chinmay235 May 31 '16 at 11:01
Finally i got my output. Thank you – Chinmay235 May 31 '16 at 11:30
I faced another problem `no implicit conversion of nil into String` – Chinmay235 Jun 01 '16 at 07:54
While I am getting `no implicit conversion of nil into String` message I restated my server then working fine. After some times I am getting same error. I mean each time I am restarting my server. – Chinmay235 Jun 01 '16 at 07:55
I have added one question. Please check http://stackoverflow.com/questions/37564295/how-to-fix-no-implicit-conversion-of-nil-into-string-in-ruby – Chinmay235 Jun 01 '16 at 09:28

score 0 · Answer 2 · answered Apr 25 '16 at 07:30

0

you can use environment variables, try this gem: https://github.com/bkeepers/dotenv or you can define them:

ENV["host"] = "localhost:3000"

answered Apr 25 '16 at 07:30

Artem Biserov

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Sherlock_Stalker · Answer 3 · 2016-04-25T09:18:33.903

0

I think you mean global variables. In Ruby-on-Rails you can write it like

Controller:

@value = 2+1

HTML:

<%= @value %>

So your output in your browser will be "3"

edited Apr 25 '16 at 09:18

answered Apr 25 '16 at 07:58

Sherlock_Stalker

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9

score 0 · Answer 4 · answered Apr 25 '16 at 08:15

0

Your application_controller.rb should be write below

$gallery_path = 'files/gallery/';

Your view file

<%=$gallery_path %>

answered Apr 25 '16 at 08:15

Developer

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This is extremely messy and should be an absolute last resort. Global variables are used very, very sparingly in Ruby. – tadman Apr 25 '16 at 09:03

How to access one variable across the page in ruby?

4 Answers4