Swift : How to remember cookies for further http requests

In Swift, storing cookies for subsequent HTTP requests can be achieved through the following steps:

1. Using URLSession for network requests

First, utilize URLSession to make network requests. URLSession's configuration with HTTPCookieStorage automatically handles cookies from the server and uses them in subsequent requests.

2. Configuring URLSession

When creating URLSession, configure its configuration to allow accepting and sending cookies. This can be done by setting HTTPCookieAcceptPolicy to .always.

swift
let config = URLSessionConfiguration.default
config.httpCookieAcceptPolicy = .always
config.httpShouldSetCookies = true
let session = URLSession(configuration: config)

3. Initiating requests and handling responses

Use the configured session to make requests. Once the server response includes cookies, they are automatically saved to HTTPCookieStorage.

swift
if let url = URL(string: "https://example.com/login") {
    var request = URLRequest(url: url)
    request.httpMethod = "POST"
    let task = session.dataTask(with: request) { data, response, error in
        // Handle server response
    }
    task.resume()
}

4. Verifying cookie storage

You can verify if cookies are stored by checking HTTPCookieStorage.

swift
if let cookies = HTTPCookieStorage.shared.cookies {
    for cookie in cookies {
        print("$\{cookie.name} = $\{cookie.value}")
    }
}

5. Subsequent requests

In subsequent requests, URLSession automatically includes previously stored cookies as long as you use the same session or configure a new session with the same HTTPCookieStorage.

Example: Maintaining Login State Suppose after a user logs in, you want to maintain their login state for all subsequent requests. Ensure cookies are saved after a successful login, and URLSession will automatically include these cookies in subsequent requests to maintain the login state.

swift
// Login request
func login() {
    if let url = URL(string: "https://example.com/login") {
        var request = URLRequest(url: url)
        request.httpMethod = "POST"
        let task = session.dataTask(with: request) { [weak self] data, response, error in
            // After login, proceed with other authenticated requests
            self?.fetchUserData()
        }
        task.resume()
    }
}

// Fetch user data
func fetchUserData() {
    if let url = URL(string: "https://example.com/userdata") {
        let request = URLRequest(url: url)
        let task = session.dataTask(with: request) { data, response, error in
            // Handle user data
        }
        task.resume()
    }
}

By following these steps, you can effectively manage and use cookies in Swift to maintain HTTP request states.