Register a Mini Program in app.js

App(object: Object)

• The App() method registers a Mini Program. It accepts an Object parameter to configure the Mini Program's lifecycle and other settings.

• You must call the App() method exactly once in app.js.

Object property descriptions

Foreground/background definition:

• When a user taps the close button in the upper-right corner or presses the device's Home button to leave Alipay, the Mini Program is not immediately destroyed. Instead, it enters the background.

• When the user returns to Alipay or reopens the Mini Program, the Mini Program moves from the background to the foreground.

• The Mini Program is permanently destroyed only if it has been in the background for a certain period or if it consumes too many system resources.

onLaunch(object: Object) and onShow(object: Object)

Object property descriptions:

For example, the schema URL to start the Mini Program is as follows:

alipays://platformapi/startapp?appId=1999&query=number%3D1&page=x%2Fy%2Fz

The parameters are parsed as follows:

query = decodeURIComponent('number%3D1');
// number=1
path = decodeURIComponent('x%2Fy%2Fz');
// x/y/z

• When the Mini Program starts for the first time, you can retrieve the values of the query and path properties from the onLaunch method.

• If the Mini Program is opened from the background using a schema, you can also obtain the values of the query and path properties from the onShow method.

App({
  onLaunch(options) {
    // First launch
    console.log(options.query);
    // {number:1}
    console.log(options.path);
    // x/y/z
  },
  onShow(options) {
    // Reopened from the background by a schema
    console.log(options.query);
    // {number:1}
    console.log(options.path);
    // x/y/z
  },
});

referrerInfo sub-property descriptions:

onHide()

The onHide() method is triggered when the Mini Program moves from the foreground to the background.

Sample code:

App({
  onHide() {
    // When entering the background
    console.log('app hide');
  },
});

onError(error: String)

This method is triggered when a script error or an API call error occurs.

App({
  onError(error) {
    // When a Mini Program execution error occurs
    console.log(error);
  },
});

onShareAppMessage(object: Object)

This method provides global sharing configuration. When page.onShareAppMessage is not set for a page, calling the share function executes the global sharing settings. For more information, see Share.

Global data

You can set global data in App() using the globalData property.

Code example:

// app.js
App({
  globalData: 1
});