DSFileFetcher

The DSFileFetcher class is a utility class that partitions a multi-page image file into multiple independent ImageData objects. It inherits from the DSImageSourceAdapter class.

Definition

Assembly: DynamsoftCaptureVisionBundle.xcframework

Objective-C
Swift

@interface DSFileFetcher : DSImageSourceAdapter

class FileFetcher : DSImageSourceAdapter

Methods

Method	Description
`setFileWithPath`	Sets the file with a file path.
`setFileWithBytes`	Sets the file with file bytes.
`setFileWithBuffer`	Sets the file with a `DSImageData` object.
`setFileWithImage`	Sets the file with a `UIImage`.
`hasNextImageToFetch`	Whether there is a next image to fetch.
`getImage`	Get the image data of the image.
`setPages`	Set the pages to read.

The following methods & attributes are inherited from DSImageSourceAdapter.

Attributes	Type	Description
`bufferEmpty`	BOOL	The read only property determines whether the buffer is currently empty.
`bufferOverflowProtectionMode`	DSBufferOverflowProtectionMode	Sets the behavior for handling new incoming images when the buffer is full.
`colourChannelUsageType`	colourChannelUsageType	Sets the usage type for color channels in images.
`hasNextImageToFetch`	BOOL	Determines whether there are more images available to fetch.
`imageCount`	NSUInteger	The property defines the current number of images in the buffer.
`maxImageCount`	NSUInteger	The property defines the maximum number of images that can be buffered.

Method	Description
`addImageToBuffer`	Adds an image to the internal buffer.
`clearBuffer`	Clears all images from the buffer, resetting the state for new image fetching.
`getImage`	Get a buffered image. Implementing classes should return a Promise that resolves with an instance of `DSImageData`.
`hasImage`	Checks if an image with the specified ID is present in the buffer.
`setErrorListener`	Sets an error listener to receive notifications about errors that occur during image source operations.
`setNextImageToReturn`	Sets the processing priority of a specific image. This can affect the order in which images are returned by `getImage`.
`startFetching`	Start fetching images from the source to the Video Buffer of ImageSourceAdapter.
`stopFetching`	Stop fetching images from the source to the Video Buffer of ImageSourceAdapter.

setFileWithPath

Sets the file with a file path.

Objective-C
Swift

-(BOOL)setFileWithPath:(NSString *)filePath
             error:(NSError *_Nullable *_Nullable)error;

func setFileWithPath( _filePath: String) throws

Parameters

filePath: The file path.

error: An NSError pointer. If an error occurs, it will represent the error information.

Error

Error Code	Value	Description
EC_FILE_NOT_FOUND	-10005	The file is not found.
EC_FILE_TYPE_NOT_SUPPORTED	-10006	The file type is not supported.

setFileWithBytes

Sets the file with file bytes.

Objective-C
Swift

-(BOOL)setFileWithBytes:(NSData *)fileBytes
              error:(NSError *_Nullable *_Nullable)error;

func setFileWithBytes( _fileBytes: Data) throws

Parameters

fileBytes: The file bytes.

error: An NSError pointer. If an error occurs, it will represent the error information.

Error

Error Code	Value	Description
EC_NULL_POINTER	-10002	The fileBytes you input is null.

setFileWithBuffer

Sets the file with a DSImageData object.

Objective-C
Swift

-(BOOL)setFileWithBuffer:(DSImageData *)buffer
               error:(NSError *_Nullable *_Nullable)error;

func setFileWithBuffer( _buffer: ImageData) throws

Parameters

buffer: The image data.

error: An NSError pointer. If an error occurs, it will represent the error information.

Error

Error Code	Value	Description
EC_NULL_POINTER	-10002	The fileBytes you input is null.

setFileWithImage

Sets the file with a UIImage.

Objective-C
Swift

-(BOOL)setFileWithImage:(UIImage *)image
              error:(NSError *_Nullable *_Nullable)error;

func setFileWithImage( _image: UIImage) throws

Parameters

image: A UIImage.

error: An NSError pointer. If an error occurs, it will represent the error information.

Error

Error Code	Value	Description
EC_NULL_POINTER	-10002	The fileBytes you input is null.

hasNextImageToFetch

Whether there is a next image to fetch.

Objective-C
Swift

```
-(BOOL)hasNextImageToFetch;
```
```
func hasNextImageToFetch() -> Bool
```

Return Value

A bool value that indicates whether there is a next image to fetch.

setPages

Set the pages to read.

Objective-C
Swift

-(BOOL)setPages:(NSArray<NSNumber *> *)pages
      error:(NSError *_Nullable *_Nullable)error;

func setPages(_ pages: NSArray) throws -> BOOL

Parameters

pages: An array that contains all the pages to read.
error: An NSError pointer. If an error occurs, it will represent the error information.

Error

Error Code	Value	Description
EC_FILE_NOT_FOUND	-10005	File not found.
EC_FILE_TYPE_NOT_SUPPORTED	-10006	The file type is not supported.
EC_IMAGE_READ_FAILED	-10012	Failed to read the image.