POST request with a simple string in body with Alamofire

how is it possible to send a POST request with a simple string in the HTTP body with Alamofire in my iOS app?

As default Alamofire needs parameters for a request:

Alamofire.request(.POST, "http://mywebsite.com/post-request", parameters: ["foo": "bar"])

These parameters contain key-value-pairs. But I don't want to send a request with a key-value string in the HTTP body.

I mean something like this:

Alamofire.request(.POST, "http://mywebsite.com/post-request", body: "myBodyString")

Your example Alamofire.request(.POST, "http://mywebsite.com/post-request", parameters: ["foo": "bar"]) already contains "foo=bar" string as its body. But if you really want string with custom format. You can do this:

Alamofire.request(.POST, "http://mywebsite.com/post-request", parameters: [:], encoding: .Custom({
            (convertible, params) in
            var mutableRequest = convertible.URLRequest.copy() as NSMutableURLRequest
            mutableRequest.HTTPBody = "myBodyString".dataUsingEncoding(NSUTF8StringEncoding, allowLossyConversion: false)
            return (mutableRequest, nil)
        }))

Note: parameters should not be nil

UPDATE (Alamofire 4.0, Swift 3.0):

In Alamofire 4.0 API has changed. So for custom encoding we need value/object which conforms to ParameterEncoding protocol.

extension String: ParameterEncoding {
    
    public func encode(_ urlRequest: URLRequestConvertible, with parameters: Parameters?) throws -> URLRequest {
        var request = try urlRequest.asURLRequest()
        request.httpBody = data(using: .utf8, allowLossyConversion: false)
        return request
    }
    
}

Alamofire.request("http://mywebsite.com/post-request", method: .post, parameters: [:], encoding: "myBody", headers: [:])

You can do this:

1. I created a separated request Alamofire object.

2. Convert string to Data

3. Put in httpBody the data

   var request = URLRequest(url: URL(string: url)!)
   request.httpMethod = HTTPMethod.post.rawValue
   request.setValue("application/json", forHTTPHeaderField: "Content-Type")
   
   let pjson = attendences.toJSONString(prettyPrint: false)
   let data = (pjson?.data(using: .utf8))! as Data
   
   request.httpBody = data
   
   Alamofire.request(request).responseJSON { (response) in
       
       
       print(response)
       
   }
   

If you use Alamofire, it is enough to set encoding type to URLEncoding.httpBody

With that, you can send your data as a string in the httpbody although you defined it as json in your code.

It worked for me..

Updated for Badr Filali's question:

var url = "http://..."
let _headers : HTTPHeaders = ["Content-Type":"application/x-www-form-urlencoded"]
let params : Parameters = ["grant_type":"password","username":"mail","password":"pass"]

let url =  NSURL(string:"url" as String)

request(url, method: .post, parameters: params, encoding: URLEncoding.httpBody, headers: _headers).responseJSON(
    completionHandler: { response in response
        let jsonResponse = response.result.value as! NSDictionary
        
        if jsonResponse["access_token"] != nil
        {
            access_token = String(describing: jsonResponse["accesstoken"]!)
        }
    })

I modified @Silmaril's answer to extend Alamofire's Manager. This solution uses EVReflection to serialize an object directly:

//Extend Alamofire so it can do POSTs with a JSON body from passed object
extension Alamofire.Manager {
    public class func request(
        method: Alamofire.Method,
        _ URLString: URLStringConvertible,
          bodyObject: EVObject)
        -> Request
    {
        return Manager.sharedInstance.request(
            method,
            URLString,
            parameters: [:],
            encoding: .Custom({ (convertible, params) in
                let mutableRequest = convertible.URLRequest.copy() as! NSMutableURLRequest
                mutableRequest.HTTPBody = bodyObject.toJsonString().dataUsingEncoding(NSUTF8StringEncoding, allowLossyConversion: false)
                return (mutableRequest, nil)
            })
        )
    }
}

Then you can use it like this:

Alamofire.Manager.request(.POST, endpointUrlString, bodyObject: myObjectToPost)

Based on Illya Krit's answer

Details

• Xcode Version 10.2.1 (10E1001)
• Swift 5
• Alamofire 4.8.2

Solution

import Alamofire

struct BodyStringEncoding: ParameterEncoding {

    private let body: String

    init(body: String) { self.body = body }

    func encode(_ urlRequest: URLRequestConvertible, with parameters: Parameters?) throws -> URLRequest {
        guard var urlRequest = urlRequest.urlRequest else { throw Errors.emptyURLRequest }
        guard let data = body.data(using: .utf8) else { throw Errors.encodingProblem }
        urlRequest.httpBody = data
        return urlRequest
    }
}

extension BodyStringEncoding {
    enum Errors: Error {
        case emptyURLRequest
        case encodingProblem
    }
}

extension BodyStringEncoding.Errors: LocalizedError {
    var errorDescription: String? {
        switch self {
            case .emptyURLRequest: return "Empty url request"
            case .encodingProblem: return "Encoding problem"
        }
    }
}

Usage

Alamofire.request(url, method: .post, parameters: nil, encoding: BodyStringEncoding(body: text), headers: headers).responseJSON { response in
     print(response)
}

If you want to post string as raw body in request

return Alamofire.request(.POST, "http://mywebsite.com/post-request" , parameters: [:], encoding: .Custom({
            (convertible, params) in
            let mutableRequest = convertible.URLRequest.copy() as! NSMutableURLRequest
            
            let data = ("myBodyString" as NSString).dataUsingEncoding(NSUTF8StringEncoding)
            mutableRequest.HTTPBody = data
            return (mutableRequest, nil)
        }))

I have done it for array from strings. This solution is adjusted for string in body.

