React iScroll

React component for wrapping iScroll library.

! Breaking changes in version 1.0.0

• Property for passing iScroll instance is renamed from iscroll to iScroll and naming is unified across whole package
  • use it like <ReactIScroll iScroll={iScroll}> instead of <ReactIScroll iscroll={iScroll}>
• Inner content wrapper is removed. https://github.com/schovi/react-iscroll/commit/ecd75bb75667a45d2e14a2eda0a1b7d56c9d54f4
  • You can do it by yourself by wrapping childrens of ReactIScroll component into one more div with specific styling (check Horizontal scroll example there in README)
  • Main iScroll element has same behaviour and you can still change styling with style and className properties.

What is iScroll?

iScroll is a high performance, small footprint, dependency free, multi-platform javascript scroller.

-- iScroll's homepage

Works on mobile and desktop, supports zooming, pagging, parallax scrolling, carousels and is incredibly small (4kb compress gzipped).

Why React component?

React components are a great way to compose your application. And they are a great way to handle third party libraries. You can wrap complex logic around a library and expose a simple API, which react users are used to.

Install

npm install react-iscroll

Usage

Simple example app. Allow scrolling on long list and catch event when scrolling starts.

var React = require('react'),
    ReactIScroll = require('react-iscroll'),
    iScroll = require('iscroll');

var ExampleApp = React.createClass({
  getDefaultProps: function() {
    return ({
      options: {
        mouseWheel: true,
        scrollbars: true
      }
    })
  },
  onScrollStart: function() {
    console.log("iScroll starts scrolling")
  },
  render: function() {
    var i = 0, len = 1000, listOfLi = [];

    for(i; i < len; i++) {
      listOfLi.push(<li key={i}>Row {i+1}</li>)
    }

    return (
      <div style={height: '100vh'}>
        <h1>Example of scrollable list</h1>
        <ReactIScroll iScroll={iScroll}
                      options={this.props.options}
                      onScrollStart={this.onScrollStart}>
          <ul>
            {listOfLi}
          </ul>
        </ReactIScroll>
      </div>
    )
  }
})

FAQs

onScroll event does not works

You have to use probe version of iScroll and add probeType to <ReactIScroll options={{probeType:2}}>. Check iScroll documentation for more information.

Configuration (API)

Basic configuration. Just component with iScroll library. You can pick build which you want.

var iScroll = require('iscroll/build/iscroll-lite')

<ReactIScroll iScroll={iScroll}>
  <div>Long content...</div>
</ReactIScroll>

You can customize iScroll options with options property. Supports all from iScroll manual

var iScroll = require('iscroll/build/iscroll-probe')
var options = {
  mouseWheel: true,
  scrollbars: true,
  freeScroll: true,
  invertWheelDirection: true,
  momentum: false,
  indicators: {...}
}

<ReactIScroll iScroll={iScroll}
              options={options}>
  <div>Long content...</div>
</ReactIScroll>

Component supports all iScroll events. All of them passed iScroll instance to callback.

var iScroll = require('iscroll/build/iscroll-probe')

<ReactIScroll iScroll={iScroll}
              onBeforeScrollStart={this.onBeforeScrollStart}
              onScrollCancel={this.onScrollCancel}
              onScrollStart={this.onScrollStart}
              onScroll={this.onScroll}
              onScrollEnd={this.onScrollEnd}
              onFlick={this.onFlick}
              onZoomStart={this.onZoomStart}
              onZoomEnd={this.onZoomEnd}>
  <div>Long content...</div>
</ReactIScroll>

Plus there is one special event 'onRefresh' which is triggered when iScroll is refreshed. You can then get state of iScroll like iscroll.hasVerticalScroll, iscroll.x or iscroll.scale.

Watch out when updating state by value from iScroll. Always update state only when value changed to prevent circular updating (stack level too deep)

var iScroll = require('iscroll/build/iscroll-lite')

onRefresh: function(iScrollInstance) {
  var yScroll = iScrollInstance.y;

  console.log("vertical position:" + yScroll)

  if(this.state.y != yScroll) {
    this.setState({y: yScroll})
  }
},
render: function() {
  return (
    <ReactIScroll iScroll={iScroll}
                  onRefresh={this.onRefresh}>
      <div>Long content...</div>
    </ReactIScroll>
  )
}

function component.getIScroll()

Return iScroll instance if initialized

function component.withIScroll([waitForInit], callback)

Run callback with iScroll instance as argument if instance is initialized. You can pass true as first argument for call callback after iScroll is initialized

  onSomethingClick: function(ev) {
    ev.preventDefault()
    this.refs.iScroll.withIScroll(function(iScroll) {
      iScroll.scrollTo(0,0)
    })
  },

  render: function() {
    return(
      <div>
        <ReactIScroll ref="iScroll"
                      iScroll={iScroll}
                      onRefresh={this.onRefresh}>
          <div>Long content...</div>
          <a class="#" onClick={this.onSomethingClick}>Back to top</a>
        </ReactIScroll>
      </div>
    )
  }

Horizontal scroll

Common usecase of horizontal scrolling

var React = require('react'),
    ReactIScroll = require('react-iscroll'),
    iScroll = require('iscroll');

var HorizontalScroll = React.createClass({
  render: function() {
    return (
      <ReactIScroll iScroll={iScroll}
                    options={{mouseWheel: true, scrollbars: true, scrollX: true}}>
        <div style={{width:'200%'}}>
          <ul>
            {listOfLi}
          </ul>
        </div>
      </ReactIScroll>
    )
  }
})

Example

There is example application. You can run it with this commands:

• npm install
• npm run example
• open http://localhost:8080/

To-Do

• Add tests
• Think about shouldComponentUpdate. Now it is always true because this.props.children are new object everytime and can't be compared via == or ===. Maybe there is some way how to cheaply compare them.
• Don't initialize IScroll when there is no child supplied.

Done

• Make this README.md :)
• Trigger onRefresh event when iScroll is internally refreshed (e.g. on window resize)
• Do not require('iscroll') by itself. Instead pass it in props (there is few different versions of iScroll and you want to pick correct one for you)
• Publish to npm
• Convert source code into Babel

License

React iScroll is released under the MIT License.