:watch: React Interval Hook

React hook for using self-correcting setInterval, augmented by management methods (start, stop, isActive)

• Self-correcting (explanation)
• Manageable (start, stop, isActive)
• Thoroughly tested

Install

yarn add react-interval-hook

or

npm install --save react-interval-hook

Basic Usage

import React from 'react';
import { useInterval } from 'react-interval-hook';

const Example = () => {
    useInterval(() => {
        console.log('I am called every second');
    });
};

Advanced usage

Hook can accept various config option as well as return methods that allow you to control it behaviour.

Definition

useInterval(callback [, intervalMs] [, options]): { start, stop, isActive }

Example

import React, { useState } from 'react';
import { useInterval } from 'react-interval-hook';

const AdvancedExample = () => {
    const { start, stop, isActive } = useInterval(
        () => {
            console.log('Callback every 500 ms');
        },
        500,
        {
            autoStart: false,
            immediate: false,
            selfCorrecting: false,
            onFinish: () => {
                console.log('Callback when timer is stopped');
            },
        }
    );
    const [active, setActive] = useState(isActive());
    const [triggerFinishCallback, setTriggerFinishCallback] = useState(true);

    return (
        <div>
            <button type="button" onClick={start} id="start">
                Start
            </button>
            <button type="button" onClick={() => stop(triggerFinishCallback)} id="stop">
                Stop
            </button>
            <button type="button" onClick={() => setActive(isActive())} id="checkActive">
                Check active
            </button>
            <div id="active">Active: {active ? 1 : 0}</div>
            <div>
                <label htmlFor="trigger-finish-callback">
                    <input
                        id="trigger-finish-callback"
                        type="checkbox"
                        defaultChecked={triggerFinishCallback}
                        onChange={() => setTriggerFinishCallback(current => !current)}
                    />
                    Trigger finish callback
                </label>
            </div>
        </div>
    );
};

Usage For React Class Based Components

Quickstart

Start counting on render

import { ReactInterval } from 'react-interval';

const App = React.createClass({
  getInitialState() {
    return {count: 0};
  },

  render() {
    const {count} = this.state;

    return (
      <div>
        {count}
        <ReactInterval timeout={1000} enabled={true}
          callback={() => this.setState({count: this.state.count + 1})} />
      </div>
    );
  }
});

Full example

Change timeout on the fly, start and stop counting

import React from 'react';
import ReactDOM from 'react-dom';
import { ReactInterval } from 'react-interval';

const App = React.createClass({
  getInitialState() {
    return {
      enabled: false,
      timeout: 1000,
      count: 0
    };
  },

  render() {
    const {timeout, enabled, count} = this.state;

    return (
      <div>
        <ReactInterval {...{timeout, enabled}}
          callback={() => this.setState({count: this.state.count + 1})} />

        <input type="number" step="200" min="200" max="5000" value={this.state.timeout}
          onChange={({target: {value}}) => this.setState({timeout: parseInt(value, 10)})} />&nbsp;

        <button disabled={enabled} onClick={() => this.setState({enabled: true})}>
          Start</button>&nbsp;

        <button disabled={!enabled} onClick={() => this.setState({enabled: false})}>
          Stop</button>&nbsp;

        {count}
      </div>
    );
  }
});

const appRoot = document.createElement('div');
document.body.appendChild(appRoot);
ReactDOM.render(<App />, appRoot);

Options

callback: PropTypes.func.isRequired

Function repeatedly called after timeout

enabled: PropTypes.bool (default: false)

Should start timer?

timeout: PropTypes.number (default: 1000)

Timeout before each callback call

Options

| Name | Type | Default | Description | | ----------- | :------: | :------: | --------------------------------------------------------------------------------------------------------------------------------------------------------------------- | | autoStart | boolean | true | Start interval timer right after component is mounted | | immediate | boolean | false | Trigger callback immediately after timer is started | | selfCorrecting | boolean | true | Self correct time intervals between subsequent callback invocations to reflect actual time elapsed (setInterval and setTimeout are not accurate and tend to drift). | | onFinish | Function | () => {} | Called after timer is stopped (by stop method or component unmount) |

Management methods

useInterval hook return object with various management methods

| Name | Arguments | Return | Description | | -------- | ----------------------------------------------------------------------------- | :-----: | -------------------------------------------------------------------------------------------------- | | start | None | void | Starts timer when autoStart is set to false or after timer was stopped using stop method | | stop | [optional] triggerFinishCallback- Type: boolean- Default: true | void | Stops timer (not pause) after it was started using either autoStart option or start method | | isActive | None | boolean | Return current timer status - is it running or not |

License

MIT © minwork