# @ohos.bundle.defaultAppManager (Default Application Management)

The **DefaultAppManager** module provides APIs to query whether the current application is the default application of a specific type.

> **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

```ts
import { defaultAppManager } from '@kit.AbilityKit';
```

## defaultAppManager.ApplicationType

Enumerates the default application types.

**System capability**: SystemCapability.BundleManager.BundleFramework.DefaultApp

| Name  | Value | Description                                  |
| -------- | -------------------------------------- | -------------------------------------- |
| BROWSER  | 'Web Browser' | Default browser.                           |
| IMAGE    | 'Image Gallery' | Default image viewer.                        |
| AUDIO    | 'Audio Player' | Default audio player.                        |
| VIDEO    | 'Video Player' | Default video player.                        |
| PDF      | 'PDF Viewer' | Default PDF reader.                     |
| WORD     | 'Word Viewer' | Default Word viewer.                    |
| EXCEL    | 'Excel Viewer' | Default Excel viewer.                   |
| PPT      | 'PPT Viewer' | Default PowerPoint viewer.                     |
| EMAIL<sup>12+</sup>    | 'Email' | Default email.                     |

## defaultAppManager.isDefaultApplication

isDefaultApplication(type: string): Promise\<boolean>

Checks whether this application is the default application of a system-defined application type or a [uniform data type](../apis-arkdata/js-apis-data-uniformTypeDescriptor.md). This API uses a promise to return the result.

**System capability**: SystemCapability.BundleManager.BundleFramework.DefaultApp

**Parameters**

| Name        | Type    | Mandatory  | Description                                     |
| ----------- | ------ | ---- | --------------------------------------- |
| type  | string | Yes   | Type of the target application. It must be set to a value defined by [ApplicationType](#defaultappmanagerapplicationtype) or [UniformDataType](../apis-arkdata/js-apis-data-uniformTypeDescriptor.md).                          |

**Return value**

| Type                       | Description                |
| ------------------------- | ------------------ |
| Promise\<boolean> | Promise used to return the result. If the application is the default application, **true** is returned; otherwise, **false** is returned. |

**Error codes**

For details about the error codes, see [Universal Error Codes](../errorcode-universal.md).

| ID | Error Message                                                   |
| -------- | ---------------------------------------------------------- |
| 401 | Parameter error. Possible causes: 1. Mandatory parameters are left unspecified; 2. Incorrect parameter types. |
| 801 | Capability not supported. |

**Example**

```ts
import { defaultAppManager } from '@kit.AbilityKit';
import { BusinessError } from '@kit.BasicServicesKit';

defaultAppManager.isDefaultApplication(defaultAppManager.ApplicationType.BROWSER)
  .then((data) => {
    console.info('Operation successful. IsDefaultApplication ? ' + JSON.stringify(data));
  }).catch((error: BusinessError) => {
    console.error('Operation failed. Cause: ' + JSON.stringify(error));
  });
```

## defaultAppManager.isDefaultApplication

isDefaultApplication(type: string, callback: AsyncCallback\<boolean>): void

Checks whether this application is the default application of a system-defined application type or a [uniform data type](../apis-arkdata/js-apis-data-uniformTypeDescriptor.md). This API uses an asynchronous callback to return the result.

**System capability**: SystemCapability.BundleManager.BundleFramework.DefaultApp

**Parameters**

| Name        | Type                             | Mandatory  | Description                                     |
| ----------- | ------------------------------- | ---- | --------------------------------------- |
| type  | string                          | Yes   | Type of the target application. It must be set to a value defined by [ApplicationType](#defaultappmanagerapplicationtype) or [UniformDataType](../apis-arkdata/js-apis-data-uniformTypeDescriptor.md).                           |
| callback    | AsyncCallback\<boolean> | Yes   | Callback used to return the result. If the application is the default application, **true** is returned; otherwise, **false** is returned. |

**Error codes**

For details about the error codes, see [Universal Error Codes](../errorcode-universal.md).

| ID | Error Message                                                   |
| -------- | ---------------------------------------------------------- |
| 401 | Parameter error. Possible causes: 1. Mandatory parameters are left unspecified; 2. Incorrect parameter types. |
| 801 | Capability not supported. |

**Example**

```ts
import { defaultAppManager } from '@kit.AbilityKit';
import { BusinessError } from '@kit.BasicServicesKit';

defaultAppManager.isDefaultApplication(defaultAppManager.ApplicationType.BROWSER, (err: BusinessError, data) => {
  if (err) {
    console.error('Operation failed. Cause: ' + JSON.stringify(err));
    return;
  }
  console.info('Operation successful. IsDefaultApplication ? ' + JSON.stringify(data));
});
```

## defaultAppManager.isDefaultApplicationSync<sup>10+</sup>

isDefaultApplicationSync(type: string): boolean

Checks whether this application is the default application of a system-defined application type or a [uniform data type](../apis-arkdata/js-apis-data-uniformTypeDescriptor.md). This API returns the result synchronously.

**System capability**: SystemCapability.BundleManager.BundleFramework.DefaultApp

**Parameters**

| Name | Type  | Mandatory | Description                                    |
| -------| ------ | ---- | --------------------------------------- |
|  type  | string | Yes  | Type of the target application. It must be set to a value defined by [ApplicationType](#defaultappmanagerapplicationtype) or [UniformDataType](../apis-arkdata/js-apis-data-uniformTypeDescriptor.md).  |

**Return value**

| Type   | Description                |
| ------- | -------------------- |
| boolean | Returns **true** if the application is the default application; returns **false** otherwise. |

**Error codes**

For details about the error codes, see [Universal Error Codes](../errorcode-universal.md).

| ID | Error Message                                                   |
| -------- | ---------------------------------------------------------- |
| 401 | Parameter error. Possible causes: 1. Mandatory parameters are left unspecified; 2. Incorrect parameter types. |
| 801 | Capability not supported. |

**Example**

```ts
import { defaultAppManager } from '@kit.AbilityKit';

try {
  let data = defaultAppManager.isDefaultApplicationSync(defaultAppManager.ApplicationType.BROWSER)
  console.info('Operation successful. IsDefaultApplicationSync ? ' + JSON.stringify(data));
} catch(error) {
  console.error('Operation failed. Cause: ' + JSON.stringify(error));
};
```