DSDirectoryFetcher

The DSDirectoryFetcher class is a utility class that retrieves a list of files from a specified directory based on certain criteria. It inherits from the DSProactiveImageSourceAdapter class.

Definition

Assembly: DynamsoftCaptureVisionBundle.xcframework

Objective-C
Swift

NS_SWIFT_NAME(DirectoryFetcher)
@interface DSDirectoryFetcher : DSProactiveImageSourceAdapter

class DirectoryFetcher : ProactiveImageSourceAdapter

Methods

Method	Description
`init`	Create an instance of DSDirectoryFetcher.
`setDirectory`	Sets the directory path and filter for the file search.
`setPages`	Set the pages to read.

The following methods are inherited from DSProactiveImageSourceAdapter.

Method	Description
`setImageFetchInterval`	Sets the time interval for the ImageSource to wait before attempting to fetch another image to put in the buffer.
`getImageFetchInterval`	Gets the time interval for the ImageSource to wait before attempting to fetch another image to put in the buffer.

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.

init

Create an instance of DSDirectoryFetcher.

Objective-C

Swift
- (instancetype)init;
init()

Return Value

An instance of DSDirectoryFetcher.

Code Snippet

Objective-C
Swift

DSDirectoryFetcher *fetcher = [[DSDirectoryFetcher alloc] init];

```
let fetcher = DirectoryFetcher()
```

setDirectory

Sets the directory path and filter for the file search.

Objective-C
Swift

- (BOOL)setDirectory:(NSString *)directoryPath
          filter:(NSString *)filter
       recursive:(BOOL)recursive
           error:(NSError * _Nullable * _Nullable)error;

func setDirectory(_ directoryPath: String, filter: String?, recursive: Bool) throws

Parameters

directoryPath: The directory path.

filter: A string that specifies file extensions. It determines which kinds of files to read. e.g “*.BMP;*.JPG;*.GIF”.

recursive: Specifies whether to load files recursively.

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

Error

Error Code	Value	Description
EC_READ_DIRECTORY_FAILED	-10064	Failed to read the directory.

Return Value

A BOOL value that indicates whether the directory is set successfully.

Code Snippet

Objective-C
Swift

NSError *error;
BOOL success = [fetcher setDirectory:directoryPath filter:nil recursive:YES error:&error];

do {
   try fetcher.setDirectory(directoryPath, filter: nil, recursive: true)
} catch {
   // Add your code to deal with exceptions.
}

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.