Stanza.java

package com.voxeo.rayo.client.xmpp.stanza;

import org.dom4j.Element;

import com.voxeo.rayo.client.util.JID;
import com.voxeo.rayo.client.util.JIDImpl;
import com.voxeo.rayo.client.xmpp.extensions.Extension;


/**
 * A stanza is the base class for every message in rayo. It is backed by a Dom4j element. 
 * 
 * There is three different type of stanzas:
 * 
 * <ul>
 *      <li>{@link Message} -- used to send data between users.
 *      <li>{@link Presence} -- contains user presence information or is used
 *          to manage presence subscriptions.
 *      <li>{@link IQ} -- exchange information and perform queries using a
 *          request/response protocol.
 * </ul>
 * 
 * @author martin
 *
 */
public abstract class Stanza<T extends XmppObject> extends AbstractXmppObject {
	
	/**
	 * Creates an empty Stanza element.
	 */
	public Stanza() {
		
		super();
	}
	
	public Stanza(String namespace) {
		
		super(namespace);
	}
	
	/**
	 * Constructs a new Stanza using the given DOM element as data. 
	 * 
	 * @param element DOM element to backup
	 */
	public Stanza(Element element) {
		
		super(element);
	}	
	
	public Stanza(XmppObject xmppObject) {
		
		super(xmppObject);
	}
	
	public String getFrom() {

		//TODO: Lots of stuff. Caching,Stringprep, nodeprep, etc.
		return attribute("from");
	}

    public T setFrom(String from) {

		setAttribute("from", from);
		return asGeneric();
    }
	
	public String getTo() {
		
		//TODO: Lots of stuff. Caching,Stringprep, nodeprep, etc.
		return attribute("to");
	}
	
	public JID getFromJid() {
		
		return new JIDImpl(getFrom());
	}
	
	public JID getToJid() {
		
		return new JIDImpl(getTo());
	}

    public T setTo(String to) {

		setAttribute("to", to);
		return asGeneric();
    }
	
    public T setId(String id) {

        setAttribute("id", id);
        return asGeneric();
    }
    
    /**
     * Reverses this Stanza. This method will swap the values of the 'to' and 'from' fields. 
     *  
     * @return Stanza with the values swapped
     */
    public T reverse() {
    	
    	String from = getFrom();
    	setFrom(getTo());
    	setTo(from);
    	
    	return asGeneric();
    }
    
    @SuppressWarnings("unchecked")
	private T asGeneric() {
    	
    	return (T)this;
    }
    
    /**
     * Sets the packet error using the specified condition. Calling this
     * method will automatically set the packet "type" attribute to "error".
     * This is a convenience method equivalent to calling:
     *
     * <tt>setError(new PacketError(condition));</tt>
     *
     * @param condition the error condition.
     */
    public void setError(Error.Condition condition) {
       
    	setError(new Error(condition));
    }
    
    public void setType(String type) {
    	
    	setAttribute("type", type);
    }
    
    public String getRawType() {
    	
    	return attribute("type");
    }
    
    public T error(Error.Condition condition) {
    	
    	setError(new Error(condition));
    	return asGeneric();
    }
    
    
    public T error(Error.Condition condition, Error.Type type) {
    	
    	setError(new Error(condition,type));
    	return asGeneric();
    }
    
	public T setChild(Extension extension) {
		
		set(extension);
		return (T)this;
	}
	
	public T addChild(XmppObject child) {
		
		add(child);		
		return (T)this;
	}
	
	/**
	 * Sets the child of this IQ object.
	 * 
	 * @param child Child XMPP Object
	 * 
	 * @return {@link AbstractXmppObject} Child XMPP object
	 */
	public T setChild(XmppObject child) {
		
		clearChildren();
		set(child);
		return (T)this;
	}
	
	public boolean hasExtension() {
		
		Element element = getFirstChild();
		if (element == null) {
			return false;
		}
		// Compare with known IQ extensions
		if (element.getName().equals(Error.NAME) ||
			element.getName().equals(Bind.NAME) ||
			element.getName().equals(Query.NAME) ||
			element.getName().equals(Session.NAME)) {
			return false;
		}
		return true;
	}
	
	public Extension getExtension() {
		
		return new Extension(getFirstChild());
	}
}