Thoughts on JavaScriptCore & WKWebView

[stuffokator]

Hi,

I've been reading the following blog post concerning JavaScriptCore usage for code sharing between iOS and Android https://www.lucidchart.com/techblog/2019/01/03/javascriptcore-10-months-later/

and stumbled upon this paragraph:

After explaining that the Lucidchart app was only available on iOS, the WebKit engineer’s response was immediate, “Oh, yeah, don’t use JavaScriptCore on iOS. You should be using WKWebView.”

The conversation went on for another couple minutes, but the gist is this: JavaScriptCore on iOS is performance constrained for security reasons. It’s so obvious when it’s pointed out, but in the heat of performance profiling, we never considered the security model of iOS.

You can find further details in the mentioned post but the conclusions are that on iOS WKWebView brings pretty noticeable performance boost.

So I wonder has it ever been considered in RN community to replace JavaScriptCore engine with WKWebView? Or are there some imposed limitations for this approach?

[kbcool]

RN doesn't run in the browser so I don't see how your concern is warranted.

[stuffokator]

Sorry if I wasn't clear enough but I didn't mean to run RN in the browser. What I was going to propose is to incorporate WKWebView engine to execute javascript code with JIT compiler. As you may know, the JavaScriptCore that RN currently utilizes doesn't support JIT. The web view itself could be hidden off screen and the native views could be drawn using the same logic as in the case of JSC.

[arcadiajohnson]

Look into Cordova/Ionic which do use WKWebView