Summary:
@public
This diff implements message passing between the `WKWebView` and React Native. As with `<WebView/>`, we can only send/receive strings.
**Usage:**
1. Set `messagingEnabled` to `true`.
1. To send data from the web view to React Native, call `postMessage(data)` within the web view. This forces React Native to execute the `onMessage` prop on the `WKWebView` component. `onMessage` will be called with an event `e`, where `e.nativeEvent.data` will be the data you passed into `postMessage`.
1. To send data from React Native to the web view, call `UIManager.dispatchViewManagerCommand` to dispatch the `UIManager.RCTWKWebView.Commands.postMessage` command. Look at [[ https://fburl.com/u1wusf2f | this part of the existing `<WebView/>` ]] component for more details. After you make the call, React Native will dispatch a `'message'` event to the `document` object within the webview. You can listen to the event by doing `document.addEventListener('message', callback)`. Let the event dispatched be `e`. Then, `e.data` is the data you sent over from React Native.
[[ P58627181 | This Playground.js ]] illustrates the usage.
Reviewed By: shergin
Differential Revision: D6304850
fbshipit-source-id: 29075ef753296e9fb5a9cddeb1ad0f4ff7e28650
Héctor Ramos
Ramanpreet Nara