[
https://issues.apache.org/jira/browse/WICKET-5588?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=15956830#comment-15956830
]
Daniel Stoch commented on WICKET-5588:
--------------------------------------
{quote}
1. Use the same websocket connection for ajax updates.
{quote}
Unfortunately it does not always work as expected and there are some
limitations in implementation.
So for now I am trying to go with this solution:
{quote}
2. Ordering responses (which requires solving such problems as: lost responses,
timeouts, maybe some kind of redelivery, etc...).
{quote}
So I want to add some ordering information (key-value) to responses for both
ajax and websocket. This information then will be read on client side (JS) to
handle proper processing order of responses. But I cannot find a good entry
point to add such generic information (order information should be calculated
in context of page/component). Any ideas how to add such information to
response in Wicket 6.x?
> Mixing Ajax and push (Atmosphere/native-websockets) updates does not respect
> order
> ----------------------------------------------------------------------------------
>
> Key: WICKET-5588
> URL: https://issues.apache.org/jira/browse/WICKET-5588
> Project: Wicket
> Issue Type: Improvement
> Components: wicket, wicket-atmosphere, wicket-native-websocket
> Affects Versions: 6.15.0, 6.21.0
> Reporter: Daniel Stoch
> Assignee: Emond Papegaaij
> Attachments: 5588-ajax-thru-websocket.tgz
>
>
> As far as I know in Wicket ajax calls by default using the same channel and
> they are queued. But in wicket-atmosphere integration on the client side the
> refreshing is done by calling (inside wicket-atomosphere.js):
> Wicket.Ajax.process(response.responseBody);
> It looks like Wicket.Ajax.process() function does not use channels
> management, so it can result in out-of-order response processing. This method
> was added to support Atmosphere push calls in Wicket. See the commit (for
> issue: WICKET-4668):
> https://github.com/apache/wicket/commit/130b063722e55510f2b2a3b47889e14210a5a32f
> *Example scenario to reproduce this problem:*
> When we try to refresh a component (panelA) via ajax when two different
> threads in the "same" time perform such refresh.
> 1. The first thread (thread1) is a standard servlet container thread to
> handle user request from a browser:
> - user clicks AjaxLink and on onClick method panelA is refreshed by
> target.add(panelA).
> 2. The second thread (thread2) is a notification from a backend system which
> causes a panelA refreshing too:
> - it can be done for eg. using Atmosphere integration by EventBus.post() -
> panelA is refreshed by target.add(panelA) too.
> On the server side only one thread can access a page at a time so everything
> is "queued" properly: the thread1 panelA refresh is executed, then the
> thread2 refresh code is fired.
> But it looks like on the client side the order of ajax calls is undefined:
> sometimes JS code added from the thread1 is executed as first, sometimes as a
> second one. On my computer this order almost always is wrong. It leads to an
> incorrect situation when the component state on a server is different than
> the DOM tree on the client browser (so for example user can clicks not
> existing link).
--
This message was sent by Atlassian JIRA
(v6.3.15#6346)
