I am making an app in GWT. It is like a dashboard and will have out of the widgets.
Now when we ship this out, there is a use case that the customer might want to create their own GWT widget and use this in the dashboard app.
As I understand it, they will not be able to do this since we cannot ship our source code which is needed to compile the whole app again once tag of their widget/module gets into the gwt.xml file of my app.
I cannot use anything other that GWT to make this dashboard. And their widget could be say a flash heapmap, a jquery widget/plugin, another GWT module, a jsp page that renders a visualization from back end.
So far my thoughts have been to provide a widget in my app which is a wrapper in the form of an Iframe and call their main page (they will provide url), and have an api to let my app and their widget talk.
But I would like to know if there are other / better approaches?
Depending on how closed source your application is (can custom JS/HTML be added to pages?), you could always provide a native Javascript (JSNI) API for some custom dashboard widgets. The simplest solution I'm thinking of would be a JSNI method which your customers could call to set the HTML content of said widget. This method would allow them to use a variety of options such as JQuery widgets, their own GWT widget generated HTML or even an IFrame pointing to their JSP pages etc... You could then provide additional JSNI API methods which would allow them to interact with your app/widget in other ways as well. This would be better than the IFrame method because you wouldn't have to deal with cross domain scripting security issues.