iOS / Swift - Simple RestApi util class

RestApi.swift

class RestApi {

    class func post(request: NSMutableURLRequest, completion: (response: String?, json: AnyObject?) -> ()) {
        dataTask(request, method: "POST", completion: completion)
    }

    class func put(request: NSMutableURLRequest, completion: (response: String?, json: AnyObject?) -> ()) {
        dataTask(request, method: "PUT", completion: completion)
    }

    class func get(request: NSMutableURLRequest, completion: (response: String?, json: AnyObject?) -> ()) {
        dataTask(request, method: "GET", completion: completion)
    }

    class func dataTask(request: NSMutableURLRequest, method: String, completion: (response: String?, json: AnyObject?) -> ()) {
        request.HTTPMethod = method

        let session = NSURLSession(configuration: NSURLSessionConfiguration.defaultSessionConfiguration())

        session.dataTaskWithRequest(request) { (data, response, error) -> Void in
            if let data = data {
                let json = try? NSJSONSerialization.JSONObjectWithData(data, options: [])
                let response = String(data: data, encoding: NSUTF8StringEncoding)
                completion(response: response, json: json)
            } else {
                completion(response: "NSURLSessionTimeout", json: nil)
            }
            }.resume()
    }

    class func clientUrlRequest(path: String, params: [String: AnyObject]? = nil) -> NSMutableURLRequest {
        let request = NSMutableURLRequest(URL: NSURL(string: BaseURL.getFromEnvironment() + "\(path)")!)
        if let params = params {
            var paramString = ""
            for (key, value) in params {
                paramString += "\(key)=\(value)&"
            }

            request.setValue("application/x-www-form-urlencoded", forHTTPHeaderField: "Content-Type")
            request.HTTPBody = paramString.dataUsingEncoding(NSUTF8StringEncoding)
        }
        
        return request
    }

}