react-native-webview/src/WebViewShared.ts

import escapeStringRegexp from 'escape-string-regexp';
import { Linking, UIManager as NotTypedUIManager } from 'react-native';
import {
  WebViewNavigationEvent,
  OnShouldStartLoadWithRequest,
  CustomUIManager,
} from './WebViewTypes';

const UIManager = NotTypedUIManager as CustomUIManager;

const defaultOriginWhitelist = ['http://*', 'https://*'];

const extractOrigin = (url: string): string => {
  const result = /^[A-Za-z][A-Za-z0-9+\-.]+:(\/\/)?[^/]*/.exec(url);
  return result === null ? '' : result[0];
};

const originWhitelistToRegex = (originWhitelist: string): string =>
  `^${escapeStringRegexp(originWhitelist).replace(/\\\*/g, '.*')}`;

const passesWhitelist = (
  compiledWhitelist: ReadonlyArray<string>,
  url: string,
) => {
  const origin = extractOrigin(url);
  return compiledWhitelist.some(x => new RegExp(x).test(origin));
};

const compileWhitelist = (
  originWhitelist: ReadonlyArray<string>,
): ReadonlyArray<string> =>
  ['about:blank', ...(originWhitelist || [])].map(originWhitelistToRegex);

const createOnShouldStartLoadWithRequest = (
  loadRequest: (
    shouldStart: boolean,
    url: string,
    lockIdentifier: number,
  ) => void,
  originWhitelist: ReadonlyArray<string>,
  onShouldStartLoadWithRequest?: OnShouldStartLoadWithRequest,
) => {
  return ({ nativeEvent }: WebViewNavigationEvent) => {
    let shouldStart = true;
    const { url, lockIdentifier } = nativeEvent;

    if (!passesWhitelist(compileWhitelist(originWhitelist), url)) {
      Linking.openURL(url);
      shouldStart = false;
    }

    if (onShouldStartLoadWithRequest) {
      shouldStart = onShouldStartLoadWithRequest(nativeEvent);
    }

    loadRequest(shouldStart, url, lockIdentifier);
  };
};

const getViewManagerConfig = (
  viewManagerName: 'RNCUIWebView' | 'RNCWKWebView' | 'RNCWebView',
) => {
  if (!UIManager.getViewManagerConfig) {
    return UIManager[viewManagerName];
  }
  return UIManager.getViewManagerConfig(viewManagerName);
};

export {
  defaultOriginWhitelist,
  createOnShouldStartLoadWithRequest,
  getViewManagerConfig,
};