From: Robert Klemme <shortcutter@...>
Date: 2012-08-28T20:10:37+09:00
Subject: Re: nokogiri xpath query with text containing "&amp;"

On Tue, Aug 28, 2012 at 1:04 PM, Mert <lists@ruby-forum.com> wrote:
> Hi all,
>
> I am trying to run some xpath queries on a XML file. But it seems
> nokogiri can not handle texts containing &amp; values.

That's not true.  The issue is with your understanding (or lack
thereof) of XML Entities.  See below.

> here is an example, second line prints nothing. if i change &amp; to
> something else in both xml and xpath expression, i get the values i
> expect.
>
> How can i query xpath expressions with XML excapes.
>
> file_xml = Nokogiri::XML File.open(file_configurable)
> print
> file_xml.xpath("//Match[text()='value1&amp;value2']/../Value").text.to_s

We would need to see your input but I guess it's something like this:

irb(main):001:0> xml = "<a>foo&amp;bar</a>"
=> "<a>foo&amp;bar</a>"
irb(main):002:0> dom = Nokogiri.XML(xml)
=> #<Nokogiri::XML::Document:0x..fc0107cf6 name="document"
children=[#<Nokogiri::XML::Element:0x..fc0107b34 name="a"
children=[#<Nokogiri::XML::Text:0x..fc010795e "foo&bar">]>]>
irb(main):003:0> dom.xpath '//a[text()="foo&bar"]'
=> [#<Nokogiri::XML::Element:0x..fc0107b34 name="a"
children=[#<Nokogiri::XML::Text:0x..fc010795e "foo&bar">]>]

You tried

irb(main):004:0> dom.xpath '//a[text()="foo&amp;bar"]'
=> []

That does not work because the "&amp;" only exists in the external
representation of the XML (the file).  The XML Entity is parsed and
the document contains the literal "&":

irb(main):005:0> dom.root.text.to_s
=> "foo&bar"
irb(main):006:0> dom.root.text
=> "foo&bar"

Kind regards

robert


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