@ohos.commonEventManager (Common Event)

The CommonEventManager module provides common event capabilities, including the capabilities to publish, subscribe to, and unsubscribe from common events.

NOTE

The initial APIs of this module are supported since API version 9. Newly added APIs will be marked with a superscript to indicate their earliest API version.

Modules to Import

import CommonEventManager from '@ohos.commonEventManager';

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.

CommonEventManager.publish

publish(event: string, callback: AsyncCallback<void>): void

Publishes a common event and executes an asynchronous callback after the event is published.

System capability: SystemCapability.Notification.CommonEvent

Parameters

Error codes

For details about the error codes, see Event Error Codes.

Example

import Base from '@ohos.base';

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

// Publish a common event.
try {
    CommonEventManager.publish("event", publishCB);
} catch (error) {
    let err:Base.BusinessError = error as Base.BusinessError;
    console.error(`publish failed, code is ${err.code}, message is ${err.message}`);
}

CommonEventManager.publish

publish(event: string, options: CommonEventPublishData, callback: AsyncCallback<void>): void

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

System capability: SystemCapability.Notification.CommonEvent

Parameters

Error codes

For details about the error codes, see Event Error Codes.

Example

import Base from '@ohos.base';

// 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.
	isOrdered: true	 // The common event is an ordered one.
}

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

// Publish a common event.
try {
    CommonEventManager.publish("event", options, publishCB);
} catch (error) {
    let err:Base.BusinessError = error as Base.BusinessError;
    console.error(`publish failed, code is ${err.code}, message is ${err.message}`);
}

CommonEventManager.publishAsUser

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.

System capability: SystemCapability.Notification.CommonEvent

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

Parameters

Error codes

For details about the error codes, see Event Error Codes.

Example

import Base from '@ohos.base';

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

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

// Publish a common event.
try {
    CommonEventManager.publishAsUser("event", userId, publishCB);
} catch (error) {
    let err:Base.BusinessError = error as Base.BusinessError;
    console.error(`publishAsUser failed, code is ${err.code}, message is ${err.message}`);
}

CommonEventManager.publishAsUser

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.

System capability: SystemCapability.Notification.CommonEvent

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

Parameters

Error codes

For details about the error codes, see Event Error Codes.

Example

import Base from '@ohos.base';

// 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) {
        console.error(`publishAsUser failed, code is ${err.code}, message is ${err.message}`);
    } else {
        console.info("publishAsUser");
    }
}

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

// Publish a common event.
try {
    CommonEventManager.publishAsUser("event", userId, options, publishCB);
} catch (error) {
    let err:Base.BusinessError = error as Base.BusinessError;
    console.error(`publishAsUser failed, code is ${err.code}, message is ${err.message}`);
}

CommonEventManager.createSubscriber

createSubscriber(subscribeInfo: CommonEventSubscribeInfo, callback: AsyncCallback<CommonEventSubscriber>): void

Creates a subscriber. This API uses an asynchronous callback to return the result.

System capability: SystemCapability.Notification.CommonEvent

Parameters

Example

import Base from '@ohos.base';

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 subscriber creation.
function createCB(err:Base.BusinessError, commonEventSubscriber:CommonEventManager.CommonEventSubscriber) {
    if(!err) {
        console.info("createSubscriber");
        subscriber = commonEventSubscriber;
    } else {
        console.error(`createSubscriber failed, code is ${err.code}, message is ${err.message}`);
    }
}

// Create a subscriber.
try {
    CommonEventManager.createSubscriber(subscribeInfo, createCB);
} catch (error) {
    let err:Base.BusinessError = error as Base.BusinessError;
    console.error(`createSubscriber failed, code is ${err.code}, message is ${err.message}`);
}

CommonEventManager.createSubscriber

createSubscriber(subscribeInfo: CommonEventSubscribeInfo): Promise<CommonEventSubscriber>

Creates a subscriber. This API uses a promise to return the result.

System capability: SystemCapability.Notification.CommonEvent

Parameters

Return value

Example

import Base from '@ohos.base';

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

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

// Create a subscriber.
CommonEventManager.createSubscriber(subscribeInfo).then((commonEventSubscriber:CommonEventManager.CommonEventSubscriber) => {
    console.info("createSubscriber");
    subscriber = commonEventSubscriber;
}).catch((err:Base.BusinessError) => {
    console.error(`createSubscriber failed, code is ${err.code}, message is ${err.message}`);
});

CommonEventManager.createSubscriberSync¹⁰⁺

createSubscriberSync(subscribeInfo: CommonEventSubscribeInfo): CommonEventSubscriber

Creates a subscriber. The API returns the result synchronously.

System capability: SystemCapability.Notification.CommonEvent

Parameters

Return value

Example

import Base from '@ohos.base';

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

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

// Create a subscriber.
try {
    subscriber = CommonEventManager.createSubscriberSync(subscribeInfo);
} catch (error) {
    let err:Base.BusinessError = error as Base.BusinessError;
    console.error(`createSubscriberSync failed, code is ${err.code}, message is ${err.message}`);
}

CommonEventManager.subscribe

subscribe(subscriber: CommonEventSubscriber, callback: AsyncCallback<CommonEventData>): void

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

System capability: SystemCapability.Notification.CommonEvent

Parameters

Error codes

For details about the error codes, see Event Error Codes.

