JavaScriptObject.java

/*
 * See the NOTICE file distributed with this work for additional
 * information regarding copyright ownership.
 *
 * This 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 software 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. See the GNU
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with this software; if not, write to the Free
 * Software Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
 * 02110-1301 USA, or see the FSF site: http://www.fsf.org.
 */
package org.xwiki.gwt.dom.client;

import com.google.gwt.core.client.JsArrayString;

/**
 * Extends GWT JavaScriptObject to add a fromJson method. Usage : <code>
 * public class MyCar extends JavaScriptObject {   
 *     protected MyCar() {}
 *     public final native int getWheelNumber() / *-{ return this.wheelnb; }-* /;
 *     public final native String getColor() / *-{ return this.color; }-* /;
 * }
 * 
 * MyCar redcar = (MyCar) MyCar.fromJson("{ wheelnb: 4, color: 'red' }");
 * redcar.getWheelNumber();
 * redcar.getColor();
 * </code>
 * 
 * @see com.google.gwt.core.client.JavaScriptObject
 * @version $Id: 5cb1a9993cca01ebdf68590a4344dbb737a69cd9 $
 */
public class JavaScriptObject extends com.google.gwt.core.client.JavaScriptObject
{
    /**
     * Default constructor. Overlay types always have protected, zero-arguments constructors.
     */
    protected JavaScriptObject()
    {
    }

    /**
     * Create a JavaScriptObject from a JSON string.
     * 
     * @param input a valid JSON string.
     * @return resulting JavaScriptObject
     */
    public static final native JavaScriptObject fromJson(String input)
    /*-{ 
         return eval('(' + input + ')') 
    }-*/;

    /**
     * Returns the reference stored in this JavaScript object for the given key.
     * 
     * @param key the key whose value to return
     * @return the value of the specified key
     */
    public final native Object get(String key)
    /*-{
        return this[key];
    }-*/;

    /**
     * Saves the given reference in this JavaScript object using the specified key.
     * 
     * @param key the string used for storing and retrieving the reference
     * @param ref the object whose reference will be stored
     * @return the previous reference associated with the given key
     */
    public final native Object set(String key, Object ref)
    /*-{
        var oldRef = this[key];
        this[key] = ref;
        return oldRef;
    }-*/;

    /**
     * Removes a property from this JavaScript object.
     * 
     * @param key the name of the property to be removed
     * @return the value of the removed property
     */
    public final native Object remove(String key)
    /*-{
        var value = this[key];
        try {
            delete this[key];
        } catch (e) {
            // In IE 6 and 7, removing any dynamic property from a DOM instance, interface objects, or interface
            // prototype objects with the delete operator causes a script error; IE 8 properly removes the dynamic
            // property.
            this[key] = undefined;
        }
        return value;
    }-*/;

    /**
     * Returns all the keys set in this JavaScript object, to use with {@link JavaScriptObject#get(String)} to iterate
     * over all properties, without knowing their names.
     * 
     * @return the array of keys set in this JavaScript object
     */
    public final native JsArrayString getKeys()
    /*-{
           var keys = [];
           for (var key in this){
              keys.push(key);
           }
           return keys;
    }-*/;

    /**
     * @param key the name of a property of this JavaScript object
     * @return the type of value assigned to the specified property
     */
    public final native JavaScriptType typeOf(String key)
    /*-{
        var type = (typeof this[key]).toUpperCase();
        return @org.xwiki.gwt.dom.client.JavaScriptType::valueOf(Ljava/lang/String;)(type);
    }-*/;
}