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XML::DOM::Parser

NAME

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

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 the XML::Parser manpage

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 the XML::Parser manpage 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 the XML::DOM::Document manpage 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 the LWP::UserAgent manpage 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.