preface

Because recently began to prepare for the graduation project, my graduation project is to do a small program, then began to learn how to develop small program journey.

Taro is an open cross-end cross-framework solution that supports the use of React/Vue/Nerv frameworks to develop wechat, JD.com, Baidu, Alipay, Bytedance, QQ mini program/H5 and other applications.

Therefore, using Taro, you only need to write one set of code to have the ability to adapt to multiple applications. Taro currently has 27.9k stars on Github, which is one of the reasons why I choose to learn Taro. (although the whole tutorial pit is actually a little bit more……)

Let’s get started.

Official documents: Taro official documents

An introduction to

Because I have some front-end development experience, SO I directly from the gradual introduction to the tutorial, through the hands-on step by step.

Progressive introduction tutorial

Progressive tutorial source code

The step-by-step introduction to developing a simple V2EX forum client using Taro is divided into four parts:

Environment to prepare
Basic tutorial
Project progression and optimization
The development of diverse

Here’s a look at some of the points not covered in the tutorial and some of the key ones.

Environment to prepare

Using Taro development requires installation:

Taro CLI
Node.js

Taro CLI Installation instructions:

npm i -g @tarojs/cli
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After the installation is complete, enter taro on the terminal. If similar information is displayed, the installation is successful:

👽 Taro v3.0.0-beta.6 Usage: Taro <command> [options] options: -V, --version output the version number -h, --help output usage information Commands: init [projectName] Init a project with default templete config <cmd> Taro config create Create page for project build Build a project with options update Update packages of taro convert Convert weapp to taro info Diagnostics Taro env info  doctor Diagnose taro project help [cmd] display help for [cmd]Copy the code

Basic tutorial

component

In applets, components are divided into page components and base components. Page components are those components that can be routed to a specified page and have a life cycle. Base components are common components that do not constitute a page but are part of a page or component.

Page components

Page components are typically defined in the Pages folder:

Taking the thread_detail component as an example, there are three files in this folder:

index.css: style file
thread_detail.tsxComponents:
thread_detail.config.ts: page component configuration file

Configuration files mainly configure some basic styles and text, page configuration, such as:

backgroundTextStyle: 'light',
navigationBarBackgroundColor: '#fff',
navigationBarTitleText: 'WeChat',
navigationBarTextStyle: 'black'
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In thread_detail.config.ts it looks like this:

Export default {navigationBarTitleText: 'topic'}Copy the code

This configuration file must be written, otherwise the following error will be reported when the project is packaged:

Module not found: Can't resolve './pages/ XXX /xxx.config 'in' XXXX 'Copy the code

So let’s be careful here.

Types of components:

import React, { Component } from 'react'
import { View } from '@tarojs/components'

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

  // onLoad
  onLoad () {}

  // onReady
  onReady () {}

  / / the corresponding onShow
  componentDidShow () {}

  / / the corresponding onHide
  componentDidHide () {}

  / / corresponding onPullDownRefresh, besides componentDidShow/componentDidHide,
  // All page life cycle function names correspond to applets
  onPullDownRefresh () {}

  render () {
    return (
      <View className='index' />)}}export default Index
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Function components:

import React, { useEffect } from 'react'
import { View } from '@tarojs/components'
import {
  useReady,
  useDidShow,
  useDidHide,
  usePullDownRefresh
} from '@tarojs/taro'

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

  / / the corresponding onReady
  useReady(() = > {})

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

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

  // Taro implements custom React Hooks for all applet page lifecyres
  // For details, please refer to: [Taro Documentation] -> [Advanced Guidelines] -> Hooks]
  usePullDownRefresh(() = > {})

  return (
    <View className='index' />)}export default Index
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Based on the component

The base components are typically defined under the Components folder:

There is no need to set up configuration files for each component.

Entrance to the configuration

App.config. ts is the entry configuration file where you can configure the page path list, the global default window representation, and so on. Taro’s configuration specification is based on the global configuration of wechat applets: wechat applets global configuration.

In V2EX, the global configuration is as follows:

// app.config.ts
export default {
  pages: [
    'pages/index/index'.'pages/nodes/nodes'.'pages/hot/hot'.'pages/node_detail/node_detail'.'pages/thread_detail/thread_detail',].tabBar: {
    list: [{
      'iconPath': 'resource/latest.png'.'selectedIconPath': 'resource/lastest_on.png'.pagePath: 'pages/index/index'.text: 'new'
    }, {
      'iconPath': 'resource/hotest.png'.'selectedIconPath': 'resource/hotest_on.png'.pagePath: 'pages/hot/hot'.text: 'hot'
    }, {
      'iconPath': 'resource/node.png'.'selectedIconPath': 'resource/node_on.png'.pagePath: 'pages/nodes/nodes'.text: 'nodes'}].'color': '# 000'.'selectedColor': '#56abe4'.'backgroundColor': '#fff'.'borderStyle': 'white'
  },
  window: {
    backgroundTextStyle: 'light'.navigationBarBackgroundColor: '#fff'.navigationBarTitleText: 'WeChat'.navigationBarTextStyle: 'black'}}Copy the code

routing

Routing hop

In Taro, you can use Taro’s navigateTo method to redirect routes:

Taro.navigateTo({ url: '/pages/thread_detail/thread_detail' })
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This usage is similar to the function.history.push (‘/ XXX ‘) in React.

Routing parameters

In the page component, either getCurrentInstance().router or Current. Router? .params gets the routing parameters of the current page:

import Taro, { Current } from '@tarojs/taro';

// Inside the component
const{ full_name } = Current.router? .params;Copy the code

The life cycle

Both the React component lifecycle methods and the applet lifecycle methods are supported in Taro, but it is important to note when and in what order they are triggered. See the official documentation: Lifecycle triggering mechanisms.

