Friday, November 07, 2008

Games: Little Big Planet

I try not to blog about gaming too much since there are far better sources for this kind of material, some better, some worse, but thats all a matter of taste. I do have to say though, as an avid gamer, Little Big Planet has knocked my socks off. I picked this game up mainly due to hype, and half expecting to be let down. Truth be told, when I got the game home and couldn't update to the latest version (at this time, 1.03), I was really disappointed since it wouldn't allow me to see user created content. So I was left with the stock levels.

I won't bore you with the details about "Sackboy" since the main character and his possible customizations are covered very well in depth by the many gaming rags on the market. I will say he is cute and clever, as is the control scheme for him. I can't help myself but to have him disco dance ala Saturday Night Fever after every level.

The stock levels showcase the games physics and themes really well. It has a very animatronic theme going, with characters being voiced by little speakers, and movements being done by something right out of a Rube Goldberg invention. They are challenging, with a very silly backstory behind many of the different levels.

Once the gremlins with the network, be in on my end or Sonys end finally cleared up and I was able to update, I got to see where LBP really shines. User created content always ends up enhancing a game, and showcasing possibilities that the developers couldn't imagine. In this case there is no exception. I played around with user levels, some of which were mere mechanisms to earn trophies, but others were clever, challenging platformers that brought me back to the yesteryears of the NES. I had one level where I was doing a mock prison break, another where I was going through the American Gladiators obstacle course, and one where I played basketball while wearing a rocketpack.

So, those are the facts, so whats my opinion. I can openly say this, and all naysayers be damned. This is the first game where I have actually smiled and enjoyed playing. I haven't even gotten into level creation, just playing, and this is easily one of the most enjoyable gaming experiences I have had in a long time. Finally, something that breaks away from the tired first person shooters, dystopian futures, survival horrors, and the getting very thin rhythm games (although I did pick up Gears of War 2, Guitar Hero World Tour, and Rock Band 2, so apparently I still have some demand for these games). Easily the best game for the PS3, and I look forward to seeing what else the community can cook up.

Thursday, November 06, 2008

GWT: Calling GWT Classes and Methods from Regular Javascript

My current project involves us working with a group who uses a custom built web framework that works on top of Dojo. Since I prefer to use GWT, even for strictly client side Javascript due to the debugger, I needed something that would allow me to create a somewhat functional Javascript based library. Out of the box, doing so in GWT is a bit of a pain, involving the need to create native JSNI mappings to the GWT methods. This is ugly, and one of the reasons I like GWT is because the code can be much prettier in development, even if it is not in deployment. I would prefer a much more efficient way, where the creation of the publically exposed methods are hidden for the most part during the development. This would normally take some function of the compiler to do this, but the clever folks behind the GWT Chronoscope project figured out a way to do this using Generators. They were even nice enough to release the fruits of that work free of charge.

Now, I will give you fair warning, download the sample code from the SVN repository. The documentation for this is non-existent, and the only way you can figure anything out is by looking at the samples. Here I will try to give you a good idea how to implement this in your own code by using a real simple proof of concept.

In the following example, I am going to create a new GWT module that will expose a simple Hello World return to a DOM object whose ID will be passed in. I will be doing so in a GWT project in Eclipse, and my runtime stuff will be done using the Instantiations GWT Designer, although you can do this in any GWT IDE you like. This will be compiled against GWT 1.5.2.

The first thing you need to do is add the library for GWT-Exporter into your projects classpath. In my case, I am using the Alpha release for version 2.

Once added, I create a simple module with a blank onModuleLoad. Normally in the onModuleLoad, we want to load and prepare out Ajax based stuff, but in this case, I don’t want anything yet, I will add a little code to jumpstart the export process in a bit. First, I want to create a class that looks like so:

package com.digiassn.blogspot.client;

import org.timepedia.exporter.client.Export;
import org.timepedia.exporter.client.ExportPackage;
import org.timepedia.exporter.client.Exportable;


public class UpdateWithHelloWorld implements Exportable {
public void UpdateMyDomObject(String id)
DOM.getElementById(id).setInnerHTML("Hello World");

Also note the annotations for package and Export. This tells the generator that this class is to be exported, and that it is accessible by that package name.

With that class there is a slight problem. The Exportable class is not set up properly in the GWT Modules XML file. So I need to modify my ExporterExample.gwt.xml file to contain the Exportable class. Be sure to add in the option to export, otherwise it won't export your classes.

<inherits name=""/>
<inherits name=''/>
<entry-point class="com.digiassn.blogspot.client.ExporterExample"/>

<inherits name="org.timepedia.exporter.Exporter"/>
<set-property name="export" value="yes"/>

Now I can go ahead and update my onModuleLoad to tell the GWT-Export to export UpdateWithHelloWorld for outside Javascript to use.

package com.digiassn.blogspot.client;

import org.timepedia.exporter.client.Exporter;


* Entry point classes define <code>onModuleLoad()</code>.
public class ExporterExample implements EntryPoint {
public void onModuleLoad() {
try {
Exporter export = (Exporter)GWT.create(UpdateWithHelloWorld.class);
} catch (Exception e) {
Window.alert("Exception " + e.toString());

For now, I want to open my public HTML page, and create two things, the DIV tag that will be updated, and a small Javascript method that will call my GWT class. I use the following as a small test.

<title>Wrapper HTML for ExporterExample</title>
<link type="text/css" rel='stylesheet' href='ExporterExample.css'/>

<script language="javascript" src="com.digiassn.blogspot.ExporterExample.nocache.js"></script>

<script language="javascript">
function updateText()
var hello = new helloworld.UpdateWithHelloWorld();

<div id="updateMe">I show nothing right now</div>
<input type="button" onclick="updateText();">

And whala, when I click on my button, it will update my DOM code using the GWT. This demonstrates that a GWT based class and method are called from and outside Javascript.

You got to hand it to the guys over at Timepedia, this is a pretty cool little library. Now it is possible for me to do any Javascript based development, debugging, and re-use of components with my development in GWT for reliability and cross-browser support, and use in non-GWT based calls.