/*
 * Copyright 2001-2004 The Apache Software Foundation.
 * 
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 * 
 *      http://www.apache.org/licenses/LICENSE-2.0
 * 
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */ 
package org.apache.commons.betwixt;

/** <p> Common superclass for <code>ElementDescriptor</code> 
  * and <code>AttributeDescriptor</code>.</p>
  *
  * <p> Nodes can have just a local name
  * or they can have a local name, qualified name and a namespace uri.</p>
  *
  * @author <a href="mailto:jstrachan@apache.org">James Strachan</a>
  * @version $Revision: 1.10 $
  */
public class NodeDescriptor extends Descriptor {

    /** The local name of this node without any namespace prefix */
    private String localName;
    /** The qualified name of the xml node associated with this descriptor. */
    private String qualifiedName;
    /** The namespace URI of this node */
    private String uri = "";
    
    /** Base constructor */
    public NodeDescriptor() {
    }

    /** 
     * Creates a NodeDescriptor with no namespace URI or prefix.
     *
     * @param localName the (xml) local name of this node. 
     * This will be used to set both qualified and local name for this name.
     */
    public NodeDescriptor(String localName) {
        this.localName = localName;
        this.qualifiedName = localName;
    }


    /**  
     * Creates a NodeDescriptor with namespace URI and qualified name 
     * @param localName the (xml) local name of this  node
     * @param qualifiedName the (xml) qualified name of this node
     * @param uri the (xml) namespace prefix of this node
     */
    public NodeDescriptor(String localName, String qualifiedName, String uri) {
        this.localName = localName;
        this.qualifiedName = qualifiedName;
        this.uri = uri;
    }

    /** 
     * Gets the local name, excluding any namespace prefix 
     * @return the (xml) local name of this node
     */
    public String getLocalName() {
        return localName;
    }

    /** 
     * Sets the local name 
     * @param localName the (xml) local name of this node
     */
    public void setLocalName(String localName) {
        this.localName = localName;
    }    
    
    /** 
     * Gets the qualified name, including any namespace prefix 
     * @return the (xml) qualified name of this node. This may be null.
     */
    public String getQualifiedName() {
        if ( qualifiedName == null ) {
            qualifiedName = localName;
        }
        return qualifiedName;
    }
    
    /** 
     * Sets the qualified name
     * @param qualifiedName the new (xml) qualified name for this node
     */
    public void setQualifiedName(String qualifiedName) {
        this.qualifiedName = qualifiedName;
    }    
    
    /**  
     * Gets the (xml) namespace URI prefix for this node.
     * @return the namespace URI that this node belongs to 
     * or "" if there is no namespace defined 
     */
    public String getURI() {
        return uri;
    }
    

    /** 
     * Sets the namespace URI that this node belongs to.
     * @param uri the new namespace uri for this node
     */
    public void setURI(String uri) {
        if ( uri == null ) {
            throw new IllegalArgumentException( 
                "The namespace URI cannot be null. " 
                + "No namespace URI is specified with the empty string" 
            );
        }
        this.uri = uri;
    }
}