NAME
XML::Easy::Element - abstract form of XML element
SYNOPSIS
use XML::Easy::Element;
$element = XML::Easy::Element->new("a",
{ href => "#there" }, $content);
$type_name = $element->type_name;
$attributes = $element->attributes;
$href = $element->attribute("href");
$content = $element->content_object;
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. Element objects are better processed using the functions in XML::Easy::NodeBasics than using the methods of this class.
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 in the same form that is returned by the accessor method
attributes
(below). CONTENT must be a reference to either an XML::Easy::Content object or an array of the type that can be passed to that class'snew
constructor. All are checked for validity, against the XML 1.0 specification, and the functiondie
s 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. The supplied NAME must be a string containing a valid attribute name. 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_object
-
Returns a reference to an XML::Easy::Content object encapsulating the element's content.
- $element->content
-
Returns a reference to an array listing the element's content in the canonical form that is returned by the
content
accessor of XML::Easy::Content.
SEE ALSO
XML::Easy::Content, XML::Easy::NodeBasics
AUTHOR
Andrew Main (Zefram) <zefram@fysh.org>
COPYRIGHT
Copyright (C) 2008 PhotoBox Ltd
Copyright (C) 2009 Andrew Main (Zefram) <zefram@fysh.org>
LICENSE
This module is free software; you can redistribute it and/or modify it under the same terms as Perl itself.