[jira] [Commented] (TAP5-1854) AjaxComponentEventRequestHandler doesn't handle the case where a response has already be returned, and may append an empty JSON Object to the response

["khalil haddad (JIRA)" <ji...@apache.org>]

    [ https://issues.apache.org/jira/browse/TAP5-1854?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=14258329#comment-14258329 ] 

khalil haddad commented on TAP5-1854:
-------------------------------------

Hello,
I think this issue has to be reopened. I'm running on this configuration :
- Tapestry 5.3.7
- Tapestry5-jQuery 3.3.7
- WAS 8.5
- IBM J9 VM (build 2.6, JRE 1.7.0 AIX ppc64-64 Compressed References 20141013_217026)

When I try to access to a page which includes a jQuery datatable, I have systematically the same error :
"DataTables warning: JSON data from server could not be parsed. This is caused by a JSON formatting error."

If I inspect the JSON data received from the server, I notice that an empty JSON {} is added at the end of the data like in the issue #TAPESTRY-2619 .

The same application works fine on Tomcat 7.

> AjaxComponentEventRequestHandler doesn't handle the case where a response has already be returned, and may append an empty JSON Object to the response
> ------------------------------------------------------------------------------------------------------------------------------------------------------
>
>                 Key: TAP5-1854
>                 URL: https://issues.apache.org/jira/browse/TAP5-1854
>             Project: Tapestry 5
>          Issue Type: Bug
>          Components: tapestry-core
>         Environment: WebSphere on linux, and Jetty on osx
>            Reporter: Kai Lilleby
>            Assignee: Howard M. Lewis Ship
>            Priority: Blocker
>             Fix For: 5.3.3, 5.4
>
>
> In committ 1155178 the removal of "if (resultProcessorInvoked.get()) return" seems to have reintroduced an old issue (#TAPESTRY-2619).
> When running on a Servlet engine that does not honor HttpResponse.getOutputStream().close() - i.e. subsequent writing to the responses outputstream will be written to the client - which is true for WebSphere but not for Jetty, the final line in AjaxComponentEventRequestHandler will write an new jsonobject to the response, resulting in an invalid json structure. 
> My guess would be that the following block of code:
> -------------
>         if ((!resultProcessorInvoked.get()) && queue.isPartialRenderInitialized())
>         {
>             partialRenderer.renderPartialPageMarkup();
>             return;
>         }
>         // Send an empty JSON reply if no value was returned from the component event handler method.
>         // This is the typical behavior when an Ajax component event handler returns null.
>         JSONObject reply = new JSONObject();
>         resultProcessor.processResultValue(reply);
> }
> ---------------
> should be replaced with:
> --------------- 
>        if ((!resultProcessorInvoked.get()) && queue.isPartialRenderInitialized())
>         {
>             partialRenderer.renderPartialPageMarkup();
>             return;
>         }
>        // If the result processor was passed a value, then it will already have rendered, and there is nothing more to do.
>        if (resultProcessorInvoked.get()) return;
>        
>         // Send an empty JSON reply if no value was returned from the component event handler method.
>         // This is the typical behavior when an Ajax component event handler returns null.
>         JSONObject reply = new JSONObject();
>         resultProcessor.processResultValue(reply);
> }
> ------------------



--
This message was sent by Atlassian JIRA
(v6.3.4#6332)