When a Mini Program has more than one page, how should the pages communicate with each other?

This article gives some solution ideas for some common scenarios.

• Page jumping
• Communication through the global app object

Page Jumping​

When jumping from pageA.js page to pageB.js page, use the hmApp.gotoPage() API to pass parameters to the pageB.js page via the param parameter

pageA.js

hmApp.gotoPage({
 url: 'path/to/pageB',
 param: JSON.stringify({
   id: '0',
   type: 'normal'
 })
})

pageB.js

Page({
 onInit(params) {
   const paramsObj = JSON.parse(params)
   const { id, type } = paramsObj
   console.log(id === '0') // true
   console.log(type === 'normal') // true
 }
})

This solution can only be used for one-way passing of page jumps, if you do some operations in pageB.js and then return to the pageA.js page, calling the hmApp.goBack API does not support parameter passing, in this case you need to use the global app object to communicate

Communicating through the global app object​

In the app.js constructor parameter, pass in the globalData object

app.js

App({
 globalData: {
   type: 'normal'
 }
})

pageA.js

Page({
 build() {
   console.log(getApp()._options.globalData.type)
 }
})

pageB.js

// ...
getApp()._options.globalData.type = 'classic'

hmApp.goBack()

Our page jump is still from PageA.js to PageB.js

The globalData object mounted on the global app object is modified in pageB.js, and when we call hmApp.goBack() to return from the pageB.js page to the pageA.js page, we can get the modified type value

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