Biggest GWT Pitfalls? [closed]

Answer 1

I'm working on a project right now that uses EXT GWT (GXT) not to be confused with GWT EXT. There is a difference, EXT GWT is the one that is actually produced by the company that wrote ExtJS the javascript library. GWT EXT is a GWT wrapper around the ExtJS library. GXT is native GWT.

Anyways, GXT is still somewhat immature and lacks a solid community that I feel GWT EXT has. However, the future is with GXT, as it's native GWT and actually developed by the company that made ExtJS. GWT EXT is somewhat crippled as the license changed on the ExtJS library, thus slowing the development of GWT EXT.

Overall, I think GWT/GXT is a good solution for developing a web application. I actually quite like hosted mode for development, it makes things quick and easy. You also get the benefit of being able to debug your code as well. Unit testings with JUnit is pretty solid as well. I haven't yet seen a great JavaScript unit testing framework that I felt was mature enough for testing an enterprise application.

For more information on GWT EXT: http://gwt-ext.com/

For more information on EXT GWT (GXT): http://extjs.com/products/gxt/

Answer 2

Regarding GWT 2.4, Use Firefox when debugging GWT, it alot more faster then using chrome. And if you'll using only firefox, consider putting this line in your project.gwt.xml file

<set-property name="user.agent" value="gecko1_8" />

Also, If you're using eclipse, then add the following under arguments -> VM arguments:

-Xmx512m -XX:MaxPermSize=1024m -XX:PermSize=1024m

You can divide your server and client, and use the following under arguments -> Program arguments: -codeServerPort 9997 -startupUrl http://yourserver/project -noserver

Also, to prevent refreshing your server on each change, use JRebel http://zeroturnaround.com/blog/how-to-rock-out-with-jrebel-and-google-web-toolkit-gwt/ And here's a live demo http://www.youtube.com/watch?feature=player_embedded&v=4JGGFCzspaY

Answer 3

The best way to get reliable facts are from the gwt survey. One of the biggest issues with GWT has always been a long compile time. Fortunately, it's improving very quickly so it won't be a significant issue in the near future. Another pitfall is that GWT is dramatically more complicated because Java is a more complicated language that resists bad coders every step of the way. In addition, compiling adds a layer. For example, js interop requires a little boilerplate. The fundamental issue is that GWT wasn't designed to be simple. It was designed from the ground up for extremely complicated web apps and the entire community consistently prioritizes, performance, code quality, architecture etcetera over easy coding.
Remember that you can use js in GWT at any point so if you are struggling with GWT consider using js. At the end of the day GWT is js so you can do anything in GWT that you can in js. In fact, most GWT projects use js. The problem is that GWT is drastically more complicated. Nevertheless, it's sometimes worth the extra complexity.

It's worth noting that GWT 3.0 will bring massive improvements.

Answer 4

Pitfalls that we've run into:

• While you can get a lot of mileage from using something like GWT EXT, any time you use this sort of thin veneer on top of a JavaScript library, you lose the ability to debug. More than once I've bashed my head on the desk because I cannot inspect (inside my IntelliJ debugger) what's happening in the GWT EXT table class... All you can see is that it's a JavaScriptObject. This makes it quite difficult to figure out what's gone wrong...

• Not having someone on your team who knows CSS. From my experience, it didn't matter that the person wasn't expert...it's enough that he has some good working knowledge, and knows the right terms to google when necessary.

• Debugging across browsers. Keep an eye on Out of Process Hosted Mode[1][2][3], hopefully coming in GWT 1.6... For now, you just have to get things good with hosted mode, then use the "Compile/Browse" button, where you can play with other browsers. For me, working on Windows, this means I can view my work in FireFox, and use FireBug to help tweak and make things better.

• IE6. It's amazing how different IE 6 will render things. I've taken the approach of applying a style to the outermost "viewport" according to the browser so that I can have CSS rules like:

  .my-style { /* stuff that works most everywhere */ }
  
  .msie6 .my-style { /* "override" so that styles work on IE 6 */ }
  

Finally, make sure you use an editor that helps you. I use IntelliJ -- it's got lots of GWT smarts. E.g., If I try to use a class that isn't handled by the JRE emulation, it lets me know; if I specify a style for a widget, and I haven't defined that style yet, the code gets the little red squiggly... Or, when looking at the CSS, it will tell me when I've specified conflicting attributes in a single rule. (I haven't tried it yet, but I understand that version 8 has even better GWT support, like keeping the "local" and "async" RPC interfaces and implementations in sync.)

Answer 5

GWT 2.4 has fixed many of the aforementioned issues and a great widget library is just coming out of Beta (Ext GWT 3.0.4 a.k.a. GXT), which is written completely in GWT, not a wrapper of a JS lib.

Remaining pain:

• Lack of CSS3 selector support, you can use "literal()" in some cases to get around it.
• Lack of support for CSS3 and modern browser events like transitionEnd.
• Lack of Java Calendar class support (many years later).
• Lack of JUnit4 support (5 years and counting).
• Lack of clear road map and release schedule from Google GWT team.

Answer 6

The GWT team make a lot of great improvements in to last year releasing GWT 2.7. One major weakness of GWT was that compilation takes to much time in GWT 2.6 and below. This is now gone GWT has not incremental compile which is super fast and compiles only the changes.

GWT 2.7 now has (Source):

• Incremental builds now just seconds
• More compact, more accurate SourceMaps
• GSS support
• JSInterop
• Great JavaScript Performance
• Smaller Code Size