Class (MediaAssetManager)

The MediaAssetManager class is used for manipulating the read and write operations of media assets.

NOTE

• The initial APIs of this module are supported since API version 10. Newly added APIs will be marked with a superscript to indicate their earliest API version.
• The initial APIs of this class are supported since API version 11.

Modules to Import

import { photoAccessHelper } from '@kit.MediaLibraryKit';

requestImage¹¹⁺

static requestImage(context: Context, asset: PhotoAsset, requestOptions: RequestOptions, dataHandler: MediaAssetDataHandler<image.ImageSource>): Promise<string>

Requests an image. This API uses a promise to return the result.

System capability: SystemCapability.FileManagement.PhotoAccessHelper.Core

Required permissions: ohos.permission.READ_IMAGEVIDEO

• When this API is called in picker mode to request image resources, the ohos.permission.READ_IMAGEVIDEO permission is not required. For details, see Obtaining an Image or Video by URI.
• For images saved to the media library by this application, the application can access them without the ohos.permission.READ_IMAGEVIDEO permission.

Parameters

Name	Type	Mandatory	Description
context	Context	Yes	Context of the ability instance.
asset	PhotoAsset	Yes	Image to request.
requestOptions	RequestOptions	Yes	Options for requesting the image.
dataHandler	MediaAssetDataHandler<image.ImageSource>	Yes	Media asset handler, which invokes a callback to return the image when the requested image is ready.

Return value

Type	Description
Promise<string>	Promise used to return the request ID, which can be used in cancelRequest to cancel a request.

Error codes

For details about the error codes, see Universal Error Codes and File Management Error Codes.

ID	Error Message
201	Permission denied
401	Parameter error. Possible causes: 1. Mandatory parameters are left unspecified; 2. Incorrect parameter types; 3. Parameter verification failed.
14000011	System inner fail.

Example

For details about how to create a phAccessHelper instance, see the example provided in photoAccessHelper.getPhotoAccessHelper.

import { dataSharePredicates } from '@kit.ArkData';
import { image } from '@kit.ImageKit';

class MediaHandler implements photoAccessHelper.MediaAssetDataHandler<image.ImageSource> {
  onDataPrepared(data: image.ImageSource) {
    if (data === undefined) {
      console.error('Error occurred when preparing data');
      return;
    }
    console.info('on image data prepared');
  }
}

async function example(phAccessHelper: photoAccessHelper.PhotoAccessHelper, context: Context) {
  console.info('requestImage');
  let predicates: dataSharePredicates.DataSharePredicates = new dataSharePredicates.DataSharePredicates();
  let fetchOptions: photoAccessHelper.FetchOptions = {
    fetchColumns: [],
    predicates: predicates
  };
  let requestOptions: photoAccessHelper.RequestOptions = {
    deliveryMode: photoAccessHelper.DeliveryMode.HIGH_QUALITY_MODE,
  }
  const handler = new MediaHandler();

  phAccessHelper.getAssets(fetchOptions, async (err, fetchResult) => {
    console.info('fetchResult success');
    let photoAsset: photoAccessHelper.PhotoAsset = await fetchResult.getFirstObject();
    if (photoAsset === undefined) {
      console.error('photoAsset is undefined');
      return;
    }
    await photoAccessHelper.MediaAssetManager.requestImage(context, photoAsset, requestOptions, handler);
    console.info('requestImage successfully');
  });
}

requestImageData¹¹⁺

static requestImageData(context: Context, asset: PhotoAsset, requestOptions: RequestOptions, dataHandler: MediaAssetDataHandler<ArrayBuffer>): Promise<string>

Requests image data. This API uses a promise to return the result.

System capability: SystemCapability.FileManagement.PhotoAccessHelper.Core

Required permissions: ohos.permission.READ_IMAGEVIDEO

• When this API is called in picker mode to request image resources, the ohos.permission.READ_IMAGEVIDEO permission is not required. For details, see Obtaining an Image or Video by URI.
• For images saved to the media library by this application, the application can access them without the ohos.permission.READ_IMAGEVIDEO permission.

Parameters

Name	Type	Mandatory	Description
context	Context	Yes	Context of the ability instance.
asset	PhotoAsset	Yes	Image to request.
requestOptions	RequestOptions	Yes	Options for requesting the image.
dataHandler	MediaAssetDataHandler<ArrayBuffer>	Yes	Media asset handler, which invokes a callback to return the image when the requested image is ready.

Return value

Type	Description
Promise<string>	Promise used to return the request ID, which can be used in cancelRequest to cancel a request.

Error codes

For details about the error codes, see Universal Error Codes and File Management Error Codes.

ID	Error Message
201	Permission denied
401	Parameter error. Possible causes: 1. Mandatory parameters are left unspecified; 2. Incorrect parameter types; 3. Parameter verification failed.
14000011	System inner fail.

