addattr.html
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<TITLE>Adding and Removing an Attribute in a DOM Element
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<h3>
e535.
Adding and Removing an Attribute in a DOM Element</h3>
If any special characters appear in the value of an attribute
(e.g., <>"), they are automatically converted to entities by the XML writers.
<pre>
// Obtain an element; this method is implemented in
// <a href="../javax.xml.parsers/BasicDom.html" class="eglink"><font size="-1"><b>e510</b> The Quintessential Program to Create a DOM Document from an XML File</font></a>
Document doc = <font color="#0066ff"><i>parseXmlFile</i></font>(<font color="#0066ff"><i>"infilename.xml"</i></font>, <font color="#0066ff"><i>true</i></font>);
Element element = doc.getElementById(<font color="#0066ff"><i>"key1"</i></font>);
// Add an attribute
element.setAttribute(<font color="#0066ff"><i>"newAttrName"</i></font>, <font color="#0066ff"><i>"attrValue"</i></font>);
// Change the value of an attribute.
// Special characters are automatically converted to entities by the XML writer.
element.setAttribute(<font color="#0066ff"><i>"newAttrName"</i></font>, <font color="#0066ff"><i>"<>&\"'"</i></font>);
// Remove an attribute
element.removeAttribute(<font color="#0066ff"><i>"value"</i></font>);
// However, if the attribute has a default value, the attribute cannot be removed
boolean has = element.hasAttribute(<font color="#0066ff"><i>"value"</i></font>); // true
// The effect of removing an attribute with a default value
// is to set the attribute to the default value
String attrValue = element.getAttribute(<font color="#0066ff"><i>"value"</i></font>); // mydefault
</pre>
This is the sample input for the example:
<pre>
<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE map [ <!ELEMENT map (entry*) >
<!ELEMENT entry EMPTY >
<!ATTLIST entry key ID #REQUIRED
value CDATA "mydefault"> ]>
<map>
<entry key="key1" value="value1"/>
<entry key="key2" />
</map>
</pre>
The resulting XML from running the example is:
<pre>
<?xml version="1.0" encoding="UTF-8"?>
<map>
<entry key="key1" newAttrName="&lt;&gt;&amp;&quot;'" value="mydefault"/>
<entry key="key2" value="mydefault"/>
</map>
</pre>
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Related Examples
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e534. <a class="eglink" href="GetAttr.html?l=rel">
Getting and Setting an Attribute in a DOM Element
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e536. <a class="eglink" href="GetAllAttr.html?l=rel">
Listing All the Attributes of a DOM Element
</a>
<br>
e537. <a class="eglink" href="RemAllAttr.html?l=rel">
Removing All the Attributes in a DOM Element
</a>
<br>
e538. <a class="eglink" href="IfAttr.html?l=rel">
Determining If an Attribute Was Supplied in a DOM Element
</a>
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See also:
<a class="eglink" href="/egs/org.w3c.dom/pkg.html?l=rel#Adding%20and%20Removing%20Nodes">
Adding and Removing Nodes
</a>
<a class="eglink" href="/egs/org.w3c.dom/pkg.html?l=rel#Elements">
Elements
</a>
<a class="eglink" href="/egs/org.w3c.dom/pkg.html?l=rel#Getting%20Nodes">
Getting Nodes
</a>
<a class="eglink" href="/egs/org.w3c.dom/pkg.html?l=rel#Text%20Nodes">
Text Nodes
</a>
<a class="eglink" href="/egs/org.w3c.dom/pkg.html?l=rel#XPath">
XPath
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