Low level: Bookmarking and History support

[Marc Englund]

Component that corresponds to the browser back button

Provides server-side api for maintaining a list of caption+token pairs (history). Updates browser history to correspond to the server-side list, and triggers events (selected history item = token) as appropriate.

Make GWT history API accessible from server-side.

[Sami Ekblad]

It could be useful to take a look GWT API and implementation of this feature.

[Marc Englund]

Also remember bookmarking (!) support. This might actually be more often needed than backbutton. We could pass # to the server from the client; that is: window.open("#someid") changes the url, but does not reload the page; exactly what we want. But the server can not read the #someid when browsing to http://someurl#someid, so it's currently not usable for bookmarking. We could pass the #someid to the server in a uidl-request after the client has loaded though, in the first uidl request.

[Marc Englund]

A partial solution - these changes will make the hash (#) in the url go trough to the parameterHandler:

ApplicationConnection.java:

    public ApplicationConnection(WidgetSet widgetSet,
            ApplicationConfiguration cnf) {

        [...SNIPPED...]

        String hash = getLocationHash();
        makeUidlRequest("repaintAll=1"
                + (hash != null && hash.length() > 1 ? "&hash=" + hash : ""));
        applicationRunning = true;
    }

    /**
     * Get uri hash
     * 
     * @return the hash (fragment) part of the url
     */
    private native static String getLocationHash()
    /*-{
        
        return $doc.location.hash;
    }-*/;

CommunicationManager.java:232, before variable handling:

                // Handle parameters
                final Map parameters = request.getParameterMap();
                if (window != null && parameters != null) {
                    window.handleParameters(parameters);
                }

Note however that GWT history should also be in use before enabling this, otherwise the backbutton will cause problems.

[Jouni Koivuviita]

Upping this, since we could really, _very_ really, use this in our upcoming new feature browser. Any chances of getting it in 5.3.0?

[Matti Tahvonen]

Low level UriFragmentUtility? component committed in [5883].

It is just a simple invisible (0x0 sized) component so does not need any major API changes to core framework. With UriFragmentUtility? added to GUI developer can:

• read current uri fragment (part of uri after # character)
• set it (makes step into browsing history -> enables backbutton, changes url -> makes application state bookmarkable)
• listen to changes ( application can react to back/forward button clicks)

Minor inconvenience is that the initial fragment is not known at first render. If fragment is initially null on server side, client side will updated after first render (to "" if empty so listener will fire).

Later we might add features like a view framework or breadcrumb components that uses services provided by this component.