# Libxml: uninitialized constant

**URL:** <https://www.ruby-forum.com/t/libxml-uninitialized-constant/191635>\
**Category:** Rails\
**Created:** [July 15, 2010, 5:26pm UTC](https://www.ruby-forum.com/t/libxml-uninitialized-constant/191635 "2010-07-15T17:26:03Z")\
**Posts on this page:** 2\
**Page:** 1

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**Author:** ![avsej](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/a/f07891/32.png) [@avsej](https://www.ruby-forum.com/u/avsej)\
**Post date:** [July 15, 2010, 5:26pm UTC](https://www.ruby-forum.com/t/libxml-uninitialized-constant/191635/1 "2010-07-15T17:26:03Z")

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Hi all!

I try to use libxml-ruby with my ROR-application and get the following  
error message: “uninitialized constant AdminController::XML”.

From controller file:

require ‘rubygems’  
require ‘xml/libxml’  
…  
parser = XML::Parser.new

And the same code in irb work correctly:

irb(main):001:0\> require ‘rubygems’  
=\> true  
irb(main):002:0\> require ‘xml/libxml’  
=\> true  
irb(main):003:0\> parser = XML::Parser.new  
=\> #XML::Parser:0x7fc460cf11c0

Why it doesn’t work in Rails?

(Rails 3.0.0.beta4, libxml-ruby-1.1.4)

---

<div class="post-metadata">

**Author:** ![avsej](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/a/f07891/32.png) [@avsej](https://www.ruby-forum.com/u/avsej)\
**Post date:** [July 15, 2010, 7:20pm UTC](https://www.ruby-forum.com/t/libxml-uninitialized-constant/191635/2 "2010-07-15T19:20:48Z")

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Fix problem. It was necessary to add in Gemfile string “gem ‘libxml-  
ruby’”.