Built-in component

Taro was developed using built-in components of the applet specification, such as
,
, , etc., which are cross-platform components.

To use these built-in components in React, we must import them from @tarojs/ Components. The props of the component follow the big camel name convention:

// Small program writing
<view hover-class='test' />
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/ / Taro
import { View } from '@tarojs/components'

<View hoverClass='test' />
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The event

Events in Taro follow the camelCase naming convention, and all built-in event names start with ON.

In the event callback function, the first argument is the event itself, where stopPropagation is called to prevent bubbling.

function Comp () {
  function clickHandler (e) {
    e.stopPropagation() // Prevent bubbling
  }

  function scrollHandler () {}
  
  // Only the applet bindtap corresponds to Taro's onClick
  // Replace bind with ON to represent the name of the Taro event (with the exception of alipay applet, whose events start with ON)
  return <ScrollView onClick={clickHandler} onScroll={scrollHandler} />
}
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Project progression and optimization

After the project is developed, we want to see how the effect of the project is, how to do it? At that time, I was a little confused, so I turned to an official Taro Taro video for a 5-minute hands-on mini program and found the answer.

First, package and compile. Using the Taro CLI-generated project, package.json has been configured with instructions to package and compile various applets:

For example, IF I want to package the small wechat program, I will enter:

npm run dev:weapp
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NPM run dev is executed for debugging, and NPM run Build is executed for package build to production.

If you want multiple compilations, modify the outputRoot property in index.js under config:

outputRoot: `dist/${process.env.TARO_ENV}`
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In this way, files packaged on all ends can be stored in the dist folder at the same time. For example, the path of wechat mini-programs is dist/ appellate P, and that of H5 is dist/ H5.

Then, open the wechat developer tool, import the packaged and compiled project, there is the effect:

However, at this time, my project encountered a bug, and an error was reported in the wechat developer tool:

I didn’t read the error information carefully at that time. Actually, there was a prompt error position when I clicked in the second line Thread. Render. I thought: This can’t be debugged… There’s no console.log. (Actually, you can.)

So I thought, could it be packaged as H5 and debugged in the browser, so that it would be the same as front-end development? So he turned the other way. But in the browser, there will be a problem of cross-domain, localhost’s ask https://www.v2ex.com/api/ for a breach of the browser’s same origin policy. Applets are not limited by the same origin policy, so this problem does not occur.

`Taro`H5 Cross domain problem solving

First, add the h5 configuration in config/dev.js:

h5: {
    devServer: {
        proxy: {
            '/api/': {
                target: "https://www.v2ex.com".changeOrigin: true
                // pathRewrite: {
                // '^/api/': '/'
                // },}}}}Copy the code

The configuration is the devServer configuration for WebPack, see the blog: Proxy cross Domain for devServer

2. Modify HOST in api.ts:

const HOST_URI = 'https://www.v2ex.com/api/'

/ / changed to
const HOST_URI = '/api/'
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Why did you change that? Because in proxy, we will check whether the request starts with/API /. If it starts with HTTP, we will check for a mismatch, do not go through proxy, and cross domain failure. The default domain name http://localhost:xxxx will be changed to target, which is the https://www.v2ex.com address. But under the browser F12, Network – > Headers or see http://localhost:xxxx/api/xxx, but the real request address is: https://www.v2ex.com/api/xxx.

The pathRewrite attribute needs to be added when you meet/API/and do the proxy, but there is no/API/in the real request, so you remove/API/from pathRewrite, so that both the identifier and the request interface can remove/API /.

Run NPM run dev:h5, you can view the result in the browser:

Finally, the problem was caused by writing the life cycle function componentWillMount as componentWillUnmount. I searched for a long time, so that I wanted to hammer myself to death.

React doesn’t recommend using componentWillMount anymore, so we should put data fetching in componentDidMount:

async componentDidMount() {
    this.setState({
      thread: this.props.thread
    })
}
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Add a layer of judgment to render:

/ / components
// Render after loading thread data to prevent property of undefined error
const attrLen = Object.keys(thread).length;

{attrLen ? <Thread
    node={thread.node}
    title={thread.title}
    last_modified={thread.last_modified}
    replies={thread.replies}
    tid={thread.id}
    member={thread.member}
    not_navi={true}
/> : null}
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In fact, wechat Developer tool also has a complete debugger, you can see console.log and other results, so we can directly modify the code in VSCode, after CTRL s, you can see the corresponding rendering results in wechat Developer tool, you can also debug by looking at the Console. However, wechat developer tools do not seem to be able to use Redux debugging tools, this will be studied later.

Refactoring this demo using hooks: taro-mini-Program.

Learning materials

Learn excellent resources: awesome- Taro

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Taro introductory and Trampling tour

preface

An introduction to

Environment to prepare

Basic tutorial

component

Page components

Based on the component

Entrance to the configuration

routing

Routing hop

Routing parameters

The life cycle

Built-in component

The event

Project progression and optimization

`Taro`H5 Cross domain problem solving

Learning materials

Taro introductory and Trampling tour

preface

An introduction to

Environment to prepare

Basic tutorial

component

Page components

Based on the component

Entrance to the configuration

routing

Routing hop

Routing parameters

The life cycle

Built-in component

The event

Project progression and optimization

TaroH5 Cross domain problem solving

Learning materials

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`Taro`H5 Cross domain problem solving