The "native" way from Alamofire 4:

struct JSONStringArrayEncoding: ParameterEncoding {
    private let myString: String
    
    init(string: String) {
        self.myString = string
    }
    
    func encode(_ urlRequest: URLRequestConvertible, with parameters: Parameters?) throws -> URLRequest {
        var urlRequest = urlRequest.urlRequest
        
        let data = myString.data(using: .utf8)!
        
        if urlRequest?.value(forHTTPHeaderField: "Content-Type") == nil {
            urlRequest?.setValue("application/json", forHTTPHeaderField: "Content-Type")
        }
        
        urlRequest?.httpBody = data
        
        return urlRequest!
    }
}

And then make your request with:

Alamofire.request("your url string", method: .post, parameters: [:], encoding: JSONStringArrayEncoding.init(string: "My string for body"), headers: [:])

I've used answer of @afrodev as reference. In my case I take parameter to my function as string that have to be posted in request. So, here is the code:

func defineOriginalLanguage(ofText: String) {
    let text =  ofText
    let stringURL = basicURL + "identify?version=2018-05-01"
    let url = URL(string: stringURL)
    
    var request = URLRequest(url: url!)
    request.httpMethod = HTTPMethod.post.rawValue
    request.setValue("text/plain", forHTTPHeaderField: "Content-Type")
    request.httpBody = text.data(using: .utf8)
    
    Alamofire.request(request)
        .responseJSON { response in
            print(response)
    }
}

func paramsFromJSON(json: String) -> [String : AnyObject]?
{
    let objectData: NSData = (json.dataUsingEncoding(NSUTF8StringEncoding))!
    var jsonDict: [ String : AnyObject]!
    do {
        jsonDict = try NSJSONSerialization.JSONObjectWithData(objectData, options: .MutableContainers) as! [ String : AnyObject]
        return jsonDict
    } catch {
        print("JSON serialization failed:  \(error)")
        return nil
    }
}

let json = Mapper().toJSONString(loginJSON, prettyPrint: false)
    
Alamofire.request(.POST, url + "/login", parameters: paramsFromJSON(json!), encoding: .JSON)

My case, posting alamofire with content-type: "Content-Type":"application/x-www-form-urlencoded", I had to change encoding of alampfire post request

from : JSONENCODING.DEFAULT to: URLEncoding.httpBody

here:

let url = ServicesURls.register_token()
    let body = [        "UserName": "Minus28",        "grant_type": "password",        "Password": "1a29fcd1-2adb-4eaa-9abf-b86607f87085",         "DeviceNumber": "e9c156d2ab5421e5",          "AppNotificationKey": "test-test-test",        "RegistrationEmail": email,        "RegistrationPassword": password,        "RegistrationType": 2        ] as [String : Any]
    
    
    Alamofire.request(url, method: .post, parameters: body, encoding: URLEncoding.httpBody , headers: setUpHeaders()).log().responseJSON { (response) in

let parameters = ["foo": "bar"]
              
    // All three of these calls are equivalent
    AF.request("https://httpbin.org/post", method: .post, parameters: parameters)
    AF.request("https://httpbin.org/post", method: .post, parameters: parameters, encoder: URLEncodedFormParameterEncoder.default)
    AF.request("https://httpbin.org/post", method: .post, parameters: parameters, encoder: URLEncodedFormParameterEncoder(destination: .httpBody))
    
    

Xcode 8.X , Swift 3.X

Easy Use;

 let params:NSMutableDictionary? = ["foo": "bar"];
            let ulr =  NSURL(string:"http://mywebsite.com/post-request" as String)
            let request = NSMutableURLRequest(url: ulr! as URL)
            request.httpMethod = "POST"
            request.setValue("application/json", forHTTPHeaderField: "Content-Type")
            let data = try! JSONSerialization.data(withJSONObject: params!, options: JSONSerialization.WritingOptions.prettyPrinted)

            let json = NSString(data: data, encoding: String.Encoding.utf8.rawValue)
            if let json = json {
                print(json)
            }
            request.httpBody = json!.data(using: String.Encoding.utf8.rawValue);


            Alamofire.request(request as! URLRequestConvertible)
                .responseJSON { response in
                    // do whatever you want here
                   print(response.request)  
                   print(response.response) 
                   print(response.data) 
                   print(response.result)

            }