get-js/lib/get.js

A lightweight library to asynchronously load scripts on the fly.

"use strict";

Object.defineProperty(exports, "__esModule", {
  value: true
});
exports["default"] = void 0;

var _util = require("./util");

var resolved = {};
/**
 * Load javascript url asynchronously.
 *
 * @param {*} url               The javascript url to load.
 * @param {*} callback          Callback function to invoke on success.
 * @param {*} errorCallback     Callback function to invoke on error.
 * @returns {void}
 */

function loadScript(url, callback, errorCallback) {
  var invokeCallback = function invokeCallback() {
    resolved[url] = true;

    if ((0, _util.isFunction)(callback)) {
      callback();
    }
  };

  if (resolved[url]) {
    invokeCallback();
    return;
  }

  var script = document.createElement('script');
  script.type = 'text/javascript';

  if (script.readyState) {
    // IE
    script.onreadystatechange = function () {
      if (script.readyState == 'loaded' || script.readyState == 'complete') {
        script.onreadystatechange = null;
        invokeCallback();
      }
    };
  } else {
    // Others
    script.onload = function () {
      invokeCallback();
    };
  }

  script.onerror = function (e) {
    resolved[url] = false;
    console.log('error', e);

    if ((0, _util.isFunction)(errorCallback)) {
      errorCallback();
    }
  };

  script.src = url;
  var parent = document.body || document.head || document;
  parent.appendChild(script);
}
/**
 * Load javascript url (or a list of urls) asynchronously
 * and return a Promise instance.
 *
 * @param {*} src
 * @param {*} opts
 * @returns {Promise}
 */


function get(src, opts) {
  if ((0, _util.isString)(src)) {
    return new Promise(function (resolve, reject) {
      loadScript(src, function () {
        return resolve(true);
      }, function () {
        return reject();
      });
    });
  } else if ((0, _util.isArray)(src)) {
    var p = Promise.resolve(true);
    src.forEach(function (url) {
      p = p.then(function () {
        return get(url);
      });
    });
    return p;
  }

  throw new Error('Invalid argument for get()');
}

var _default = get;
exports["default"] = _default;