[jsr372-experts] Re: Use clientId instead of channel name in jsf.push.open(...) and jsf.push.close(...)

From: Bauke Scholtz <balusc_at_gmail.com>
Date: Thu, 27 Oct 2016 10:09:15 +0200


ClientID works indeed better in case of namespaced views.

Cheers, B

On Fri, Oct 21, 2016 at 5:33 AM, Leonardo Uribe <leonardo.uribe_at_irian.at>

> Hi
> Following the review of websocket API, I have found there are 3 new
> javascript
> methods:
> jsf.push.init(...)
> jsf.push.open(channel)
> jsf.push.close(channel)
> The first one was already discussed in a previous email, but the remaining
> two
> suggest developers can only use one f:websocket declaration per channel
> in a view.
> This is a severe restriction that limits code reuse. Imagine this example:
> <f:websocket channel="refresh" ...>
> <f:ajax event="updatePanelA"/>
> </f:websocket>
> And in other section of the same view there is something like this:
> <f:websocket channel="refresh" ...>
> <f:ajax event="updatePanelB"/>
> </f:websocket>
> The idea is both declarations can share the same channel, but both have
> different purposes. Since both channels are connected automatically,
> it is only necessary to create one websocket connection per view.
> What I mean is the channel name is a logical pointer that can have multiple
> "receivers", even in the same view. f:websocket must be smart enough to
> detect when two components are sharing the same channel (if the channel
> token is equals for both jsf.push.init(...) scripts, it is fine to share
> it). If "connected" is set to false, you can just generate another
> channel token in the Renderer to isolate the session, and in that way you
> could have two or more websocket connections for the same channel
> in a view.
> If jsf.push.open(channel) and jsf.push.close(channel) use the channel
> name, it is not possible to identify which websocket connection must be
> opened or closed under the previous reasoning. So, I would like propose
> that jsf.push.open(...) and jsf.push.close(...) use the clientId
> instead, because it has more sense in that way and it allows more
> flexibility to do so. It also raise the question if we should create
> f:wsopen and f:wsclose client behavior tags to wrap there two javascript
> methods and bound them to buttons and other jsf components more easily.
> Another possible concept that support use the clientId is just render
> an invisible "div" panel for each f:websocket declaration in the
> place the component is located like this:
> <div id="mainForm:j_id_p" style="display:none"></div>
> If jsf.push.init(...) pass the clientId, it is possible to include
> a check for this panel in the DOM tree. If the panel exists then process
> the functions associated with the component, otherwise ignore or
> close automatically the websocket connection. If there is a section in
> the view that has been removed using f:ajax and that section has a
> f:websocket declaration then this code will detect the change and
> avoid further processing. This will ensure consistency between
> f:websocket and f:ajax.
> regards,
> Leonardo Uribe