To help you get started, we've collected the most common ways that promise-polyfill is being used within popular public projects.

gragland / react-component-data / src / resolveRecursive.js View on Github

function getDataFromTree(rootElement, rootContext, fetchRoot, mergeProps, isTopLevel){

  //console.log(`Now searching element (${rootElement.type.name || rootElement.type.displayName}):`, rootElement);

  // Get array of queries (fetchData promises) from tree
  // This will traverse down recursively looking for fetchData() methods
  let queries = getQueriesFromTree(rootElement, rootContext, fetchRoot, mergeProps);

  // No queries found. We're done!
  if (!queries.length) {
    return Promise.resolve();
  }

  // We've traversed down as far as possible in thecurrent tree branch ...
  // Wait on each query that we found, re-rendering the subtree when it's done.
  const mappedQueries = queries.map(({ query, element, context }) =>  {
    return query.then((newProps) => {
      const displayName = element.type.displayName;

      if (!displayName){
        // TODO: Use Promise.reject and catch()
        throw new Error('[React Component Data] When resolving component data recursively each component must have a displayName set.');
      }

      // Add to finalData array that will be returned
      finalData[displayName] = newProps;
      // Traverse children

View more ways to use promise-polyfill

Promise Polyfill

Lightweight ES6 Promise polyfill for the browser and node. Adheres closely to the spec. It is a perfect polyfill IE or any other browser that does not support native promises.

For API information about Promises, please check out this article HTML5Rocks article.

It is extremely lightweight. < 1kb Gzipped

Browser Support

IE8+, Chrome, Firefox, IOS 4+, Safari 5+, Opera

NPM Use

npm install promise-polyfill --save-exact

Bower Use

bower install promise-polyfill

CDN Polyfill Use

This will set a global Promise object if the browser doesn't already have window.Promise.

Downloads

• Promise
• Promise-min

Simple use

If you would like to add a global Promise object (Node or Browser) if native Promise doesn't exist (polyfill Promise). Use the method below. This is useful if you are building a website and want to support older browsers. Javascript library authors should NOT use this method.

import 'promise-polyfill/src/polyfill';

If you would like to not affect the global environment (sometimes known as a ponyfill, you can import the base module. This is nice for library authors or people working in environment where you don't want to affect the global environment.

import Promise from 'promise-polyfill';

If using require with Webpack 2+ (rare), you need to specify the default import

var Promise = require('promise-polyfill').default;

then you can use like normal Promises

var prom = new Promise(function(resolve, reject) {
  // do a thing, possibly async, then…

  if (/* everything turned out fine */) {
    resolve("Stuff worked!");
  }  else {
    reject(new Error("It broke"));
  }
});

prom.then(function(result) {
  // Do something when async done
});

Performance

By default promise-polyfill uses setImmediate, but falls back to setTimeout for executing asynchronously. If a browser does not support setImmediate (IE/Edge are the only browsers with setImmediate), you may see performance issues. Use a setImmediate polyfill to fix this issue. setAsap or setImmediate work well.

If you polyfill window.setImmediate or use Promise._immediateFn = yourImmediateFn it will be used instead of window.setTimeout

npm install setasap --save

import Promise from 'promise-polyfill/src/polyfill';
import setAsap from 'setasap';
Promise._immediateFn = setAsap;

Unhandled Rejections

promise-polyfill will warn you about possibly unhandled rejections. It will show a console warning if a Promise is rejected, but no .catch is used. You can change this behavior by doing.

-NOTE: This only works on promise-polyfill Promises. Native Promises do not support this function

Promise._unhandledRejectionFn = ;

If you would like to disable unhandled rejection messages. Use a noop like below.

Promise._unhandledRejectionFn = function(rejectError) {};

Testing

npm install
npm test

License

MIT