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Update ui and ui image load from url in ios swift

Hello everyone junior dev here, I fetch data from server in background thread and update ui in main thread, it works but i also have separate ui image loader from url here:

extension UIImageView {
    func load(url: String) {
        guard let urlString = URL(string: url) else {return}
        DispatchQueue.global(qos: .background).async { [weak self] in
            if let data = try? Data(contentsOf: urlString) {
                if let image = UIImage(data: data) {
                    DispatchQueue.main.async {
                        self?.image = image
                    }
                }
            }
        }
    }
}

But when open screen first image loader above works and app freezes for seconds and then main ui (uiviews) update, both ui updates in main thread. How can I make it image load in main thread do not block uiview update? I want it to be like this: Ui updates and works, then when image is uploaded it should not freeze main ui updates.
Additional info: using combine to fetch data and uikit for design.
Thanks in advance!

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2

Answers


  1. 0

    Use URLSession

    extension UIImageView {
    func load(urlString: String) {
        guard let url = URL(string: urlString) else {return}
        
        let task = URLSession.shared.dataTask(with: url) { data, response, error in
            guard let data = data, error == nil else { return }
            
            DispatchQueue.main.async {
                self.image = UIImage(data: data)
            }
        }
        
        task.resume()
    }
}
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  2. 0

    I think you should create a static thread instead of calling DispatchQueue.global(qos: .background), for example:

    extension UIImageView {
static let loadingImageThread = DispatchQueue(label: "loadingImageThread", qos: .background ,attributes: .concurrent, autoreleaseFrequency: .workItem)
func load(url: String) {
    guard let urlString = URL(string: url) else {return}
    loadingImageThread.async { [weak self] in
        if let data = try? Data(contentsOf: urlString) {
            if let image = UIImage(data: data) {
                DispatchQueue.main.async {
                    self?.image = image
                }
            }
        }
    }
}

    }

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