XPath Perl get attribute value_问答_开发者_运维开发者技术经验分享

开发者 https://www.devze.com 2023-01-11 22:27 出处：网络

I\'m trying to get XPath to return an attribute value yet first search for the tag\'s contents, i.e. if I have

I'm trying to get XPath to return an attribute value yet first search for the tag's contents, i.e. if I have

<select name="xxx">
  <option=bla>123</option>
  <option=blubb>456</option>
</select>

I want to say, "search for the option tag containing 456 within a certain select tag with name "xxx".

I do this:

my $xp = XML::XPath开发者_运维知识库Engine->new();
my $tree = HTML::TreeBuilder::XPath->new_from_content($mech->content);
my $search = $xp->find('//select[@name="xxx"]/option[.=~ /' . $re . '/]/@value', $tree);

($re is a regexp for the option part.)

All it returns on the last line ($xp->find) is

Can't locate object method "getRootNode" via package "HTML::TreeBuilder::XPath::Attribute" at /usr/lib/perl5/site_perl/5.8.8/XML/XPathEngine/NodeSet.pm line 90, <MYFILE> line 1.

What's wrong here? Is that module faulty? Is my XPath faulty? Should I use something else that "just works"?

PS. I don't use XML::Parser because it complains about a perfectly valid page

mismatched tag at line 9, column 3, byte 427 at /usr/lib/perl5/vendor_perl/5.8.8/i586-linux-thread-multi/XML/Parser.pm line 187


<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
    <title>aaaa</title>
<link href="/x/include/main.css" type="text/css" rel="stylesheet">
<link href="/x/images/favicon.ico" rel="shortcut icon">
<meta http-equiv="Content-Type" content="text/html;charset=utf-8">
<script type="text/javascript" src="/x/include/layout.js"></script>
</head>

<body style=
.....

Well, your example HTML doesn't have any value attributes, and you don't give a complete example script. But the following script works fine for me:

use XML::XPathEngine;
use HTML::TreeBuilder::XPath;

my $content = <<'';
<select name="xxx">
  <option value=bla>123</option>
  <option value=blubb>456</option>
</select>

my $re = '456';

my $xp = XML::XPathEngine->new();
my $tree = HTML::TreeBuilder::XPath->new_from_content($content);
my $search = $xp->find('//select[@name="xxx"]/option[.=~ /' . $re . '/]/@value', $tree);

print "$search\n";

At a guess, you've put something in $re that doesn't work.

I'm using: