混合GWT和Ext GWT

Question

I use Ext GWT in my project. Why is it recommended to use a minimal amount of native GWT widgets and classes when using Ext GWT? Is it because of increases in the size of the client-side code package or some other reason?

Answer 1

I wouldn't jump at the chance to use Ext GWT, because the real "danger" is future portability and maintainability concerns. The reason you'd be recommended not to mix too many native GWT widgets with Ext GWT widgets is because Ext's widgets have a different "look and feel" than their native GWT cousins. GWT uses (mostly) native HTML elements, whereas Ext GWT uses almost completely custom elements.

One example is Ext's ComboBox (left), which looks nothing like GWT's ListBox (right).

vs

That's on Windows. On Mac, there's even more disparity.

The CSS, though, doesn't collide. Ext GWT uses custom style names, which are prefixed by x- or ext- , whereas GWT style names begin with gwt- .

So my take is this: if you're looking to add some cool widgets at the expense of future portability and maintainability, go with Ext GWT. If you have any intention of potentially removing the proprietary Ext GWT stuff later, you're probably shooting yourself in the foot over a few pretty UI elements. There's hardly any concept of "just UI" with Ext stuff. You're all but forced to deeply integrate it.

For the record, I used Ext GWT for a bunch of stuff, only to later bear the pain of removing the proprietary elements later. In retrospect, I never should have done it.

Answer 2

EXT GWT is based on GWT and extends it by providing a beautiful set of UI elements. These elements are generated by creating custom CSS which you don't have direct access to. Whereas in the case of GWT, all Widgets are modifiable with the CSS file of the project.

So, it is not a good way to mix 2 programming languages where in the first you cannot control its CSS and in the 2nd you can do that. There might also be conflicts in case you have same style names.

Also, as this link says, there are some inconsistency while mixing components from different GWT extensions such as smartgwt and gwt (the same applies to extgwt and gwt)