Example

For details about how to create a phAccessHelper instance, see the example provided in photoAccessHelper.getPhotoAccessHelper.

import { dataSharePredicates } from '@kit.ArkData';

class MediaDataHandler implements photoAccessHelper.MediaAssetDataHandler<ArrayBuffer> {
  onDataPrepared(data: ArrayBuffer) {
    if (data === undefined) {
      console.error('Error occurred when preparing data');
      return;
    }
    console.info('on image data prepared');
  }
}

async function example(phAccessHelper: photoAccessHelper.PhotoAccessHelper, context: Context) {
  console.info('requestImageData');
  let predicates: dataSharePredicates.DataSharePredicates = new dataSharePredicates.DataSharePredicates();
  let fetchOptions: photoAccessHelper.FetchOptions = {
    fetchColumns: [],
    predicates: predicates
  };
  let requestOptions: photoAccessHelper.RequestOptions = {
    deliveryMode: photoAccessHelper.DeliveryMode.HIGH_QUALITY_MODE,
  }
  const handler = new MediaDataHandler();

  phAccessHelper.getAssets(fetchOptions, async (err, fetchResult) => {
      console.info('fetchResult success');
      let photoAsset: photoAccessHelper.PhotoAsset = await fetchResult.getFirstObject();
      if (photoAsset === undefined) {
      console.error('requestImageData photoAsset is undefined');
      return;
    }
      await photoAccessHelper.MediaAssetManager.requestImageData(context, photoAsset, requestOptions, handler);
      console.info('requestImageData successfully');
  });
}

requestMovingPhoto¹²⁺

static requestMovingPhoto(context: Context, asset: PhotoAsset, requestOptions: RequestOptions, dataHandler: MediaAssetDataHandler<MovingPhoto>): Promise<string>

Requests a moving photo object, which can be used to request the asset data of the moving photo. This API uses a promise to return the result.

System capability: SystemCapability.FileManagement.PhotoAccessHelper.Core

Required permissions: ohos.permission.READ_IMAGEVIDEO

• When this API is called in picker mode to request moving photos, the ohos.permission.READ_IMAGEVIDEO permission is not required. For details, see Obtaining an Image or Video by URI.
• For moving photos saved to the media library by this application, the application can access them without the ohos.permission.READ_IMAGEVIDEO permission.

Parameters

Name	Type	Mandatory	Description
context	Context	Yes	Context of the ability instance.
asset	PhotoAsset	Yes	Image to request.
requestOptions	RequestOptions	Yes	Options for requesting the image.
dataHandler	MediaAssetDataHandler<MovingPhoto>	Yes	Media asset handler, which invokes a callback to return the image when the requested image is ready.

Return value

Type	Description
Promise<string>	Promise used to return the request ID, which can be used in cancelRequest to cancel a request.

Error codes

For details about the error codes, see Universal Error Codes and File Management Error Codes.

ID	Error Message
201	Permission denied
401	Parameter error. Possible causes: 1. Mandatory parameters are left unspecified; 2. Incorrect parameter types; 3. Parameter verification failed.
801	Capability not supported.
14000011	System inner fail

Example

For details about how to create a phAccessHelper instance, see the example provided in photoAccessHelper.getPhotoAccessHelper.

import { dataSharePredicates } from '@kit.ArkData';

class MovingPhotoHandler implements photoAccessHelper.MediaAssetDataHandler<photoAccessHelper.MovingPhoto> {
  async onDataPrepared(movingPhoto: photoAccessHelper.MovingPhoto) {
    if (movingPhoto === undefined) {
      console.error('Error occurred when preparing data');
      return;
    }
    console.info("moving photo acquired successfully, uri: " + movingPhoto.getUri());
  }
}

async function example(phAccessHelper: photoAccessHelper.PhotoAccessHelper, context: Context) {
  let predicates: dataSharePredicates.DataSharePredicates = new dataSharePredicates.DataSharePredicates();
  predicates.equalTo(photoAccessHelper.PhotoKeys.PHOTO_SUBTYPE, photoAccessHelper.PhotoSubtype.MOVING_PHOTO);
  let fetchOptions: photoAccessHelper.FetchOptions = {
    fetchColumns: [],
    predicates: predicates
  };
  // Ensure that there are moving photos in Gallery.
  let assetResult: photoAccessHelper.FetchResult<photoAccessHelper.PhotoAsset> = await phAccessHelper.getAssets(fetchOptions);
  let asset: photoAccessHelper.PhotoAsset = await assetResult.getFirstObject();
  let requestOptions: photoAccessHelper.RequestOptions = {
    deliveryMode: photoAccessHelper.DeliveryMode.FAST_MODE,
  }
  const handler = new MovingPhotoHandler();
  try {
    let requestId: string = await photoAccessHelper.MediaAssetManager.requestMovingPhoto(context, asset, requestOptions, handler);
    console.info("moving photo requested successfully, requestId: " + requestId);
  } catch (err) {
    console.error(`failed to request moving photo, error code is ${err.code}, message is ${err.message}`);
  }
}

requestVideoFile¹²⁺

static requestVideoFile(context: Context, asset: PhotoAsset, requestOptions: RequestOptions, fileUri: string, dataHandler: MediaAssetDataHandler<boolean>): Promise<string>

Requests a video and saves it to the specified sandbox directory. This API uses a promise to return the result.

