微信小程序8种数据通信的方式小结

<my-component list="{{list}}"></my-component>

Component({
 properties:{
  list:{
   type: Array,
   value: []
  }
 },
 attached(){
  console.log(this.list)
 }
})

Component({
 attached(){
  this.triggerEvent('customEvent',{ id: 10 })
 }
})

<my-component list="{{list}}" bind:customEvent="customEvent"></my-component>

Page({
 customEvent(e){
  console.log(e.detail.id)
 }
})

<my-component id="mycomponent" list="{{list}}"></my-component>

Page({
 onLoad(){
  let mycomponent = this.selectComponent('#mycomponent')
  mycomponent.setData({
   list: []
  })
 }
})

Component({
 attached(){
  let parent = this.selectOwnerComponent()
  console.log(parent)
 }
})

App({
 globalData:{
  list:[]
 }
})

const app = getApp()
Page({
 onLoad(){
  app.globalData.list.push({
   id: 10
  })
 }
})

const app = getApp()
Page({
 onLoad(){
  console.log(app.globalData.list) // [{id:10}]
 }
})

wx.setStorageSync('timestamp', Date.now())
wx.getStorageSync('timestamp')
wx.removeStorageSync('timestamp')

class EventBus{
 constructor(){
  this.task = {}
 }

 on(name, cb){
  if(!this.task[name]){
   this.task[name] = []
  }
  typeof cb === 'function' && this.task[name].push(cb)
 }

 emit(name, ...arg){
  let taskQueen = this.task[name]
  if(taskQueen && taskQueen.length > 0){
   taskQueen.forEach(cb=>{
    cb(...arg)
   })
  }
 }

 off(name, cb){
  let taskQueen = this.task[name]
  if(taskQueen && taskQueen.length > 0){
   let index = taskQueen.indexOf(cb)
   index != -1 && taskQueen.splice(index, 1)
  }
 }

 once(name, cb){
  function callback(...arg){
   this.off(name, cb)
   cb(...arg)
  }
  typeof cb === 'function' && this.on(name, callback)
 }
}

export default EventBus

import EventBus from '/util/EventBus'

wx.$bus = new EventBus()
page1.js
Page({
 onLoad(){
  wx.$bus.on('add', this.addHandler)
 },
 addHandler(a, b){
  console.log(a+b)
 }
})

Page({
 onLoad(){
  wx.$bus.emit('add', 10, 20)
 },
})

Page({
 onLoad(){
  let pages = getCurrentPages()
  let lastPage = pages[pages.length-2]
  lastPage.setData({
   list: []
  })
 }
})