php - HTTP Post Parameters are passed json encoded to $_POST

Question

I can't figure out how to properly send POST parameters.

My Swift 3:

let parameters = ["name": "thom", "password": "12345"] as Dictionary<String, String>
let url = URL(string: "https://mywebsite.com/test.php")!
let session = URLSession.shared
var request = URLRequest(url: url)
request.httpMethod = "POST"
do
{
    request.httpBody = try JSONSerialization.data(withJSONObject: parameters)
}
catch let error
{
    print(error.localizedDescription)
}
request.addValue("application/x-www-form-urlencoded", forHTTPHeaderField: "Content-Type")
request.addValue("application/json", forHTTPHeaderField: "Accept")
let task = session.dataTask(with: request as URLRequest, completionHandler: 
{
    data, response, error in
    guard error == nil else
    {
        print(error as Any)
        return
    }           
    guard let data = data else
    {
        return
    }
    do 
    {
        if let json = try JSONSerialization.jsonObject(with: data, options: .mutableContainers) as? [String: Any] 
        {
            print(json)
            print(json["post"]!)
        }
        else
        {
            print("no json")
        }
    }
    catch let error
    {
        print(error.localizedDescription)
    }
})
task.resume()

My PHP:

<?php
header('Content-Type: application/json');
if(empty($_POST)) echo json_encode(array('post'=>'empty'));
else echo json_encode($_POST+array('post'=>'not_empty'));
exit;

If I set the content-type header (in Swift) to application/json I get:

["post": empty]
empty

If I set it to application/x-www-form-urlencoded I get:

["{"name":"thom","password":"12345"}": , "post": not_empty]
not_empty

How do I send the dictionary to my server as $_POST key/value pairs, not as a json_encoded string?

Answer 1

You want to percent-escape the request into a x-www-form-urlencoded request, like so:

let parameters = ["name": "thom", "password": "12345"]
let url = URL(string: "https://mywebsite.com/test.php")!

var request = URLRequest(url: url)
request.httpMethod = "POST"
request.updateHttpBody(with: parameters)
request.setValue("application/x-www-form-urlencoded", forHTTPHeaderField: "Content-Type")

let task = session.dataTask(with: request) { data, response, error in
    guard let data = data, error == nil else {
        print("(error)")
        return
    }

    // handle response here
}
task.resume()

Where

extension URLRequest {

    /// Populate the `httpBody` of `application/x-www-form-urlencoded` request.
    ///
    /// - parameter parameters:   A dictionary of keys and values to be added to the request

    mutating func updateHttpBody(with parameters: [String : String]) {
        let parameterArray = parameters.map { (key, value) -> String in
            return "(key.addingPercentEncodingForQueryValue()!)=(value.addingPercentEncodingForQueryValue()!)"
        }
        httpBody = parameterArray.joined(separator: "&").data(using: .utf8)
    }
}

extension String {

    /// Percent escape value to be added to a HTTP request
    ///
    /// This percent-escapes all characters besides the alphanumeric character set and "-", ".", "_", and "*".
    /// This will also replace spaces with the "+" character as outlined in the application/x-www-form-urlencoded spec:
    ///
    /// http://www.w3.org/TR/html5/forms.html#application/x-www-form-urlencoded-encoding-algorithm
    ///
    /// - returns: Return percent escaped string.

    func addingPercentEncodingForQueryValue() -> String? {
        let generalDelimitersToEncode = ":#[]@?/"
        let subDelimitersToEncode = "!$&'()*+,;="

        var allowed = CharacterSet.urlQueryAllowed
        allowed.remove(charactersIn: "(generalDelimitersToEncode)(subDelimitersToEncode)")

        return addingPercentEncoding(withAllowedCharacters: allowed)?.replacingOccurrences(of: " ", with: "+")
    }
}