System capability: SystemCapability.FileManagement.PhotoAccessHelper.Core

Required permissions: ohos.permission.READ_IMAGEVIDEO

• When this API is called in picker mode to request video resources and save them to the specified sandbox directory, the ohos.permission.READ_IMAGEVIDEO permission is not required. For details, see Obtaining an Image or Video by URI.
• For video resources saved to the media library by this application, the application can access them without the ohos.permission.READ_IMAGEVIDEO permission.

Parameters

Name	Type	Mandatory	Description
context	Context	Yes	Context of the ability instance.
asset	PhotoAsset	Yes	Image to request.
requestOptions	RequestOptions	Yes	Options for requesting the video asset.
fileUri	string	Yes	URI of the sandbox directory, to which the requested video asset is to be saved. Example: 'file://com.example.temptest/data/storage/el2/base/haps/entry/files/test.mp4'.
dataHandler	MediaAssetDataHandler<boolean>	Yes	Media asset handler. When the requested video is written to the specified directory, a callback is triggered. If the video is successfully written, true is returned. Otherwise, false is returned.

Return value

Type	Description
Promise<string>	Promise used to return the request ID, which can be used in cancelRequest to cancel a request.

Error codes

For details about the error codes, see Universal Error Codes and File Management Error Codes.

ID	Error Message
201	Permission denied
401	Parameter error. Possible causes: 1. Mandatory parameters are left unspecified; 2. Incorrect parameter types; 3. Parameter verification failed.
801	Capability not supported.
14000011	System inner fail.

Example

For details about how to create a phAccessHelper instance, see the example provided in photoAccessHelper.getPhotoAccessHelper.

import { dataSharePredicates } from '@kit.ArkData';

class MediaDataHandler implements photoAccessHelper.MediaAssetDataHandler<boolean> {
    onDataPrepared(data: boolean) {
        console.info('on video request status prepared');
    }
}

async function example(phAccessHelper: photoAccessHelper.PhotoAccessHelper, context: Context) {
  console.info('requestVideoFile');
  let predicates: dataSharePredicates.DataSharePredicates = new dataSharePredicates.DataSharePredicates();
  let fetchOptions: photoAccessHelper.FetchOptions = {
    fetchColumns: [],
    predicates: predicates
  };
  let requestOptions: photoAccessHelper.RequestOptions = {
    deliveryMode: photoAccessHelper.DeliveryMode.HIGH_QUALITY_MODE,
  }
  const handler = new MediaDataHandler();
  let fileUri = 'file://com.example.temptest/data/storage/el2/base/haps/entry/files/test.mp4';
  phAccessHelper.getAssets(fetchOptions, async (err, fetchResult) => {
      console.info('fetchResult success');
      let photoAsset: photoAccessHelper.PhotoAsset = await fetchResult.getFirstObject();
      await photoAccessHelper.MediaAssetManager.requestVideoFile(context, photoAsset, requestOptions, fileUri, handler);
      console.info('requestVideoFile successfully');
  });
}

cancelRequest¹²⁺

static cancelRequest(context: Context, requestId: string): Promise<void>

Cancels a request for the asset, the callback of which has not been triggered yet. This API uses a promise to return the result.

System capability: SystemCapability.FileManagement.PhotoAccessHelper.Core

Required permissions: ohos.permission.READ_IMAGEVIDEO

Parameters

Name	Type	Mandatory	Description
context	Context	Yes	Context of the ability instance.
requestId	string	Yes	ID of the request to cancel. It is a valid request ID returned by requestImage.

Return value

Type	Description
Promise<void>	Promise that returns no value.

Error codes

For details about the error codes, see Universal Error Codes and File Management Error Codes.

ID	Error Message
201	Permission denied
401	Parameter error. Possible causes: 1. Mandatory parameters are left unspecified; 2. Incorrect parameter types; 3. Parameter verification failed.
14000011	System inner fail

Example

import { dataSharePredicates } from '@kit.ArkData';

async function example(context: Context) {
  try {
    let requestId: string = 'xxx-xxx'; // A valid requestId returned by APIs such as requestImage() must be used.
    await photoAccessHelper.MediaAssetManager.cancelRequest(context, requestId);
    console.info("request cancelled successfully");
  } catch (err) {
    console.error(`cancelRequest failed with error: ${err.code}, ${err.message}`);
  }
}

loadMovingPhoto¹²⁺

static loadMovingPhoto(context: Context, imageFileUri: string, videoFileUri: string): Promise<MovingPhoto>

Loads a moving photo in the application sandbox. This API uses a promise to return the result.

