Example for PR facebook/react-native#10946 (comment)

Important files

Javascript implementation:

• CustomWebView.js

Usage from JS:

• app.js

Android implementation:

• CustomWebViewManager.java
  • This file contains all the logic for the custom webview. In this case all I do is extend the ReactWebViewClient and override shouldOverrideUrlLoading which lets me hook into URL navigations. Dispatches onSomethingHappened event if URL contains a certain string.
• CustomWebViewManagerPackager.java
  • The packager-class, used in MainApplication to hook up the above ViewManager to the app.

iOS implementation:

• RCTCustomWebView.h
  • Header-file for the webview
• RCTCustomWebView.m
  • Same logic as Android. Overriding shouldStartLoadWithRequest to hook into URL navigation. Dispatches onSomethingHappened event if URL contains a certain string.
• RCTCustomWebViewManager.h
  • Header-file for view manager
• RCTCustomWebViewManager.m
  • This is basically a copy-paste of RN's RCTWebViewManager. The only differences (noted in the file comments) is:
    1. Imports at the top
    2. The WebView returned (have to use the custom RCTCustomWebView of course)
    3. We also have to export the onSomethingHappened view property
• RCTWebView+Custom.h
  • Adding a category to RCTWebView so we can expose (& call) shouldStartLoadWithRequest from (the child-cass) RCTCustomWebView. Not really important to this example, but good to note.