@ohos.commonEvent (Common Event) (System API)

The CommonEvent module provides common event capabilities, including the capabilities to publish, subscribe to, and unsubscribe from common events, as well obtaining and setting the common event result code and result data.

NOTE The APIs provided by this module are no longer maintained since API version 9. You are advised to use @ohos.commonEventManager.

The initial APIs of this module are supported since API version 7. Newly added APIs will be marked with a superscript to indicate their earliest API version.

This topic describes only system APIs provided by the module. For details about its public APIs, see CommonEvent.

Modules to Import

import commonEvent from '@ohos.commonEvent';

Support

A system common event is an event that is published by a system service or system application and requires specific permissions to subscribe to. To publish or subscribe to this type of event, you must follow the event-specific definitions.

For details about the definitions of all system common events, see System Common Events.

commonEvent.publishAsUser^(deprecated)

publishAsUser(event: string, userId: number, callback: AsyncCallback<void>): void

Publishes a common event to a specific user. This API uses an asynchronous callback to return the result.

NOTE This API is supported since API version 8 and deprecated since API version 9. You are advised to use commonEventManager.publishAsUser instead.

System capability: SystemCapability.Notification.CommonEvent

System API: This is a system API and cannot be called by third-party applications.

Parameters

Name	Type	Mandatory	Description
event	string	Yes	Name of the common event to publish.
userId	number	Yes	User ID.
callback	AsyncCallback<void>	Yes	Callback used to return the result.

Example

import Base from '@ohos.base';

// Callback for common event publication
function publishCB(err:Base.BusinessError) {
	if (err.code) {
        console.error(`publishAsUser failed, code is ${err.code}`);
    } else {
        console.info("publishAsUser");
    }
}

// Specify the user to whom the common event will be published.
let userId = 100;

// Publish a common event.
commonEvent.publishAsUser("event", userId, publishCB);

commonEvent.publishAsUser^(deprecated)

publishAsUser(event: string, userId: number, options: CommonEventPublishData, callback: AsyncCallback<void>): void

Publishes a common event with given attributes to a specific user. This API uses an asynchronous callback to return the result.

NOTE This API is supported since API version 8 and deprecated since API version 9. You are advised to use commonEventManager.publishAsUser instead.

System capability: SystemCapability.Notification.CommonEvent

System API: This is a system API and cannot be called by third-party applications.

Parameters

Name	Type	Mandatory	Description
event	string	Yes	Name of the common event to publish.
userId	number	Yes	User ID.
options	CommonEventPublishData	Yes	Attributes of the common event to publish.
callback	AsyncCallback<void>	Yes	Callback used to return the result.

Example

import Base from '@ohos.base';
import CommonEventManager from '@ohos.commonEventManager';

// Attributes of a common event.
let options:CommonEventManager.CommonEventPublishData = {
	code: 0,			 // Result code of the common event.
	data: "initial data",// Result data of the common event.
}

// Callback for common event publication
function publishCB(err:Base.BusinessError) {
    if (err.code) {
        console.error(`publishAsUser failed, code is ${err.code}`);
    } else {
        console.info("publishAsUser");
    }
}

// Specify the user to whom the common event will be published.
let userId = 100;

// Publish a common event.
commonEvent.publishAsUser("event", userId, options, publishCB);

unsubscribe(subscriber: CommonEventSubscriber, callback?: AsyncCallback<void>): void

Unsubscribes from common events. This API uses an asynchronous callback to return the result.

NOTE
This API is supported since API version 7 and deprecated since API version 9. You are advised to use commonEventManager.subscribe instead.

System capability: SystemCapability.Notification.CommonEvent

Parameters

Name	Type	Mandatory	Description
subscriber	CommonEventSubscriber	Yes	Subscriber object.
callback	AsyncCallback<void>	No	Callback used to return the result.

Example

import Base from '@ohos.base';
import CommonEventManager from '@ohos.commonEventManager';

let subscriber:CommonEventManager.CommonEventSubscriber;	// Used to save the created subscriber object for subsequent subscription and unsubscription.

// Subscriber information.
let subscribeInfo:CommonEventManager.CommonEventSubscribeInfo = {
    events: ["event"]
};

// Callback for common event subscription.
function subscribeCB(err:Base.BusinessError, data:CommonEventManager.CommonEventData) {
    if (err.code) {
        console.error(`subscribe failed, code is ${err.code}`);
    } else {
        console.info("subscribe " + JSON.stringify(data));
    }
}

// Callback for subscriber creation.
function createCB(err:Base.BusinessError, commonEventSubscriber:CommonEventManager.CommonEventSubscriber) {
    if (err.code) {
        console.error(`createSubscriber failed, code is ${err.code}`);
    } else {
        console.info("createSubscriber");
        subscriber = commonEventSubscriber;
        // Subscribe to a common event.
        commonEvent.subscribe(subscriber, subscribeCB);
    }
}

// Callback for common event unsubscription.
function unsubscribeCB(err:Base.BusinessError) {
    if (err.code) {
        console.error(`unsubscribe failed, code is ${err.code}`);
    } else {
        console.info("unsubscribe");
    }
}

// Create a subscriber.
commonEvent.createSubscriber(subscribeInfo, createCB);

// Unsubscribe from the common event.
commonEvent.unsubscribe(subscriber, unsubscribeCB);