1XML::DOM::Element(3) User Contributed Perl Documentation XML::DOM::Element(3)
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6 XML::DOM::Element - An XML element node in XML::DOM
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9 XML::DOM::Element extends XML::DOM::Node.
10 By far the vast majority of objects (apart from text) that authors
12 encounter when traversing a document are Element nodes. Assume the fol‐
13 lowing XML document:
14 <elementExample id="demo">
16 <subelement1/>
17 <subelement2><subsubelement/></subelement2>
18 </elementExample>
19 When represented using DOM, the top node is an Element node for "ele‐
21 mentExample", which contains two child Element nodes, one for "subele‐
22 ment1" and one for "subelement2". "subelement1" contains no child
23 nodes.
24 Elements may have attributes associated with them; since the Element
26 interface inherits from Node, the generic Node interface method getAt‐
27 tributes may be used to retrieve the set of all attributes for an ele‐
28 ment. There are methods on the Element interface to retrieve either an
29 Attr object by name or an attribute value by name. In XML, where an
30 attribute value may contain entity references, an Attr object should be
31 retrieved to examine the possibly fairly complex sub-tree representing
32 the attribute value. On the other hand, in HTML, where all attributes
33 have simple string values, methods to directly access an attribute
34 value can safely be used as a convenience.
35 METHODS
37 getTagName
39 The name of the element. For example, in:
40 <elementExample id="demo">
42 ...
43 </elementExample>
44 tagName has the value "elementExample". Note that this is case-pre‐
46 serving in XML, as are all of the operations of the DOM.
47 getAttribute (name)
49 Retrieves an attribute value by name.
50 Return Value: The Attr value as a string, or the empty string if
52 that attribute does not have a specified or default value.
53 setAttribute (name, value)
55 Adds a new attribute. If an attribute with that name is already
56 present in the element, its value is changed to be that of the
57 value parameter. This value is a simple string, it is not parsed as
58 it is being set. So any markup (such as syntax to be recognized as
59 an entity reference) is treated as literal text, and needs to be
60 appropriately escaped by the implementation when it is written out.
61 In order to assign an attribute value that contains entity refer‐
62 ences, the user must create an Attr node plus any Text and Enti‐
63 tyReference nodes, build the appropriate subtree, and use setAt‐
64 tributeNode to assign it as the value of an attribute.
65 DOMExceptions:
67 * INVALID_CHARACTER_ERR
69 Raised if the specified name contains an invalid character.
70 * NO_MODIFICATION_ALLOWED_ERR
72 Raised if this node is readonly.
73 removeAttribute (name)
75 Removes an attribute by name. If the removed attribute has a
76 default value it is immediately replaced.
77 DOMExceptions:
79 * NO_MODIFICATION_ALLOWED_ERR
81 Raised if this node is readonly.
82 getAttributeNode
84 Retrieves an Attr node by name.
85 Return Value: The Attr node with the specified attribute name or
87 undef if there is no such attribute.
88 setAttributeNode (attr)
90 Adds a new attribute. If an attribute with that name is already
91 present in the element, it is replaced by the new one.
92 Return Value: If the newAttr attribute replaces an existing
94 attribute with the same name, the previously existing Attr node is
95 returned, otherwise undef is returned.
96 DOMExceptions:
98 * WRONG_DOCUMENT_ERR
100 Raised if newAttr was created from a different document than
101 the one that created the element.
102 * NO_MODIFICATION_ALLOWED_ERR
104 Raised if this node is readonly.
105 * INUSE_ATTRIBUTE_ERR
107 Raised if newAttr is already an attribute of another Element
108 object. The DOM user must explicitly clone Attr nodes to re-use
109 them in other elements.
110 removeAttributeNode (oldAttr)
112 Removes the specified attribute. If the removed Attr has a default
113 value it is immediately replaced. If the Attr already is the
114 default value, nothing happens and nothing is returned.
115 Parameters:
117 oldAttr The Attr node to remove from the attribute list.
118 Return Value: The Attr node that was removed.
120 DOMExceptions:
122 * NO_MODIFICATION_ALLOWED_ERR
124 Raised if this node is readonly.
125 * NOT_FOUND_ERR
127 Raised if oldAttr is not an attribute of the element.
128 Additional methods not in the DOM Spec
130 setTagName (newTagName)
132 Sets the tag name of the Element. Note that this method is not
133 portable between DOM implementations.
134 DOMExceptions:
136 * INVALID_CHARACTER_ERR
138 Raised if the specified name contains an invalid character.
139 check ($checker)
141 Uses the specified XML::Checker to validate the document.
142 NOTE: an XML::Checker must be supplied. The checker can be cre‐
143 ated in different ways, e.g. when parsing a document with
144 XML::DOM::ValParser, or with XML::DOM::Document::create‐
145 Checker(). See XML::Checker for more info.
146perl v5.8.8 2002-02-08 XML::DOM::Element(3)