XML::DOM::Element

XML::DOM::Element(3)  User Contributed Perl Documentation XML::DOM::Element(3)



NAME
       XML::DOM::Element - An XML element node in XML::DOM

DESCRIPTION
       XML::DOM::Element extends XML::DOM::Node.

       By far the vast majority of objects (apart from text) that authors
       encounter when traversing a document are Element nodes. Assume the fol-
       lowing XML document:

            <elementExample id="demo">
              <subelement1/>
              <subelement2><subsubelement/></subelement2>
            </elementExample>

       When represented using DOM, the top node is an Element node for "ele-
       mentExample", which contains two child Element nodes, one for "subele-
       ment1" and one for "subelement2". "subelement1" contains no child
       nodes.

       Elements may have attributes associated with them; since the Element
       interface inherits from Node, the generic Node interface method getAt-
       tributes may be used to retrieve the set of all attributes for an ele-
       ment. There are methods on the Element interface to retrieve either an
       Attr object by name or an attribute value by name. In XML, where an
       attribute value may contain entity references, an Attr object should be
       retrieved to examine the possibly fairly complex sub-tree representing
       the attribute value. On the other hand, in HTML, where all attributes
       have simple string values, methods to directly access an attribute
       value can safely be used as a convenience.

       METHODS


       getTagName
           The name of the element. For example, in:

                          <elementExample id="demo">
                                  ...
                          </elementExample>

           tagName has the value "elementExample". Note that this is case-pre-
           serving in XML, as are all of the operations of the DOM.

       getAttribute (name)
           Retrieves an attribute value by name.

           Return Value: The Attr value as a string, or the empty string if
           that attribute does not have a specified or default value.

       setAttribute (name, value)
           Adds a new attribute. If an attribute with that name is already
           present in the element, its value is changed to be that of the
           value parameter. This value is a simple string, it is not parsed as
           it is being set. So any markup (such as syntax to be recognized as
           an entity reference) is treated as literal text, and needs to be
           appropriately escaped by the implementation when it is written out.
           In order to assign an attribute value that contains entity refer-
           ences, the user must create an Attr node plus any Text and Enti-
           tyReference nodes, build the appropriate subtree, and use setAt-
           tributeNode to assign it as the value of an attribute.

           DOMExceptions:

           * INVALID_CHARACTER_ERR
               Raised if the specified name contains an invalid character.

           * NO_MODIFICATION_ALLOWED_ERR
               Raised if this node is readonly.

       removeAttribute (name)
           Removes an attribute by name. If the removed attribute has a
           default value it is immediately replaced.

           DOMExceptions:

           * NO_MODIFICATION_ALLOWED_ERR
               Raised if this node is readonly.

       getAttributeNode
           Retrieves an Attr node by name.

           Return Value: The Attr node with the specified attribute name or
           undef if there is no such attribute.

       setAttributeNode (attr)
           Adds a new attribute. If an attribute with that name is already
           present in the element, it is replaced by the new one.

           Return Value: If the newAttr attribute replaces an existing
           attribute with the same name, the previously existing Attr node is
           returned, otherwise undef is returned.

           DOMExceptions:

           * WRONG_DOCUMENT_ERR
               Raised if newAttr was created from a different document than
               the one that created the element.

           * NO_MODIFICATION_ALLOWED_ERR
               Raised if this node is readonly.

           * INUSE_ATTRIBUTE_ERR
               Raised if newAttr is already an attribute of another Element
               object. The DOM user must explicitly clone Attr nodes to re-use
               them in other elements.

       removeAttributeNode (oldAttr)
           Removes the specified attribute. If the removed Attr has a default
           value it is immediately replaced. If the Attr already is the
           default value, nothing happens and nothing is returned.

           Parameters:
            oldAttr  The Attr node to remove from the attribute list.

           Return Value: The Attr node that was removed.

           DOMExceptions:

           * NO_MODIFICATION_ALLOWED_ERR
               Raised if this node is readonly.

           * NOT_FOUND_ERR
               Raised if oldAttr is not an attribute of the element.

           Additional methods not in the DOM Spec


           setTagName (newTagName)
               Sets the tag name of the Element. Note that this method is not
               portable between DOM implementations.

               DOMExceptions:

               * INVALID_CHARACTER_ERR
                   Raised if the specified name contains an invalid character.

           check ($checker)
               Uses the specified XML::Checker to validate the document.
               NOTE: an XML::Checker must be supplied. The checker can be cre-
               ated in different ways, e.g. when parsing a document with
               XML::DOM::ValParser, or with XML::DOM::Document::create-
               Checker().  See XML::Checker for more info.



perl v5.8.6                       2002-02-08              XML::DOM::Element(3)