From: Phillip Oertel <me@...>
Date: 2008-07-20T10:03:36+09:00
Subject: Re: XML parser

hi,

you may enjoy reading this!
http://www.rubyinside.com/ruby-xml-crisis-over-libxml-0-8-0-released-955.html
(posted two days ago)

kind regards,
phillip

---

Am 20.07.2008 um 02:34 schrieb Phlip:

> Cédric H. wrote:
>
>> I'm looking for some information about the xml libraries available in
>> Ruby.
>> I've read a few blog post about the pro's and con's of REXML and
>> Libxml but I still have some questions :
>> - as I understand it REXML is part of ruby standard library and so is
>> included in ruby distribution ?
>
> Yes. It's also widely acknowledged as very slow. The RE stands for  
> Regular Expressions, which are only fast when used carefully. Basing  
> an entire parser on them tends to abuse them.
>
> This blog show how to spot-check compliance issues in the three  
> leading Ruby XML parsers:
>
> http://www.oreillynet.com/onlamp/blog/2007/08/assert_hpricot_1.html
>
>> - libxml is a wrapper for gnome libxml and must be installed and
>> compiled with gem ?
>
> Ordinarily, that process would be mostly harmless. You may already  
> have libxml2-dev, if you have a GNU platform such as Ubuntu or CygWin.
>
> However, the current libxml-ruby has a nasty bug. First, it sprays  
> lots of
>
>  No definition for ruby_xml_parser_context_options_get
>
> into the console. Then it refuses to install the libxml_so.so file  
> that it just created. I don't know this bug's status, but because my  
> assert_xpath works best with libxml, I must overcome it whenever we  
> build a new workstation at work! Sometimes I must manually copy its  
> executables into Ruby's paths...
>
> (Our production code does not use libxml - only the test code.)
>
> I just tried to install while writing this post, and 0.8.1 might  
> have worked on Ubuntu.
>
>> - is libxml really a full validating and compliant parser ?
>
> I suspect it's the reference implementation for XML. It certainly  
> takes every DOCTYPE and schema very seriously!
>
> Better, it actually forgives some errors and keeps working, unlike  
> REXML
>
>> - how do you use xslt in Ruby ? do you use http://raa.ruby-lang.org/project/ruby-xslt/
>> or http://rubyforge.org/projects/libxsl/ (if I'm right the second one
>> is part of libxml ? )
>> As you see I'm lost and I would really appreciate your help or some
>> comprehensive post about xml processing in ruby .
>
> Sorry! I was knocking 'em down, and you lost me at XSLT.
>
> In a pinch, I would pipe text thru xsltproc, and not worry about  
> deep language integration. XSLT is nothing but a big filter, so I  
> thought you could use it without making an object out of it.
>
> -- 
>  Phlip
>