NAME

XML::Easy::Element - abstract form of XML data element

SYNOPSIS

use XML::Easy::Element;

$element = XML::Easy::Element->new("a",
		{ href => "#there" }, [ "there" ]);

$type_name = $element->type_name;
$attributes = $element->attributes;
$href = $element->attribute("href");
$content = $element->content;

DESCRIPTION

An object of this class represents an XML element, a node in the tree making up an XML document. This is in an abstract form, completely isolated from the textual representation of XML, holding only the meaningful content of the element. This is a suitable form for application code to manipulate an XML representation of application data.

The properties of an XML element are of three kinds. Firstly, the element has exactly one type, which is referred to by a name. Secondly, the element has a set of zero or more attributes. Each attribute consists of a name, which is unique among the attributes of the element, and a value, which is a string of characters. Finally, the element has content, which is a sequence of zero or more characters and (recursively) elements, interspersed in any fashion.

The element type name and attribute names all follow the XML syntax for names. This allows the use of a wide set of Unicode characters, with some restrictions. Attribute values and character content can use almost all Unicode characters, with only a few characters (such as most of the ASCII control characters) prohibited by the specification from being directly represented in XML.

An abstract element object cannot be modified. Once created, its properties are fixed. Tasks that you might think of as "modifying an XML node" actually involve creating a new node.

This class is not meant to be subclassed. XML elements are unextendable, dumb data.

CONSTRUCTOR

XML::Easy::Element->new(TYPE_NAME, ATTRIBUTES, CONTENT)

Constructs and returns a new element object with the specified properties. TYPE_NAME must be a string, ATTRIBUTES must be a reference to a hash, and CONTENT must be a reference to an array, each being in the same form that is returned by the accessor methods (below). Particularly note the constraints for the content array, which must alternate string and element members. All are checked for validity, against the XML 1.0 specification, and the function dies if any are invalid.

METHODS

$element->type_name

Returns the element type name, as a string.

$element->attributes

Returns a reference to a hash encapsulating the element's attributes. In the hash, each key is an attribute name, and the corresponding value is the attribute's value as a string.

$element->attribute(NAME)

Looks up a specific attribute of the element, by a name supplied as a string. If there is an attribute by that name then its value is returned, as a string. If there is no such attribute then undef is returned.

$element->content

Returns a reference to an array encapsulating the element's content. The array has an odd number of members. The first and last elements, and all elements in between with an even index, are strings giving the element's character data. Each element with an odd index is a reference to an element object, being an element contained directly within the present element. Any of the strings may be empty, if the element has no character data between subelements or at the start or end of the content.

SEE ALSO

XML::Easy

AUTHOR

Andrew Main (Zefram) <zefram@fysh.org>

COPYRIGHT

Copyright (C) 2008 PhotoBox Ltd

LICENSE

This module is free software; you can redistribute it and/or modify it under the same terms as Perl itself.