Entry Component

Every Taro application needs an entry component to register the application. The default entry file is app.js in the src directory.

In the entry component we can set the global state or access the lifecycle of the mini program entry instance.

Example Code

Class Component

app.js

import React, { Component } from 'react'

// If we use the Redux
import { Provider } from 'react-redux'
import configStore from './store'

// Global Style
import './app.css'

const store = configStore()

class App extends Component {
  // All React component methods can be used
  componentDidMount () {}

  // onLaunch
  onLaunch () {}

  //  onShow
  componentDidShow () {}

  //  onHide
  componentDidHide () {}

  render () {
    // Nothing will be rendered in the entry component, but we can do something like state management here
    return (
      <Provider store={store}>
        /* this.props.children is the page that will be rendered */
        {this.props.children}
      </Provider>
    )
  }
}

export default App

Functional Component

app.js

import React, { useEffect } from 'react'

// The additional hooks added to Taro should be brought in from '@tarojs/taro'
import { useDidShow, useDidHide } from '@tarojs/taro'

// Global Style
import { Provider } from 'react-redux'
import configStore from './store'

// Global Style
import './app.css'

const store = configStore()

function App (props) {
  // All React Hooks can be used
  useEffect(() => {})

  // onShow
  useDidShow(() => {})

  //  onHide
  useDidHide(() => {})

  return (
    // Nothing will be rendered in the entry component, but we can do something like state management here
    <Provider store={store}>
      {/* props.children is the page that will be rendered */}
      {props.children}
    </Provider>
  )
}

export default App

Entry Component Configuration

Please refer to the global configuration

Life cycle methods

In addition to supporting React's lifecycle methods, the portal component additionally supports the following lifecycles according to the mini program's standards.

onLaunch (options)

onLaunch of the corresponding app in the mini program environment.

rogram initialization parameters can be accessed during this lifecycle by accessing the options parameter or by calling getCurrentInstance().router.

Parameters

options

Proerty	Type	Description
path	string	Path for launch mini-program
scene	number	Scene values for launch mini-program
query	Object	Parameters for launch mini-program
shareTicket	string	shareTicket，See Get More Forwarding Information
referrerInfo	Object	Source information. Source information. Returned when accessing an mini-program from another mini-program, public number or app. Otherwise returns {}

options.referrerInfo

Proerty	Type	Description
appId	string	Source mini-program, or public number (in WeChat)）
extraData	Object	The data passed from the source mini-program is supported by WeChat and Baidu smart-program at scene=1037 or 1038
sourceServiceId	string	Source plugin, visible when in plugin run mode

The options parameter may vary from field to field in different mini-program

Scene values , there are differences in WeChat Mini-program and Baidu Smart-program, please refer to them respectively Wechat Mini-program 和 Baidu Smart-program Documents

componentDidShow (options)

Triggered when the program is started, or foregrounded.

As with the onLaunch lifecycle, program initialization parameters can be accessed during this lifecycle by accessing the options parameter or calling getCurrentInstance().router.

The parameters are basically the same as those obtained in onLaunch, but with two additional parameters in Baidu Smart-program as follows.

Proerty	Type	Description
entryType	string	Source identifier, take the value of user/ schema /sys : user：Indicates before and after passing home Switching or unlocking the screen, etc. to bring up. schema：Indicates a protocol call-up; sys：Other
appURL	string	The call-up protocol at the time of the presentation, which exists only if the value of entryType is schema

componentDidHide ()

Triggered when the program switches to the background.

onPageNotFound (Object)

Triggered when the page to be opened by the program does not exist.

Parameters

Object

Proerty	Type	Description
path	string	Path to non-existent page
query	Object	Open the query parameter of a non-existent page
isEntryPage	boolean	Whether it is the first page of this launch