perldoc > XML::DOM::Parser

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📖 NAME

XML::DOM::Parser — An XML::Parser that builds XML::DOM document structures

🚀 Quick Reference

Use Case	Command	Description
🔍 Parse XML file	XML::DOM::Parser->new->parsefile("file.xml")	Parse an XML file and return a Document object
🔍 Parse XML string	XML::DOM::Parser->new->parse($xml_string)	Parse an XML string and return a Document object
🌐 Parse URL	XML::DOM::Parser->new->parsefile("http://...")	Download and parse XML from a URL using LWP
⚙️ Custom LWP agent	XML::DOM::Parser::set_LWP_UserAgent($agent)	Set global LWP::UserAgent for URL parsing
⚙️ Per‑parser LWP agent	XML::DOM::Parser->new(LWP_UserAgent => $agent)	Pass a custom LWP agent to a specific parser
🧹 Memory cleanup	$doc->dispose	Break circular references to avoid memory leaks
🔁 Keep CDATA	XML::DOM::Parser->new(KeepCDATA => 1)	Store CDATASection nodes instead of converting to Text

📝 SYNOPSIS

 use XML::DOM;

 my $parser = new XML::DOM::Parser;
 my $doc = $parser->parsefile ("file.xml");
 $doc->dispose; # Avoid memory leaks - cleanup circular references

📚 DESCRIPTION

XML::DOM::Parser extends XML::Parser

The XML::Parser module was written by Clark Cooper and is built on top of XML::Parser::Expat, which is a lower level interface to James Clark's expat library.

XML::DOM::Parser parses XML strings or files and builds a data structure that conforms to the API of the Document Object Model as described at http://www.w3.org/TR/REC-DOM-Level-1. See the XML::Parser manpage for other additional properties of the XML::DOM::Parser class. Note that the 'Style' property should not be used (it is set internally.)

The XML::Parser NoExpand option is more or less supported, in that it will generate EntityReference objects whenever an entity reference is encountered in character data. I'm not sure how useful this is. Any comments are welcome.

As described in the synopsis, when you create an XML::DOM::Parser object, the parse and parsefile methods create an XML::DOM::Document object from the specified input. This Document object can then be examined, modified and written back out to a file or converted to a string.

When using XML::DOM with XML::Parser version 2.19 and up, setting the XML::DOM::Parser option KeepCDATA to 1 will store CDATASections in CDATASection nodes, instead of converting them to Text nodes. Subsequent CDATASection nodes will be merged into one. Let me know if this is a problem.

🌐 Using LWP to parse URLs

The parsefile() method now also supports URLs, e.g. http://www.erols.com/enno/xsa.xml. It uses LWP to download the file and then calls parse() on the resulting string. By default it will use a LWP::UserAgent that is created as follows:

 use LWP::UserAgent;
 $LWP_USER_AGENT = LWP::UserAgent->new;
 $LWP_USER_AGENT->env_proxy;

Note that env_proxy reads proxy settings from environment variables, which is what I need to do to get thru our firewall. If you want to use a different LWP::UserAgent, you can either set it globally with:

 XML::DOM::Parser::set_LWP_UserAgent ($my_agent);

or, you can specify it for a specific XML::DOM::Parser by passing it to the constructor:

 my $parser = new XML::DOM::Parser (LWP_UserAgent => $my_agent);

Currently, LWP is used when the filename (passed to parsefile) starts with one of the following URL schemes: http, https, ftp, wais, gopher, or file (followed by a colon.) If I missed one, please let me know.

The LWP modules are part of libwww-perl which is available at CPAN.

📖 NAME 🚀 Quick Reference 📝 SYNOPSIS 📚 DESCRIPTION 🌐 Using LWP to parse URLs