Visalto

Visalto is a lightweight framework for asynchronous image loading from the web or a disk. It provides in-memory and disk caching functionalities. The basic image loading looks as follows

let url = URL(string: “example.com/test.jpg”)!

Visalto.shared.loadImage(with: url, completionQueue: .main) { result in

    switch result {
    case .failure(let error):
        print(error.localizedDescription)

    case .success(let image):
        // requested image is here
        break
    }	

}

The same interface may be used for loading an image from the disk and from the web.

For cancellation of an operation just call cancelLoading with the url that was used for its creation.

Visalto.shared.cancelLoading(for: url)

Possible customizations

There are numerous parameters available for the customization of image loading behaviour.

Set your own custom URL session for remote image downloading.

let myCustomURLSession: URLSession = ...
Visalto.shared.setURLSession(myCustomURLSession))

Set maximum concurrent loading operations

Visalto.shared.maxConcurrentLoadingsCount = 10

Set quality of service of image loading queue

Visalto.shared.qualityOfService = .userInteractive

Turn on/off a disk cache

Visalto.shared.useDiskCache = false

It is also possible to customize each image loading operation by providing

• quality of service
• priority in the queue
• url request cache policy
• url request timeout interval

Visalto.shared.loadImage(with: url,
                         qos: .userInteractive,
                         queuePriority: .high,
                         cachePolicy: .reloadIgnoringCacheData,
                         timeoutInterval: 20,
                         completionQueue: .main) { result in ... }

An associated project - VisaltoShowcase - demonstrates the usage of the framework.