Fetch-observable NPM

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();