CODEWITHSUNDEEP
iosswiftnsurlsession
Lê Khánh Vinh
Lê Khánh Vinh

Reputation: 2609

iOS Swift 3 create URLSession extension for synchronous and asynchronous request

I'm about to create an extension for URLSession in Swift 3 to create synchronous and asynchronous request. Here is my implementation

extension URLSession {
    func sendSynchronousRequest(request: URL, completionHandler: @escaping (Data?, URLResponse?, Error?) -> Void) {
        let semaphore = DispatchSemaphore(value: 0)

        let task = self.dataTask(with: request) { (data, response, error) in
            completionHandler(data,response,error)
            semaphore.signal()
        }
        task.resume()
        semaphore.wait(timeout: .distantFuture)
    }

    func sendAsynchronousRequest(request: URLRequest, completionHandler: @escaping (Data?, URLResponse?, Error?) -> Void) -> URLSessionDataTask {
        let task = self.dataTask(with: request) { data, response, error in
            completionHandler(data, response, error)
        }
        task.resume()
        return task
    }
}

I have Xcode suggest me to insert the @escaping to the function. I don't know whether the implementation is correct

I also have warning at this line:

enter image description here

Anyone know how to correct the extension?

Upvotes: 2

Views: 3793

Answers (1)

Daniel Poulsen
Daniel Poulsen

Reputation: 1456

I found this implementation but in swift1/2 can't remember. This is not my own. But i rewrote it in swift3. I just can't remember where i found it :/

func synchronousDataTaskWithURL(url: URL) -> (Data?, URLResponse?, Error?) {
    var data: Data?, response: URLResponse?, error: Error?

    let semaphore = DispatchSemaphore(value: 0)

    dataTask(with: url) {
        data = $0; response = $1; error = $2
        semaphore.signal()
        }.resume()

    semaphore.wait()

    return (data, response, error)
}

Upvotes: 12

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