Is there a way to handle cookies and sessions with Kanna?

Kanna is a Swift library for parsing HTML and XML, mainly used in iOS and macOS development. It doesn't directly handle HTTP requests, cookies, or sessions, as it is not an HTTP client library; rather, it is a parsing library similar to Beautiful Soup in Python or Nokogiri in Ruby.

However, when web scraping, you often need to handle cookies and sessions to maintain state across multiple requests, especially when dealing with login sessions or any site that maintains user state. In Swift, you would typically handle cookies and sessions with URLSession rather than Kanna.

Here's a basic example of how you might use URLSession to handle cookies while using Kanna for parsing the HTML content in a Swift application:

import Foundation
import Kanna

// Create a URL session configuration
let config = URLSessionConfiguration.default
config.httpCookieAcceptPolicy = .always
config.httpShouldSetCookies = true

// Create a URL session with the configuration
let session = URLSession(configuration: config)

// Define the URL you want to make a request to
if let url = URL(string: "https://example.com/login") {
    var request = URLRequest(url: url)
    request.httpMethod = "POST"
    request.addValue("application/x-www-form-urlencoded", forHTTPHeaderField: "Content-Type")

    // Add your login parameters
    let params = "username=YOUR_USERNAME&password=YOUR_PASSWORD"
    request.httpBody = params.data(using: .utf8)

    // Perform the request
    let task = session.dataTask(with: request) { (data, response, error) in
        // Check for errors
        if let error = error {
            print("Error: \(error)")
            return
        }

        // Check if the response contains data
        guard let data = data else {
            print("No data received")
            return
        }

        // Use Kanna to parse the HTML content
        if let doc = try? HTML(html: data, encoding: .utf8) {
            // Parse your document here with Kanna
            for link in doc.xpath("//a | //link") {
                if let href = link["href"] {
                    print(href)
                }
            }
        }

        // To access and manage cookies, you can use HTTPCookieStorage
        if let httpResponse = response as? HTTPURLResponse,
            let url = httpResponse.url {
            let cookies = HTTPCookie.cookies(withResponseHeaderFields: httpResponse.allHeaderFields as! [String : String], for: url)
            for cookie in cookies {
                print("\(cookie.name) - \(cookie.value)")
                HTTPCookieStorage.shared.setCookie(cookie)
            }
        }
    }

    // Start the task
    task.resume()
}

// Run the loop to allow asynchronous tasks to complete
RunLoop.main.run()

In the above example, we configure a URLSession to accept and set cookies. We create a POST request to a login form, sending the username and password. After the request is made, we parse the HTML with Kanna and also print out the cookies received.

Please note that handling sessions and cookies is site-specific. Some sites might require additional headers, tokens (like CSRF), or cookies to be set in advance. Always ensure that you are in compliance with the website's terms of service when scraping.