[CB-8838] WKWebView iosExec Results in Double Call

• Type: Sub-task
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 4.0.0
• Fix Version/s: 4.0.0
• Component/s: cordova-ios, cordova-js, cordova-lib
• Assignee: Shazron Abdullah
• Reporter: Thomas Mouton
• Created: 09/Apr/15 22:12
• Updated: 23/Aug/18 06:52
• Resolved: 20/Apr/15 23:48

Description

When we invoke the cordova Barcode plugin, it is always called twice!

I have only looked at the code a short time, but it appears to me that:

• the first call to Barcode happens, and in iosExec, it gets placed in commandQueue.
• the first call passes to Objective C world by WKScriptMessageHandler - (void)userContentController:(WKUserContentController*)userContentController didReceiveScriptMessage:(WKScriptMessage*)message
• this call to Barcode does its thing, completes, and it's javascript response handler code winds through:
  CDVCommandDelegateImpl::sendPluginResult
  CDVCommandDelegateImpl::evalJSHelper
  CDVCommandDelegateImpl::evalJSHelper2
• in Helper2, the callback is finally passed to a webViewEngine, which processes the Javascript, and returns, on completion, a list of commands remaining in the javascript commandQueue.
• these commands are queued on the Obj-C side and run in CDVCommandQueue fashion.

AHA!

• since the command was persisted in commandQueue before execution, and not removed, it is called again!

SO

I moved the enqueue behavior into the branch that excludes bridgeMode === jsToNativeModes.WK_WEBVIEW_BINDING
This fixes it, but I am not confident its the right solution.

Do you have any insight into this problem?
Feedback for my solution?
A broader or more appropriate venue for the conversation?

Thanks!
Alex Mouton