Event4+

Interface Declaration

{ "name": "system.event" }

Import Module

import event from '@system.event' 
// or 
const event = require('@system.event')

Interface Definition

event.publish (OBJECT)

Publish a public event.

Parameters:

Parameter Name	Type	Required	Description
eventName	String	Yes	Event name. Reserved names for public events are occupied by the system. Do not use them.
options	Object	No	Event parameters

options Parameters:

Parameter Name	Type	Required	Description
params	Object	No	Event parameters
permissions	Array	No	Permissions of subscribers. Only packages with permissions can receive the sent event.

Public Events Supported by the System:

System Internal Event Name	Permissions Required for Subscribers	Description
usual.event.BATTERY_CHANGED	None	Battery level changed. Parameter: level: between 0.0 and 1.0
usual.event.DISCHARGING	None	Charging stopped
usual.event.CHARGING	None	Charging started

Return Value:

None

Example:

event.publish({
  eventName: 'myEventName',
  options: {
    params: { age: 10, name: 'peter' },
    permissions: ['com.example.demo']
  }
})

event.subscribe(OBJECT)

Subscribe to a public event.

Parameters:

Parameter Name	Type	Required	Description
eventName	String	Yes	Event name
callback	Function	Yes	Callback function

Callback Parameters:

Parameter Name	Type	Required	Description
params	Object	No	Event parameters
package	String	No	Package name of the event sender

Return Value:

Type	Required	Description
Number	Yes	Event ID. Returns undefined if subscription fails.

Example:

const evtId = event.subscribe({
  eventName: 'myEventName',
  callback: function(res) {
    if (res.package === 'com.example.demo') {
      console.log(res.params)
    }
  }
})
console.log(evtId)

event.unsubscribe(OBJECT)

Unsubscribe from a public event.

Parameters:

Parameter Name	Type	Required	Description
id	Number	Yes	Subscription ID

Example:

const evtId = event.subscribe({
  eventName: 'myEventName',
  callback: function(res) {
    if (res.package === 'com.example.demo') {
      console.log(res.params)
    }
  }
})

event.unsubscribe({ id: evtId })

Support Details

Device Product	Description
Xiaomi S1 Pro Sports Health Watch	Not supported
Xiaomi Band 8 Pro	Not supported
Xiaomi Watch S3	Not supported
Redmi Watch 4	Not supported
Xiaomi Wrist ECG and Blood Pressure Monitor	Not supported
Xiaomi Watch S4	Supported
REDMI Watch 5	Supported