[post] HTTP Request in Swift with POST method

In Swift 3 and later you can:

let url = URL(string: "http://www.thisismylink.com/postName.php")!
var request = URLRequest(url: url)
request.setValue("application/x-www-form-urlencoded", forHTTPHeaderField: "Content-Type")
request.httpMethod = "POST"
let parameters: [String: Any] = [
    "id": 13,
    "name": "Jack & Jill"
]
request.httpBody = parameters.percentEncoded()

let task = URLSession.shared.dataTask(with: request) { data, response, error in
    guard let data = data, 
        let response = response as? HTTPURLResponse, 
        error == nil else {                                              // check for fundamental networking error
        print("error", error ?? "Unknown error")
        return
    }

    guard (200 ... 299) ~= response.statusCode else {                    // check for http errors
        print("statusCode should be 2xx, but is \(response.statusCode)")
        print("response = \(response)")
        return
    }

    let responseString = String(data: data, encoding: .utf8)
    print("responseString = \(responseString)")
}

task.resume()

Where:

extension Dictionary {
    func percentEncoded() -> Data? {
        return map { key, value in
            let escapedKey = "\(key)".addingPercentEncoding(withAllowedCharacters: .urlQueryValueAllowed) ?? ""
            let escapedValue = "\(value)".addingPercentEncoding(withAllowedCharacters: .urlQueryValueAllowed) ?? ""
            return escapedKey + "=" + escapedValue
        }
        .joined(separator: "&")
        .data(using: .utf8)
    }
}

extension CharacterSet { 
    static let urlQueryValueAllowed: CharacterSet = {
        let generalDelimitersToEncode = ":#[]@" // does not include "?" or "/" due to RFC 3986 - Section 3.4
        let subDelimitersToEncode = "!$&'()*+,;="

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

This checks for both fundamental networking errors as well as high-level HTTP errors. This also properly percent escapes the parameters of the query.

Note, I used a name of Jack & Jill, to illustrate the proper x-www-form-urlencoded result of name=Jack%20%26%20Jill, which is “percent encoded” (i.e. the space is replaced with %20 and the & in the value is replaced with %26).


See previous revision of this answer for Swift 2 rendition.

Examples related to post

How to post query parameters with Axios? How can I add raw data body to an axios request? HTTP POST with Json on Body - Flutter/Dart How do I POST XML data to a webservice with Postman? How to set header and options in axios? Redirecting to a page after submitting form in HTML How to post raw body data with curl? How do I make a https post in Node Js without any third party module? How to convert an object to JSON correctly in Angular 2 with TypeScript Postman: How to make multiple requests at the same time

Examples related to swift

Make a VStack fill the width of the screen in SwiftUI Xcode 10.2.1 Command PhaseScriptExecution failed with a nonzero exit code Command CompileSwift failed with a nonzero exit code in Xcode 10 Convert Json string to Json object in Swift 4 iOS Swift - Get the Current Local Time and Date Timestamp Xcode 9 Swift Language Version (SWIFT_VERSION) How do I use Safe Area Layout programmatically? How can I use String substring in Swift 4? 'substring(to:)' is deprecated: Please use String slicing subscript with a 'partial range from' operator Safe Area of Xcode 9 The use of Swift 3 @objc inference in Swift 4 mode is deprecated?

Examples related to parameters

Stored procedure with default parameters AngularJS ui router passing data between states without URL C#: HttpClient with POST parameters HTTP Request in Swift with POST method In Swift how to call method with parameters on GCD main thread? How to pass parameters to maven build using pom.xml? Default Values to Stored Procedure in Oracle How do you run a .exe with parameters using vba's shell()? How to set table name in dynamic SQL query? How to pass parameters or arguments into a gradle task

Examples related to http-post

Passing headers with axios POST request How to post raw body data with curl? Send FormData with other field in AngularJS How do I POST a x-www-form-urlencoded request using Fetch? OkHttp Post Body as JSON What is the difference between PUT, POST and PATCH? HTTP Request in Swift with POST method Uploading file using POST request in Node.js Send POST request with JSON data using Volley AngularJS $http-post - convert binary to excel file and download

Examples related to httprequest

Http post and get request in angular 6 Postman: How to make multiple requests at the same time Adding header to all request with Retrofit 2 Understanding Chrome network log "Stalled" state Why is this HTTP request not working on AWS Lambda? Simulate a specific CURL in PostMan HTTP Request in Swift with POST method What are all the possible values for HTTP "Content-Type" header? How to get host name with port from a http or https request Why I get 411 Length required error?