fetch-observable

Observable-based Fetch API

Usage no npm install needed!

<script type="module">
  import fetchObservable from 'https://cdn.skypack.dev/fetch-observable';
</script>

README

fetchObservable()

Observable-based Fetch API that automatically refreshes data and notifies subscribers.

Features

  • Uses the standard Fetch API.
  • Uses Observable syntax from ES Observable proposal.
  • Runs in Node and browsers. (BYO Fetch API and Promises polyfills though)

Installation

    npm install --save fetch-observable

Usage

import fetchObservable from "fetch-observable";

// Creates a single observable for one or multiple URLs.
const liveFeed = fetchObservable(
    "http://example.org/live-feed.json", // <-- URL or array of URLs.
    {
        fetch: fetch,  // <-- Replacable fetch implementation.
        refreshDelay: (iteration) => iteration * 1000, // <-- Callback or just integer ms.
        method: "POST" // <-- Basic Fetch API options.
    }
).map((response) => response.json()); // map() resolves Promises.

// Subscribe-syntax of ES Observables activates the observable.
const subscription1 = liveFeed.subscribe({
    next (response) {
        console.dir(response.json());
    },
    error (error) {
        console.warn(error.stack || error);
    }
});

// Multiple subscriptions allowed. They all get the result.
const subscription2 = liveFeed.subscribe({next () {}});

// Observable can be paused and resumed manually.
liveFeed.pause();
liveFeed.resume();

// Observable will be paused automatically when no subscriptions left.
subscription1.unsubscribe();
subscription2.unsubscribe();

Community

Let's start one together! After you ★Star this project, follow me @Rygu on Twitter.

License

BSD 3-Clause license. Copyright © 2015, Rick Wong. All rights reserved.