GWT inter project communication

Question

Hi, We have a large GWT project and many smaller GWT sub-projects basically the large controller project invokes the smaller projects via many means such as some are incorporated into iframes that are shown in page, some are shown by clicking a URL and opening the project into a new window.

The requirement is to change the Css on the fly, this is possible in the main project, by simply changing, on the fly, the href of the link tag containing stylesheet url

is it possible to propogate this change to the sub-projects too ? or asking in more broader terms, how do i achieve inter - project communication in GWT ?

Answer 1

A browse allows you to call Javascript code across IFrames if the domains of the different GWT applications are the same.

Using JSNI you can register methods on the window object which call back into the GWT application and using JSNI the other project can invoke this method.

Answer 2

If all the apps are served from the same domain you could store the name of the stylesheet in a cookie. Each app would then use the cookie to select the appropriate stylesheet.

String theme = Cookies.getCookie("THEME");
if (theme == null) {
    theme = "default";
}

Element e = DOM.createElement("link");
DOM.setElementProperty(e, "rel", "stylesheet");
DOM.setElementProperty(e, "href", GWT.getModuleBaseURL() + currentTheme + 
    ".css");
DOM.appendChild(getHead(), e);

private native Element getHead() /*-{
    return $doc.getElementsByTagName('head')[0];
}-*/;