What HTTP methods are typically used in web scraping with Swift?

When web scraping with Swift, or any other language for that matter, the two primary HTTP methods used are GET and POST.

1. GET Method: This method is used to request data from a specified resource. In the context of web scraping, you'd use a GET request to fetch the HTML content of the page you intend to scrape.

2. POST Method: This method is used to send data to a server to create/update a resource. While not as common as GET for scraping tasks, POST requests are sometimes necessary when dealing with web forms, logins, or sessions where you need to send data to the server before getting the right page to scrape.

Here's a basic example of how you might use Swift to perform a GET request for web scraping purposes:

import Foundation

let url = URL(string: "http://example.com")!
let task = URLSession.shared.dataTask(with: url) { data, response, error in
    if let error = error {
        print("Client error: \(error)")
        return
    }

    guard let httpResponse = response as? HTTPURLResponse,
          (200...299).contains(httpResponse.statusCode) else {
        print("Server error")
        return
    }

    if let mimeType = httpResponse.mimeType, mimeType == "text/html",
       let data = data,
       let string = String(data: data, encoding: .utf8) {
        // This is where the scraping happens
        print(string)
    }
}

task.resume()

In this Swift code snippet, we use URLSession to create a simple GET request that fetches the HTML content of http://example.com. The response is then converted into a String which would be the starting point for parsing and scraping the desired data.

For POST requests, you would use a similar process but with additional steps to include the necessary data in the request:

import Foundation

let url = URL(string: "http://example.com/login")!
var request = URLRequest(url: url)
request.httpMethod = "POST"
let postString = "username=user&password=pass" // Replace with appropriate form data
request.httpBody = postString.data(using: .utf8)

let task = URLSession.shared.dataTask(with: request) { data, response, error in
    if let error = error {
        print("Client error: \(error)")
        return
    }

    guard let httpResponse = response as? HTTPURLResponse,
          (200...299).contains(httpResponse.statusCode) else {
        print("Server error")
        return
    }

    if let mimeType = httpResponse.mimeType, mimeType == "text/html",
       let data = data,
       let string = String(data: data, encoding: .utf8) {
        // This is where the scraping happens after a successful login
        print(string)
    }
}

task.resume()

In this example, we're setting up a POST request with a body that includes form data for a login process. Upon a successful login, the server would likely return a session cookie for subsequent requests or redirect you to the page that you're interested in scraping.

Keep in mind that web scraping should be done responsibly and ethically. You should always check a website's robots.txt file and terms of service to ensure that you're allowed to scrape their pages. Also, be mindful not to overload the website's servers with your requests.