Element - A module that captures the values of a typical XML element, including references to parents, children, attributes, namespaces, and all enclosing information.
The purpose of this module is to mimic the behavior of the GGF's NM-WG parsing elements found in the java implementation of perfSONAR. Although the java version consists of a single specialized element for each known XML element, this class presents a generic 'element' structure that can be configured in any possible way.
use Element;
# consder that we wish to make this XML:
#
# <nmwg:store xmlns:nmwg="http://ggf.org/ns/nmwg/base/2.0/">
# <nmwg:metadata id="m1">
# <netutil:subject xmlns:netutil="http://ggf.org/ns/nmwg/characteristic/utilization/2.0/" id="s1">
# <nmwg:eventType>snmp.1.3.6.1.2.1.2.2.1.10</nmwg:eventType>
# </nmwg:metadata>
# <nmwg:data id="d1" metadataIdRef="m1" />
# </nmwg:store>
my $store = new Element();
$store->setLocalName("store");
$store->setPrefix("nmwg");
$store->setURI("http://ggf.org/ns/nmwg/base/2.0/");
$store->setQName($store->getPrefix().":".$store->getLocalName());
$store->addAttribute("xmlns:nmwg","http://ggf.org/ns/nmwg/base/2.0/");
my $md = new Element();
$md->setLocalName("metadata");
$md->setPrefix("nmwg");
$md->setURI("http://ggf.org/ns/nmwg/base/2.0/");
$md->setQName($md->getPrefix().":".$md->getLocalName());
$md->setID("m1");
$md->addAttribute("id","m1");
my $subject = new Element();
$subject->setLocalName("subject");
$subject->setPrefix("netutil");
$subject->setURI("http://ggf.org/ns/nmwg/characteristic/utilization/2.0/");
$subject->setQName($subject->getPrefix().":".$subject->getLocalName());
$subject->addAttribute("xmlns:netutil","http://ggf.org/ns/nmwg/characteristic/utilization/2.0/");
$subject->setID("s1");
$subject->addAttribute("id","s1");
my $event = new Element();
$event->setLocalName("eventType");
$event->setPrefix("nmwg");
$event->setURI("http://ggf.org/ns/nmwg/base/2.0/");
$event->setQName($event->getPrefix().":".$event->getLocalName());
$event->setValue("snmp.1.3.6.1.2.1.2.2.1.10");
my $d = new Element();
$d->setLocalName("data");
$d->setPrefix("nmwg");
$d->setURI("http://ggf.org/ns/nmwg/base/2.0/");
$d->setQName($d->getPrefix().":".$d->getLocalName());
$d->setID("d1");
$d->addAttribute("id","d1");
$d->addAttribute("metadataIdRef","m1");
$md->addChild($subject);
$md->addChild($event);
$store->addChild($md);
$store->addChild($d);
$store->print();
This object is depened upon the XML::SAX parser, as well as our custom handler to populate an object tree from an XML instance. It is possible to build XML instances through a series of API calls as well.
There are many get/set methods, as well as the ability to output an element (and childrent) into readable XML.
Creates a new object, does not support the passing of any initial values.
The parent is the element that directly encloses a particular element. This method allows a reference to be set so the parent can be easily tracked.
Returns the value of the parent element.
If an element contains an attribute for 'id', it is set here. Otherwise a randomly genereated number will be used.
Returns the id value of an element.
Sets the 'prefix', a shortcut that maps a string to the namespace URI for an element.
Returns the prefix of an element.
Sets the URI of the namespace for an element.
Returns the namespace URI of an element.
Sets the local (non namespace tied) name of an element.
Returns the local (non-prefixed) name of an element.
Sets the qualified (prefixed to a namespace) name of an element.
Returns the qualified (prefixed) name of an element.
Sets the text value of an element.
Returns the text value of an element.
Adds the element 'child' to the child array of an element.
Returns the 'first' child element that matches the supplied name.
Returns the child element that matches the supplied id.
Returns the child element for a particular 'index' value in the child element array.
Adds an attribute/value pair to an element.
Returns the value of an attribute that matches the supplied name.
Prints the XML output for a element and all of it's children. This module is overloaded to support the standard perl print.
Given a numeric value, prints spaces equal to this value to 'pretty print' the XML output.
To join the 'perfSONAR-PS' mailing list, please visit:
https://mail.internet2.edu/wws/info/i2-perfsonar
The perfSONAR-PS subversion repository is located at:
https://svn.internet2.edu/svn/perfSONAR-PS
Questions and comments can be directed to the author, or the mailing list.
Jason Zurawski, <zurawski@eecis.udel.edu>
Copyright (C) 2007 by Jason Zurawski
This library is free software; you can redistribute it and/or modify it under the same terms as Perl itself, either Perl version 5.8.8 or, at your option, any later version of Perl 5 you may have available.
