com.hp.hpl.sparta

Class Element

java.lang.Object

com.hp.hpl.sparta.Node

com.hp.hpl.sparta.Element

public class Element
extends Node

A type of Node with a particular tagName that has a set of attributes and can contain other nodes as children. An example of its form in XML in the form

 <tagName attr1="value1" attr2="value2">
 text
 <childTag...>
 <childTag...>
 text
 <childTag...>
 text
 </tagName>
 

Copyright (C) 2002 Hewlett-Packard Company. This file is part of Sparta, an XML Parser, DOM, and XPath library. This library is free software; you can redistribute it and/or modify it under the terms of the GNU Lesser General Public License as published by the Free Software Foundation; either version 2.1 of the License, or (at your option) any later version. This library is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.

Version:

$Date: 2003/10/28 00:25:11 $ $Revision: 1.10 $

Author:

Eamonn O'Brien-Strain

See Also:

GNU Lesser General Public License, Element

Constructor Summary

Constructors

Constructor and Description
Element(String tagName)

Method Summary

Methods

Modifier and Type	Method and Description
void	appendChild(Node addedChild) Add node as child of this element, cloning node if it is this element or an ancestor.
Object	clone() Create a deep clone of this Element.
Element	cloneElement(boolean deep) Create a clone of this node.
Element	cloneShallow() Create a shallow clone of this Element.
protected int	computeHashCode() Called whenever cached version of hashCode needs to be regenerated.
boolean	equals(Object thatO) To be equal elements must have the same tagname, they must have the same children (applying equals recursivly) in the same order and they must have the same attributes in any order.
String	getAttribute(String name)
Enumeration	getAttributeNames() Return enumeration of Strings
Node	getFirstChild()
Node	getLastChild()
String	getTagName()
void	removeAttribute(String name) remove this attribute if it exists, otherwise silently do nothing.
void	removeChild(Node childToRemove)
void	replaceChild(Element newChild, Node oldChild) Replace oldChild with newChild.
void	replaceChild(Text newChild, Node oldChild) Replace oldChild with newChild.
void	setAttribute(String name, String value)
void	setTagName(String tagName)
void	toXml(Writer writer) Write XML representation to character stream.
boolean	xpathEnsure(String xpath) Make sure this XPath exists, creating nodes if necessary, returning true if any nodes created.
Element	xpathSelectElement(String xpath) Select the first element that matches the relative XPath expression with respect to this element, or null if there is no match.
Enumeration	xpathSelectElements(String xpath) Select all the elements that match the relative XPath expression with respect to this element.
String	xpathSelectString(String xpath) Select the first element that matches the relative XPath expression with respect to this element, or null if there is no match.
Enumeration	xpathSelectStrings(String xpath) Select all the strings that match the relative XPath expression with respect to this element.

Methods inherited from class com.hp.hpl.sparta.Node

getAnnotation, getNextSibling, getOwnerDocument, getParentNode, getPreviousSibling, hashCode, htmlEncode, setAnnotation, toString, toXml, xpathSetStrings

Methods inherited from class java.lang.Object

finalize, getClass, notify, notifyAll, wait, wait, wait

Constructor Detail

Element

public Element(String tagName)

Method Detail

clone

public Object clone()

Create a deep clone of this Element. It will have the tagname and attributes as this node. This method will be called recursively to copy the while subtree of child Elements and Text nodes.

Specified by:

clone in class Node

cloneShallow

public Element cloneShallow()

Create a shallow clone of this Element. It will have the tagname and attributes as this Element but will not have child Elements or Nodes.

cloneElement

public Element cloneElement(boolean deep)

Create a clone of this node. It will have the tagname and attributes as this node. If deep is true, this method will be called recursively to copy the while subtree of child Elements and text nodes.

getTagName

public String getTagName()

Returns:

tag as interned string.

setTagName

public void setTagName(String tagName)

getFirstChild

public Node getFirstChild()

Returns:

either an Element or a Text node

getLastChild

public Node getLastChild()

Returns:

either an Element or a Text node

getAttributeNames

public Enumeration getAttributeNames()

Return enumeration of Strings

getAttribute

public String getAttribute(String name)

Returns:

value of attribute that has this name or null if no such attribute. WARNING! Unlike in a previous version of this API, this string is not interned therefore you must do a.equals(b) instead of a==b when comparing attribute values.

setAttribute

public void setAttribute(String name,
                String value)

Parameters:

name - attribute name which must be non-null, non empty

value - attribue value.

removeAttribute

public void removeAttribute(String name)

remove this attribute if it exists, otherwise silently do nothing.

appendChild

public void appendChild(Node addedChild)

Add node as child of this element, cloning node if it is this element or an ancestor.

removeChild

public void removeChild(Node childToRemove)
                 throws DOMException

Throws:

DOMException

replaceChild

public void replaceChild(Element newChild,
                Node oldChild)
                  throws DOMException

Replace oldChild with newChild.

Throws:

DOMException - if oldChild object is not a child.

replaceChild

public void replaceChild(Text newChild,
                Node oldChild)
                  throws DOMException

Replace oldChild with newChild.

Throws:

DOMException - if oldChild object is not a child.

toXml

public void toXml(Writer writer)
           throws IOException

Write XML representation to character stream.

Throws:

IOException

xpathSelectElements

public Enumeration xpathSelectElements(String xpath)
                                throws ParseException

Select all the elements that match the relative XPath expression with respect to this element.

Specified by:

xpathSelectElements in class Node

Throws:

ParseException

xpathSelectStrings

public Enumeration xpathSelectStrings(String xpath)
                               throws ParseException

Select all the strings that match the relative XPath expression with respect to this element.

Specified by:

xpathSelectStrings in class Node

Throws:

ParseException

xpathEnsure

public boolean xpathEnsure(String xpath)
                    throws ParseException

Make sure this XPath exists, creating nodes if necessary, returning true if any nodes created. Xpath must of the type that returns an element (not a string).

Throws:

ParseException

xpathSelectElement

public Element xpathSelectElement(String xpath)
                           throws ParseException

Select the first element that matches the relative XPath expression with respect to this element, or null if there is no match.

Specified by:

xpathSelectElement in class Node

Throws:

ParseException

xpathSelectString

public String xpathSelectString(String xpath)
                         throws ParseException

Select the first element that matches the relative XPath expression with respect to this element, or null if there is no match.

Specified by:

xpathSelectString in class Node

Throws:

ParseException

equals

public boolean equals(Object thatO)

To be equal elements must have the same tagname, they must have the same children (applying equals recursivly) in the same order and they must have the same attributes in any order. Elements can be equal even if they are in different documents, have different parents, have different siblings, or have different annotations.

Overrides:

equals in class Object

computeHashCode

protected int computeHashCode()

Called whenever cached version of hashCode needs to be regenerated.

Specified by:

computeHashCode in class Node