[jira] [Updated] (CB-10774) CDVUIWebView performs javascript synchronous, but command queue expects it to be async

["Torsten Freyhall (JIRA)" <ji...@apache.org>]

     [ https://issues.apache.org/jira/browse/CB-10774?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel ]

Torsten Freyhall updated CB-10774:
----------------------------------
    Labels: cordova-ios-4.1.0  (was: )

> CDVUIWebView performs javascript synchronous, but command queue expects it to be async
> --------------------------------------------------------------------------------------
>
>                 Key: CB-10774
>                 URL: https://issues.apache.org/jira/browse/CB-10774
>             Project: Apache Cordova
>          Issue Type: Bug
>          Components: iOS
>    Affects Versions: 4.1.0
>            Reporter: Torsten Freyhall
>              Labels: cordova-ios-4.1.0
>
> From https://issues.apache.org/jira/browse/CB-10530 regarding app freezing at launch.
> ...
> However I was not sure about why the timer resolves due to long script execution times though. It seems like the intention is that whenever gap://ready is loaded in the iframe, the immediate response from the native side should be to call nativeFetchMessages() which should clear the timeout.
> Therefore I dug a little deeper in the native side, and found that the evaluateJavaScript:completionHandler: in CDVCommandQueue expects implementation to to be async (a comment in the code says so), but the CDVUIWebViewEngine method actually is implemented synchronous.
> I wrapped the entire method in a dispatch_async call (maybe a very naive solution, it might mess with references?):
> dispatch_async(dispatch_get_main_queue(), ^{
>   NSString* ret = [(UIWebView*)_engineWebView stringByEvaluatingJavaScriptFromString:javaScriptString];
> if (completionHandler)
> { completionHandler(ret, nil); }
> });
> This also solves the original issue on cordova-ios 4.0.1 as the timeout never resolves, so maybe asyncing this method should also be a part of the proper fix?



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

---------------------------------------------------------------------
To unsubscribe, e-mail: issues-unsubscribe@cordova.apache.org
For additional commands, e-mail: issues-help@cordova.apache.org