From: dblack@...
Date: 2003-01-11T00:47:09+09:00
Subject: Re: REXML and XPath Confusion

Hi --

On Fri, 10 Jan 2003, Mark Probert wrote:

>
> Rubyists,
>
> I am confused!  (Nothing unusual there! :-)
>
> Using XPath.match, I get an array of attributes.  When I try to
> match against this array, with what seems to be the same name,
> it doesn't match.  Any ideas?
>
>
> $ cat test.xml
> <?xml version="1.0"?>
> <doc>
>    <section name="intro">
>    <panel name="overview">   </panel>
>    <panel name="stuff">  </panel>
>    </section>
>    <section name="foo">
>    </section>
>    <section name="bar">
>    </section>
> </doc>
>
> $ cat test.rb
> require "rexml/xpath"
> require "rexml/document"
> include REXML
>
> doc = Document.new File.new( "test.xml" )
>
> panels = XPath.match( doc, "//panel/attribute::name" )
> panels.each { |panel|
>    puts "panel --> [#{panel}]"
> }
> puts "-----"
>
> doc.elements.each("doc/section") { |sect|
>    puts "sect --> #{sect.attributes["name"]}"
>    sect.elements.each("panel") { |panel|
>          name = panel.attributes["name"]
>          puts "panel --> [#{name}]"
>          puts (panels.include?(name)) ? "included" : "not found"
>    }
> }

panels is an array of REXML::Attribute objects.  That array won't
include name, but it will include a panel whose value is the same as
name.  You just have to dig a bit to get the value.

Replace your last line of code with:

  puts panels.detect {|p| p.value == name } ? "included" : "not found"


David

-- 
David Alan Black
home: dblack@candle.superlink.net
work: blackdav@shu.edu
Web:  http://pirate.shu.edu/~blackdav