org.directwebremoting.extend.DefaultJavascriptObject Maven / Gradle / Ivy

Go to download
Show more of this group Show more artifacts with this name
Show all versions of dwr Show documentation
DWR is easy Ajax for Java. It makes it simple to call Java code directly from Javascript. It gets rid of almost all the boiler plate code between the web browser and your Java code.
The newest version!
/*
 * Copyright 2005 Joe Walker
 *
 * 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.directwebremoting.extend;

import java.lang.reflect.InvocationHandler;
import java.lang.reflect.Method;

import org.directwebremoting.ScriptBuffer;
import org.directwebremoting.ScriptSession;
import org.directwebremoting.io.JavascriptObject;

/**
 * Represents a callback function, passed in from a client for later execution.
 * A DefaultJavascriptFunction is tied to a specific function in a specific browser
 * page. In this way the eval of a DefaultJavascriptFunction is outside of the normal
 * execution scoping provided by {@link org.directwebremoting.Browser}.
 * @author Joe Walker [joe at getahead dot ltd dot uk]
 */
public class DefaultJavascriptObject implements JavascriptObject, InvocationHandler
{
    public DefaultJavascriptObject(ScriptSession session, String id)
    {
        this.session = session;
        this.id = id;
    }

    /* (non-Javadoc)
     * @see java.lang.reflect.InvocationHandler#invoke(java.lang.Object, java.lang.reflect.Method, java.lang.Object[])
     */
    public Object invoke(Object proxy, Method method, Object[] args) throws Throwable
    {
        if (method.getName().equals("equals") && args.length == 1)
        {
            return equals(args[0]);
        }

        if (method.getName().equals("hashCode") && (args == null || args.length == 0))
        {
            return hashCode();
        }

        if (method.getName().equals("toString") && (args == null || args.length == 0))
        {
            return toString();
        }

        ScriptBuffer script = EnginePrivate.getRemoteExecuteObjectScript(id, method.getName(), args);
        session.addScript(script);
        return null;
    }

    /* (non-Javadoc)
     * @see org.directwebremoting.io.JavascriptObject#execute(String, java.lang.Object[])
     */
    public void execute(String methodName, Object... params)
    {
        ScriptBuffer script = EnginePrivate.getRemoteExecuteObjectScript(id, methodName, params);
        session.addScript(script);
    }

    /**
     * Add a property to a JavaScript object. The type of the data must be
     * convertible by DWR.
     */
    public void set(String propertyName, Object data)
    {
        ScriptBuffer script = EnginePrivate.getRemoteSetObjectScript(id, propertyName, data);
        session.addScript(script);
    }

    /* (non-Javadoc)
     * @see org.directwebremoting.io.JavascriptFunction#close()
     */
    public void close()
    {
        ScriptBuffer script = EnginePrivate.getRemoteCloseFunctionScript(id);
        session.addScript(script);
    }

    /* (non-Javadoc)
     * @see java.lang.Object#toString()
     */
    @Override
    public String toString()
    {
        return "browser[" + session.getId() + "].object[" + id + "](...)";
    }

    /* (non-Javadoc)
     * @see java.lang.Object#equals(java.lang.Object)
     */
    @Override
    public boolean equals(Object obj)
    {
        if (obj == this)
        {
            return true;
        }

        if (obj == null || this.getClass() != obj.getClass())
        {
            return false;
        }

        DefaultJavascriptObject that = (DefaultJavascriptObject) obj;

        if (!this.session.equals(that.session))
        {
            return false;
        }

        if (!this.id.equals(that.id))
        {
            return false;
        }

        return true;
    }

    /* (non-Javadoc)
     * @see java.lang.Object#hashCode()
     */
    @Override
    public int hashCode()
    {
        int hash = 345;
        hash += (id == null) ? 768 : id.hashCode();
        hash += (session == null) ? 546 : session.hashCode();
        return hash;
    }

    /**
     * The browser window that owns this function
     */
    private ScriptSession session;

    /**
     * The id into the function cache
     */
    private String id;
}