react-async-poll

react-async-poll

WebSockets are cool and awesome, but sometimes we don't get to choose our backend. So how can we still get the most recent data into our react app on a regular basis? Polling to the rescue!

Installation

react-async-poll requires React 0.14 or later.

npm install --save react-async-poll

asyncPoll([intervalDuration], [onInterval])

Connects a React component to a polling instance.

Arguments

• [intervalDuration] (Number): If specified, this length of time in milliseconds will be used to determine how long to wait until the next call of the [onInterval] function once the returned promise resolves. The default value is 60000.
• [onInterval([ownProps], dispatch)] (Function): If a Promise is returned, [onInterval] will initiate a setTimeout with the [intervalDuration] once the Promise has resolved. The dispatch parameter is only passed to [onInterval] if it is available in props, otherwise it will be undefined.

Remarks

• The asyncPoll function needs to be invoked twice. The first time with the first two arguments described above (configuration), and a second time, with the last (the component): asyncPoll(intervalDuration, onInterval)(MyComponent). This is because a higher-order component is just a function that takes an existing component and returns another component that wraps it.

• It does not modify the passed React component. It returns a new, polling component, that you should use instead.

API Reference

Your component that is passed to asyncPoll is wrapped and passed its ownProps and an additional three that give you explicit control over the polling, if you have that use case.

Property	Type	Description
isPolling	boolean	whether or not there is a polling instance in the wrapper component
stopPolling	function	stops the polling in the wrapper component if not already stopped, handy if you want to stop the polling before it is done by default in componentWillUnmount
startPolling	function	starts the polling in the wrapper component if not already polling

Usage

// ES6
...
import React from 'react';
import asyncPoll from 'react-async-poll';

const WrappedComponent = ({ data }) => {
	const list = data.map(({ title }) => <li>{title}</li>);
	return <ul>{list}</ul>;
};

const onPollInterval = (props, dispatch) => {
	/*
	In this example, dispatch will return a Promise
	and then call this function again [intervalDuration]
	milliseconds later once the Promise has resolved
	*/
	return dispatch(getNewData(props.id));
};

/*
The first invocation of asyncPoll will return a function
that accepts only one argument: your component
*/
export default asyncPoll(60 * 1000, onPollInterval)(WrappedComponent);

Todo

• Add unit tests

License

MIT Licensed Copyright (c) Cameron Bourke 2016