Atomic service API: This API can be used in atomic services since API version 14.

System capability: SystemCapability.FileManagement.PhotoAccessHelper.Core

Parameters

Name	Type	Mandatory	Description
context	Context	Yes	AbilityContext or UIExtensionContext instance.
imageFileUri	string	Yes	URI of the image file of the moving photo in the application sandbox. Example: 'file://com.example.temptest/data/storage/el2/base/haps/ImageFile.jpg'.
videoFileUri	string	Yes	URI of the video file of the moving photo in the application sandbox. Example: 'file://com.example.temptest/data/storage/el2/base/haps/VideoFile.mp4'.

Return value

Type	Description
Promise<MovingPhoto>	Promise used to return the MovingPhoto instance.

Error codes

For details about the error codes, see Universal Error Codes and File Management Error Codes.

ID	Error Message
401	Parameter error. Possible causes: 1. Mandatory parameters are left unspecified; 2. Incorrect parameter types; 3. Parameter verification failed.
14000011	Internal system error.

Example

async function example(context: Context) {
  try {
    let imageFileUri: string = 'file://com.example.temptest/data/storage/el2/base/haps/ImageFile.jpg'; // Image URI of the moving photo in the application sandbox.
    let videoFileUri: string = 'file://com.example.temptest/data/storage/el2/base/haps/VideoFile.mp4'; // Video URI of the moving photo in the application sandbox.
    let movingPhoto: photoAccessHelper.MovingPhoto = await photoAccessHelper.MediaAssetManager.loadMovingPhoto(context, imageFileUri, videoFileUri);
  } catch (err) {
    console.error(`loadMovingPhoto failed with error: ${err.code}, ${err.message}`);
  }
}

quickRequestImage¹³⁺

static quickRequestImage(context: Context, asset: PhotoAsset, requestOptions: RequestOptions, dataHandler: QuickImageDataHandler<image.Picture>): Promise<string>

Requests an image quickly. This API uses a promise to return the result.

System capability: SystemCapability.FileManagement.PhotoAccessHelper.Core

Required permissions: ohos.permission.READ_IMAGEVIDEO

• When this API is called in picker mode to request image resources, the ohos.permission.READ_IMAGEVIDEO permission is not required. For details, see Obtaining an Image or Video by URI.

Parameters

Name	Type	Mandatory	Description
context	Context	Yes	Context of the ability instance.
asset	PhotoAsset	Yes	Image to request.
requestOptions	RequestOptions	Yes	Options for requesting the image.
dataHandler	QuickImageDataHandler<image.Picture>	Yes	Media asset handler, which invokes a callback to return the image when the requested image is ready.

Return value

Type	Description
Promise<string>	Promise used to return the request ID, which can be used in cancelRequest to cancel a request.

Error codes

For details about the error codes, see Universal Error Codes and File Management Error Codes.

ID	Error Message
201	Permission denied
401	Parameter error. Possible causes: 1. Mandatory parameters are left unspecified; 2. Incorrect parameter types; 3. Parameter verification failed.
14000011	Internal system error.

Example

For details about how to create a phAccessHelper instance, see the example provided in photoAccessHelper.getPhotoAccessHelper.

import { dataSharePredicates } from '@kit.ArkData';
import { image } from '@kit.ImageKit';

class MediaHandler implements photoAccessHelper.QuickImageDataHandler<image.Picture> {
  onDataPrepared(data: image.Picture, imageSource: image.ImageSource, map: Map<string, string>) {
    console.info('on image data prepared');
  }
}

async function example(context: Context) {
  console.info('quickRequestImage');
  let predicates: dataSharePredicates.DataSharePredicates = new dataSharePredicates.DataSharePredicates();
  let fetchOptions: photoAccessHelper.FetchOptions = {
    fetchColumns: [],
    predicates: predicates
  };
  let requestOptions: photoAccessHelper.RequestOptions = {
    deliveryMode: photoAccessHelper.DeliveryMode.HIGH_QUALITY_MODE,
  }
  const handler = new MediaHandler();
  let phAccessHelper = photoAccessHelper.getPhotoAccessHelper(context);
  phAccessHelper.getAssets(fetchOptions, async (err, fetchResult) => {
      console.info('fetchResult success');
      let photoAsset: photoAccessHelper.PhotoAsset = await fetchResult.getFirstObject();
      await photoAccessHelper.MediaAssetManager.quickRequestImage(context, photoAsset, requestOptions, handler);
      console.info('quickRequestImage successfully');
  });
}

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