WKWebView script message handlers not called on physical devices

Originator:yannick.loriot
Number:rdar://18512488 Date Originated:
Status:Open Resolved:
Product:iOS SDK Product Version:
Classification:Serious Bug Reproducible:Always
 
Summary:
I have a small javascript which triggers some events via the webkit.messageHandlers property and the WKWebView which is listening to this events.
On the simulator everything is ok, but on the device I received no events expect if I add the webview as subview of another one.

Steps to Reproduce:
1. Create a small html page with a javascript which trigger an event
2. Create a WKWebViewConfiguration and add an handler for the event
3. Create the WKWebView and wait for the event
(See gist: https://gist.github.com/YannickL/4a3a11073d3cedf7e7ec)

Expected Results:
I would received the event triggered by my script

Actual Results:
There is nothing on the device (everything is ok on the simulator) expect if I put the webview as subview

Version:
iOS 8.0.2

Notes:
I would use the WKWebView to be able to work with websocket so I don't need to add the webview as subview. I just need to use the webkit engine.

Configuration:
iPad Mini Retina

Comments

Workaround

We've discovered a workaround:

Only call your Javascript's initial function in window.onload, and make sure you've added the WKWebView as a subview somewhere, even if it's 0-width/height. UIApplication.sharedApplication.delegate.window.addSubview(webView) works fine

By patrick at July 17, 2015, 11:37 p.m. (reply...)

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