README.md

PulltoRefresh.js • Demos

A small, but powerful Javascript library crafted to power your webapp's pull to refresh feature. No markup needed, highly customizable and dependency-free!

---

Donations

If you found this project useful, please consider making a donation.

Installation

Download PulltoRefresh either from the NPM Registry, CDNJS or UNPKG:

$ npm install pulltorefreshjs --save-dev
$ wget -O pulltorefresh.js https://unpkg.com/pulltorefreshjs

Include the JS file in your webapp and initialize it:

const ptr = PullToRefresh.init({
  mainElement: 'body',
  onRefresh() {
    window.location.reload();
  }
});

Bundlers can consume pulltorefreshjs as CommonJS and ES6-modules syntax:

import PullToRefresh from 'pulltorefreshjs';
// or
const PullToRefresh = require('pulltorefreshjs');

API

• init(options) Will return a unique ptr-instance with a destroy() method.
• destroyAll() Stop and remove all registered ptr-instances.
• setPassiveMode(isPassive) Enable or disable passive mode for event handlers (new instances only).

Options

• distThreshold (integer) Minimum distance required to trigger the refresh.
  — Defaults to 60
• distMax (integer) Maximum distance possible for the element.
  — Defaults to 80
• distReload (integer) After the distThreshold is reached and released, the element will have this height.
  — Defaults to 50
• distIgnore (integer) After which distance should we start pulling?
  — Defaults to 0
• mainElement (string) Before which element the pull to refresh elements will be?
  — Defaults to body
• triggerElement (string) Which element should trigger the pull to refresh?
  — Defaults to body
• ptrElement (string) Which class will the main element have?
  — Defaults to .ptr
• classPrefix (string) Which class prefix for the elements?
  — Defaults to ptr--
• cssProp (string) Which property will be used to calculate the element's proportions?
  — Defaults to min-height
• iconArrow (string) The icon for both instructionsPullToRefresh and instructionsReleaseToRefresh
  — Defaults to ⇣
• iconRefreshing (string) The icon when the refresh is in progress.
  — Defaults to …
• instructionsPullToRefresh (string) The initial instructions string.
  — Defaults to Pull down to refresh
• instructionsReleaseToRefresh (string) The instructions string when the distThreshold has been reached.
  — Defaults to Release to refresh
• instructionsRefreshing (string) The refreshing text.
  — Defaults to Refreshing
• refreshTimeout (integer) The delay, in milliseconds before the onRefresh is triggered.
  — Defaults to 500
• getMarkup (function) It returns the default HTML for the widget, __PREFIX__ is replaced.
  — See src/lib/markup.js
• getStyles (function) It returns the default CSS for the widget, __PREFIX__ is replaced.
  — See src/lib/styles.js
• onInit (function) The initialize function.
• onRefresh (function) What will the pull to refresh trigger? You can return a promise.
  — Defaults to window.location.reload()
• resistanceFunction (function) The resistance function, accepts one parameter, must return a number, capping at 1.
  — Defaults to t => Math.min(1, t / 2.5)
• shouldPullToRefresh (function) Which condition should be met for pullToRefresh to trigger?
  — Defaults to !window.scrollY • Please note that this default is useful whenever you're setting mainElement as the body of the document, if you need it in another element with overflow, use !this.mainElement.scrollTop. Refer to the multiple instances demo for reference.

Use with React

With ReactDOMServer and renderToString() you can use components as icons instead of just strings. In this example we also use Font Awesome to get nice icons with animation, but you can use any React component you like.

Demo on codesandbox.io

import React, { Component } from 'react';
import ReactDOMServer from 'react-dom/server';
import PullToRefresh from 'pulltorefreshjs';
import { faSyncAlt} from '@fortawesome/free-solid-svg-icons';
import { FontAwesomeIcon } from '@fortawesome/react-fontawesome';

class App extends Component
{
    componentDidMount()
    {
        PullToRefresh.init({
            mainElement: 'body',
            onRefresh() {
                window.location.reload();
            },
            iconArrow: ReactDOMServer.renderToString(
                <FontAwesomeIcon icon={faSyncAlt} />
            ),
            iconRefreshing: ReactDOMServer.renderToString(
                <FontAwesomeIcon icon={faSyncAlt} spin={true} />
            ),
        });
    }

    componentWillUnmount()
    {
        // Don't forget to destroy all instances on unmout
        // or you will get some glitches.
        PullToRefresh.destroyAll();
    }

    render()
    {
        return (
            <div>
                <h1>App</h1>
            </div>
        );
    }
}

export default App;

Contribute

To quickly start the development workflow:

1. Install NodeJS (NVM)
2. Run nvm use 10 && npm install
3. Then npm run dev

This will watch and compile the bundle for browser usage.

E2E tests are executed with Testcafé.

• Run npm test to fire tests in the default browser, use BROWSER to change this
• ...or just run make to setup the dependencies and run tests only (e.g. CI)

Advanced debug can be achieved with testcafe-live, e.g.

$ npm test --live chrome tests/e2e/cases --debug-on-fail

Roadmap

• More events: onPullStart, onPullDown(direction, willRefresh), onRelease(willRefresh)
• Fully customizable CSS
• Gallery of use cases
• Advanced demos
• Tests
• Minified releases