Forum: Ruby how to require specific version of gem in my project

Hi All,

I have installed two different versions of a gem (1.0.0 and 1.0.4)


My code :

===============================

require 'test' , '>= 1.3.6'


===============================

it gives me an error

rake aborted!
uninitialized constant Test


but i already installed this version of gem


Can any one help me ......

On Dec 5, 2012, at 01:27 , Mallikarjuna Yaddala <lists@ruby-forum.com> 
wrote:

> Hi All,
>
> I have installed two different versions of a gem (1.0.0 and 1.0.4)
>
>
> My code :
>
> ===============================
>
> require 'test' , '>= 1.3.6'

require doesn't take 2 args (as it doesn't makes sense to be able to 
require across 2+ versions of the same gem). From the rdoc:

  % ri require
  ...
  === Implementation from Kernel
  ------------------------------------------------------------------------------
    require(string)    => true or false
  ...

You want to specify that at the gem level using #gem:

  % ri gem
  ...
  (from gem rubygems-1.8.24)
  === Implementation from Kernel
  ------------------------------------------------------------------------------
    gem(gem_name, *requirements)
  ...

So you want:

  gem "test", ">= 1.3.6" # assuming the gem name is actually "test"
  require "test"         # assuming there is a file "test.rb" in the gem

BUT... also note that your version specifier above will NOT match either 
version you have installed.

Ryan Davis wrote in post #1087894:
> On Dec 5, 2012, at 01:27 , Mallikarjuna Yaddala <lists@ruby-forum.com>
> wrote:
>
>> Hi All,
>>
>> I have installed two different versions of a gem (1.0.0 and 1.0.4)
>>
>>
>> My code :
>>
>> ===============================
>>
>> require 'test' , '>= 1.3.6'
>
> require doesn't take 2 args (as it doesn't makes sense to be able to
> require across 2+ versions of the same gem). From the rdoc:
>
>   % ri require
>   ...
>   === Implementation from Kernel
>   ------------------------------------------------------------------------------
>     require(string)    => true or false
>   ...
>
> You want to specify that at the gem level using #gem:
>
>   % ri gem
>   ...
>   (from gem rubygems-1.8.24)
>   === Implementation from Kernel
>   ------------------------------------------------------------------------------
>     gem(gem_name, *requirements)
>   ...
>
> So you want:
>
>   gem "test", ">= 1.3.6" # assuming the gem name is actually "test"
>   require "test"         # assuming there is a file "test.rb" in the gem
>
> BUT... also note that your version specifier above will NOT match either
> version you have installed.


where i need to add these lines

gem "test", ">= 1.3.6"
require "test"

in rakefile or Gemfile ?