Question

I have a multipage application which needs to manually switched from one page to another. could it be done in GWT since it is targeted towards single page application. I am learning from the Google code and online forums but could not find any application which had multi-pages not linked by a common entry-point. Any ideas?

Answer 1

GWT has support for “pages” within application via URL fragment identifier (FI), i.e. http://www.yourhost.vom/main#pagename, where “pagename” is a fragment identifier representing a “page” within your app.

This “pages” (note that browser never really reloads the page, so GWT app stays the same), have full history support and are bookmarkable.

NOTE: throughout GWT docs fragment identifier is sometimes referred to as place token or history token.

1. Enable history support by adding an iframe to your host page:

   <iframe src="javascript:''" 
           id="__gwt_historyFrame" 
           style="width:0;height:0;border:0">
   </iframe>
   

2. Register a ValueChangeHandler to be notified when FI (page) changes: History.addValueChangeHandler(..). Within this handler you put a logic that displays the new page.

3. Go to a particular page by calling History.newItem("newpage") (without #)

4. You can even pass “parameters” to page, by dividing fragment identifier into sub parts: for example “#edit/user4”. Just parse this FI, invoke code that shows edit page and pass “user4” to it. You can use any character to divide FI into a “page” part and “parameter” part (I use “/” here). To see this in real life: open a message in gmail and look at URL.