I like JavaScript, and I'm not worried that saying so will cause me to take a pay-cut. I have some tools I like to use to deal with it. One is a bookmarklet I found for viewing XMLHttpRequests and responses. It works really well in Internet Explorer 7.
I was playing with my little app on IE, and decided to open up my bookmarklet to see exactly what the GWT-generated JavaScript sent to the server. What did I see? Nothing at all...
Ok, time to get serious. I switched over to Firefox, where I have every web developer's best friend, Firebug, installed. I flipped the switch on Firebug and repeated the same process. What did I see here? Again nothing. Nada.
What the heck was going on? I see the request hitting the server and the response causing the data on the page to be changed. Yet somehow these common debugging tools were oblivious to what was going on. Was there an inviso-IFrame being used? That would be so Web 1.0-ish.
I probed around with Firebug, and indeed there was a massive hidden IFrame on my page. I opened it up and saw that there was a GWT-generated HTML page that was being dumped in here. That page contained tons of JavaScript. And not just any JavaScript, but amazingly obfuscated JavaScript. Here's a sample of it:
function gX(hX,iX){hX.aX = iX;}
function jX(kX){return kX.cX;}
function lX(mX,nX){mX.cX = nX;}
function oX(pX){return pX.bX;}
function qX(rX,sX){rX.bX = sX;}
function tX(uX,vX){uX.fo(eX(vX));uX.cq(jX(vX));uX.fo(oX(vX));}
function wX(xX,yX){gX(yX,xX.jo());lX(yX,xX.Ep());qX(yX,xX.jo());}
I don't know what to say about this stuff, but it's not the point. This wacky IFrame was where all the magic happened. It's the use of this IFrame and its Skynet-like JS that allows the GWT guys to claim:
Your GWT applications automatically support IE, Firefox, Mozilla, Safari, and Opera with no browser detection or special-casing within your code in most cases.
They're not using the sexiest flavor of AJAX, they're using the lowest-common-denominator version of it.
