react-native-webview/src/WebViewShared.ts

/**
 * Copyright (c) 2015-present, Facebook, Inc.
 *
 * This source code is licensed under the MIT license found in the
 * LICENSE file in the root directory of this source tree.
 *
 * @format
 * @flow
 */

import escapeStringRegexp from 'escape-string-regexp';
import { Linking } from 'react-native';
import {
  WebViewNavigationEvent,
  WebViewNavigation,
} from './types/WebViewTypes';

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

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

const originWhitelistToRegex = (originWhitelist: string): string =>
  escapeStringRegexp(originWhitelist).replace(/\\\*/g, '.*');

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

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

const createOnShouldStartLoadWithRequest = (
  loadRequest: (
    shouldStart: boolean,
    url: string,
    lockIdentifier?: number,
  ) => void,
  originWhitelist?: string[],
  onShouldStartLoadWithRequest?: (event: WebViewNavigation) => boolean,
) => ({ 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);
};

export {
  defaultOriginWhitelist,
  createOnShouldStartLoadWithRequest,
  originWhitelistToRegex,
};