@ohos.base (Public Callback Information)

The Base module defines the public callback types of ArkTS APIs, including the common and error callbacks.

NOTE

The initial APIs of this module are supported since API version 6. Newly added APIs will be marked with a superscript to indicate their earliest API version.

Modules to Import

import base from '@ohos.base';

Callback

Callback<T> {

(data: T): void;

}

Defines a common callback.

You can set data to customize the data type of the information returned by the callback.

System capability: SystemCapability.Base

Name	Type	Mandatory	Description
data	T	Yes	Common callback information.

ErrorCallback

ErrorCallback<T extends Error = BusinessError> {

(err: T): void;

}

Defines a common callback that carries an error parameter.

The information returned by the callback is of the BusinessError type.

System capability: SystemCapability.Base

Parameters

Name	Type	Mandatory	Description
err	T	Yes	Common error information about the API invoking failure.

AsyncCallback

AsyncCallback<T, E = void> {

(err: BusinessError, data: T): void;

}

Defines a common callback that carries an error parameter and asynchronous return value.

The error parameter is of the BusinessError type.

The type of the asynchronous return value is defined by the developer.

System capability: SystemCapability.Base

Name	Type	Mandatory	Description
err	BusinessError	Yes	Common error information about the API invoking failure.
data	T	Yes	Common callback information.

BusinessError

BusinessError<T = void> extends Error {

code: number;

data?: T; }

Defines the error parameter.

System capability: SystemCapability.Base

Name	Type	Mandatory	Description
code	number	Yes	Common error information about the API invoking failure.
data	T	No	Common callback information. If this parameter is left empty, no related information is returned.