Example

import Base from '@ohos.base';

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) {
        console.error(`subscribe failed, code is ${err.code}, message is ${err.message}`);
    } else {
        console.info("subscribe ");
    }
}

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

// Create a subscriber.
try {
    CommonEventManager.createSubscriber(subscribeInfo, createCB);
} catch (error) {
    let err:Base.BusinessError = error as Base.BusinessError;
    console.error(`createSubscriber failed, code is ${err.code}, message is ${err.message}`);
}

CommonEventManager.unsubscribe

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

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

System capability: SystemCapability.Notification.CommonEvent

Parameters

Error codes

For details about the error codes, see Event Error Codes.

Example

import Base from '@ohos.base';

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) {
        console.error(`subscribe failed, code is ${err.code}, message is ${err.message}`);
    } else {
        console.info("subscribe");
    }
}
// Callback for subscriber creation.
function createCB(err:Base.BusinessError, commonEventSubscriber:CommonEventManager.CommonEventSubscriber) {
    if (err) {
        console.error(`createSubscriber failed, code is ${err.code}, message is ${err.message}`);
    } else {
        console.info("createSubscriber");
        subscriber = commonEventSubscriber;
        // Subscribe to a common event.
        try {
            CommonEventManager.subscribe(subscriber, subscribeCB);
        } catch (error) {
            let err:Base.BusinessError = error as Base.BusinessError;
            console.error(`subscribe failed, code is ${err.code}, message is ${err.message}`);
        }
    }
}
// Callback for common event unsubscription.
function unsubscribeCB(err:Base.BusinessError) {
    if (err) {
        console.error(`unsubscribe failed, code is ${err.code}, message is ${err.message}`);
    } else {
        console.info("unsubscribe");
    }
}
// Create a subscriber.
try {
    CommonEventManager.createSubscriber(subscribeInfo, createCB);
} catch (error) {
    let err:Base.BusinessError = error as Base.BusinessError;
    console.error(`createSubscriber failed, code is ${err.code}, message is ${err.message}`);
}

// Unsubscribe from the common event.
// Wait until execution of the asynchronous API subscribe is completed. Add setTimeout when necessary.
setTimeout(() => {
  try {
    CommonEventManager.unsubscribe(subscriber, unsubscribeCB);
  } catch (error) {
    let err:Base.BusinessError = error as Base.BusinessError;
    console.error(`unsubscribe failed, code is ${err.code}, message is ${err.message}`);
  }
}, 500);

CommonEventManager.removeStickyCommonEvent¹⁰⁺

removeStickyCommonEvent(event: string, callback: AsyncCallback<void>): void

Removes a sticky common event. This API uses an asynchronous callback to return the result.

System capability: SystemCapability.Notification.CommonEvent

Required permissions: ohos.permission.COMMONEVENT_STICKY

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

Parameters

Error codes

For details about the error codes, see Event Error Codes.

Example

import Base from '@ohos.base';

CommonEventManager.removeStickyCommonEvent("sticky_event", (err:Base.BusinessError) => {
    if (err) {
        console.info(`Remove sticky event AsyncCallback failed, errCode: ${err.code}, errMes: ${err.message}`);
        return;
    }
    console.info(`Remove sticky event AsyncCallback success`);
});

CommonEventManager.removeStickyCommonEvent¹⁰⁺

removeStickyCommonEvent(event: string): Promise<void>

Removes a sticky common event. This API uses a promise to return the result.

System capability: SystemCapability.Notification.CommonEvent

Required permissions: ohos.permission.COMMONEVENT_STICKY

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

Parameters

Return value

Error codes

For details about the error codes, see Event Error Codes.

Example

import Base from '@ohos.base';

CommonEventManager.removeStickyCommonEvent("sticky_event").then(() => {
    console.info(`Remove sticky event AsyncCallback success`);
}).catch ((err:Base.BusinessError) => {
    console.info(`Remove sticky event AsyncCallback failed, errCode: ${err.code}, errMes: ${err.message}`);
});

CommonEventManager.setStaticSubscriberState¹⁰⁺

setStaticSubscriberState(enable: boolean, callback: AsyncCallback<void>): void;

Enables or disables static subscription for the current application. This API uses an asynchronous callback to return the result.

Model restriction: This API can be used only in the stage model.

System capability: SystemCapability.Notification.CommonEvent

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

Parameters

Error codes

For details about the error codes, see Event Error Codes.

Example

import Base from '@ohos.base';

CommonEventManager.setStaticSubscriberState(true, (err:Base.BusinessError) => {
    if (!err) {
        console.info(`Set static subscriber state callback failed, err is null.`);
        return;
    }
    if (err.code !== undefined && err.code != null) {
        console.info(`Set static subscriber state callback failed, errCode: ${err.code}, errMes: ${err.message}`);
        return;
    }
    console.info(`Set static subscriber state callback success`);
});

CommonEventManager.setStaticSubscriberState¹⁰⁺

setStaticSubscriberState(enable: boolean): Promise<void>;

Enables or disables static subscription for the current application. This API uses a promise to return the result.

Model restriction: This API can be used only in the stage model.

System capability: SystemCapability.Notification.CommonEvent

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

Parameters

Return value

Error codes

For details about the error codes, see Event Error Codes.

Example

import Base from '@ohos.base';

CommonEventManager.setStaticSubscriberState(false).then(() => {
    console.info(`Set static subscriber state promise success`);
}).catch ((err:Base.BusinessError) => {
    console.info(`Set static subscriber state promise failed, errCode: ${err.code}, errMes: ${err.message}`);
});