Pegasus

Pegasus is a tiny lib that lets you load JSON data while loading other scripts.

If you have a static website, using this technique, you can reduce the time to display data. Works with any JS lib (React, Vue, jQuery, ...).

Before

JSON (yellow bar) is downloaded several milliseconds after the JS library (orange bar).

After (with Pegasus)

JSON (yellow bar) and the JS library (orange bar) are downloaded at the same time.

Install

Embedded (recommended)

To save a network call, it's recommended to simply paste the following code pegasus.min.js in your HTML page before other scripts.

CDN

https://unpkg.com/@typicode/pegasus/dist/pegasus.min.js

npm

$ npm install @typicode/pegasus

Please note that pegasus is available on npm under @typicode/pegasus

Demo

http://typicode.github.io/pegasus

Benchmark

Average time to display data on the demo site.

| | jQuery only | jQuery + Pegasus | |:------------|:-------------|:------------------| |EDGE | 3000 ms | 2100 ms | |3G | 860 ms | 640 ms | |DSL | 270 ms | 230 ms |

Note: jQuery is used for illustration only, you can use Pegasus with any other Javascript library.

Usage example

<!-- Load (or embed) Pegasus before loading any other script -->
<script src="pegasus.min.js"></script>

<!-- Make your request(s) -->
<script>
  var request = pegasus('http://api.example.com');
</script>

<!-- Load your app lib(s) -->
<script src="lib.js"></script>

<!-- Use .then() method to retrieve data in your app -->
<script>
  request.then(
    // success handler
    function(data, xhr) {
      // do something useful like
      $('#data').text(JSON.stringify(data));
    },
    // error handler (optional)
    function(data, xhr) {
      console.error(data, xhr.status)
    }
  );
</script>

Optionally, you can set a timeout using pegasus.timeout = milliseconds

Support

All modern browsers and IE9+

License

MIT - Typicode