[ios] Swift GET request with parameters

I'm very new to swift, so I will probably have a lot of faults in my code but what I'm trying to achieve is send a GET request to a localhost server with paramters. More so I'm trying to achieve it given my function take two parameters baseURL:string,params:NSDictionary. I am not sure how to combine those two into the actual URLRequest ? Here is what I have tried so far

    func sendRequest(url:String,params:NSDictionary){
       let urls: NSURL! = NSURL(string:url)
       var request = NSMutableURLRequest(URL:urls)
       request.HTTPMethod = "GET"
       var data:NSData! =  NSKeyedArchiver.archivedDataWithRootObject(params)
       request.HTTPBody = data
       println(request)
       var session = NSURLSession.sharedSession()
       var task = session.dataTaskWithRequest(request, completionHandler:loadedData)
       task.resume()

    }

}

func loadedData(data:NSData!,response:NSURLResponse!,err:NSError!){
    if(err != nil){
        println(err?.description)
    }else{
        var jsonResult: NSDictionary = NSJSONSerialization.JSONObjectWithData(data, options: NSJSONReadingOptions.MutableContainers, error: nil) as NSDictionary
        println(jsonResult)

    }

}

I use:

let dictionary = ["method":"login_user",
                  "cel":mobile.text!
                  "password":password.text!] as  Dictionary<String,String>

for (key, value) in dictionary {
    data=data+"&"+key+"="+value
    }

request.HTTPBody = data.dataUsingEncoding(NSUTF8StringEncoding);

Use NSURLComponents to build your NSURL like this

var urlComponents = NSURLComponents(string: "https://www.google.de/maps/")!

urlComponents.queryItems = [
  NSURLQueryItem(name: "q", value: String(51.500833)+","+String(-0.141944)),
  NSURLQueryItem(name: "z", value: String(6))
]
urlComponents.URL // returns https://www.google.de/maps/?q=51.500833,-0.141944&z=6

font: https://www.ralfebert.de/snippets/ios/encoding-nsurl-get-parameters/

Swift 3:

extension URL {
    func getQueryItemValueForKey(key: String) -> String? {
        guard let components = NSURLComponents(url: self, resolvingAgainstBaseURL: false) else {
              return nil
        }

        guard let queryItems = components.queryItems else { return nil }
     return queryItems.filter {
                 $0.name.lowercased() == key.lowercased()
                 }.first?.value
    }
}

I used it to get the image name for UIImagePickerController in func imagePickerController(_ picker: UIImagePickerController, didFinishPickingMediaWithInfo info: [String : Any]):

var originalFilename = ""
if let url = info[UIImagePickerControllerReferenceURL] as? URL, let imageIdentifier = url.getQueryItemValueForKey(key: "id") {
    originalFilename = imageIdentifier + ".png"
    print("file name : \(originalFilename)")
}

This extension that @Rob suggested works for Swift 3.0.1

I wasn't able to compile the version he included in his post with Xcode 8.1 (8B62)

extension Dictionary {

    /// Build string representation of HTTP parameter dictionary of keys and objects
    ///
    /// :returns: String representation in the form of key1=value1&key2=value2 where the keys and values are percent escaped

    func stringFromHttpParameters() -> String {

        var parametersString = ""
        for (key, value) in self {
            if let key = key as? String,
               let value = value as? String {
                parametersString = parametersString + key + "=" + value + "&"
            }
        }
        parametersString = parametersString.substring(to: parametersString.index(before: parametersString.endIndex))
        return parametersString.addingPercentEncoding(withAllowedCharacters: .urlHostAllowed)!
    }

}

You can extend your Dictionary to only provide stringFromHttpParameter if both key and value conform to CustomStringConvertable like this

extension Dictionary where Key : CustomStringConvertible, Value : CustomStringConvertible {
  func stringFromHttpParameters() -> String {
    var parametersString = ""
    for (key, value) in self {
      parametersString += key.description + "=" + value.description + "&"
    }
    return parametersString
  }
}

this is much cleaner and prevents accidental calls to stringFromHttpParameters on dictionaries that have no business calling that method

I am using this, try it in playground. Define the base urls as Struct in Constants

struct Constants {

    struct APIDetails {
        static let APIScheme = "https"
        static let APIHost = "restcountries.eu"
        static let APIPath = "/rest/v1/alpha/"
    }
}

private func createURLFromParameters(parameters: [String:Any], pathparam: String?) -> URL {

    var components = URLComponents()
    components.scheme = Constants.APIDetails.APIScheme
    components.host   = Constants.APIDetails.APIHost
    components.path   = Constants.APIDetails.APIPath
    if let paramPath = pathparam {
        components.path = Constants.APIDetails.APIPath + "\(paramPath)"
    }
    if !parameters.isEmpty {
        components.queryItems = [URLQueryItem]()
        for (key, value) in parameters {
            let queryItem = URLQueryItem(name: key, value: "\(value)")
            components.queryItems!.append(queryItem)
        }
    }

    return components.url!
}

let url = createURLFromParameters(parameters: ["fullText" : "true"], pathparam: "IN")

//Result url= https://restcountries.eu/rest/v1/alpha/IN?fullText=true