Add POST,PUT,DELETE request class for swift

Question

I have create a client service class to make call GET request from web api. I tried to extended but have more web method POST,PUT,Delete.I don't find good example in how to create POST,PUT,Delete using swift closure.I just want to ask how to add POST,PUT,Delete to client service?

import Foundation

class ClientService{

    func getClients(searchstring:String,pageNumber:Int,callBack:(NSArray)->()){
        request("\(_settings.baseUrl)Client/\(searchstring)/\(String(pageNumber))/rrn/brns", callBack: callBack)
    }

    func request(url:String,callBack:(NSArray)->()){
        let nsURL = NSURL(string:url);
        let task = NSURLSession.sharedSession().dataTaskWithURL(nsURL!){
            (data,response,error) in
            do {
                let response = try NSJSONSerialization.JSONObjectWithData(data!, options:  NSJSONReadingOptions.MutableContainers) as! NSArray
                callBack(response)
            } catch let error as NSError {
                print("json error: \(error.localizedDescription)")
            }
        }
        task.resume()
    }

    init(){
        self._settings = Settings();
    }

    var _settings:Settings!;
}

Answer 1

You are on the right track. I make a separate function for get, post, put, delete etc. But you could make them in a one function if you want.

Bear in mind, this code is just to illustrate how to do it. You will need to modify it for your needs.

func request(url:String, method: String, params: [String: String], completion: ([AnyObject])->() ){
    if let nsURL = NSURL(string:url) {
        let request = NSMutableURLRequest(URL: nsURL)
        if method == "POST" {
            // convert key, value pairs into param string
            postString = params.map { "\($0.0)=\($0.1)" }.joinWithSeparator("&")
            request.HTTPMethod = "POST"
            request.HTTPBody = postString.dataUsingEncoding(NSUTF8StringEncoding)            
        }
        else if method == "GET" {
            postString = params.map { "\($0.0)=\($0.1)" }.joinWithSeparator("&")
            request.HTTPMethod = "GET"
        }
        else if method == "PUT" {
            putString = params.map { "\($0.0)=\($0.1)" }.joinWithSeparator("&")
            request.HTTPMethod = "PUT"
            request.HTTPBody = putString.dataUsingEncoding(NSUTF8StringEncoding)                        
        }
        // Add other verbs here

        let task = NSURLSession.sharedSession().dataTaskWithRequest(request) {
            (data, response, error) in
            do {

                // what happens if error is not nil? 
                // That means something went wrong.

                // Make sure there really is some data
                if let data = data {
                    let response = try NSJSONSerialization.JSONObjectWithData(data, options:  NSJSONReadingOptions.MutableContainers) 
                    completion(response)                    
                }
                else {
                    // Data is nil.
                }
            } catch let error as NSError {
                print("json error: \(error.localizedDescription)")
            }
        }
        task.resume()            
    }
    else{
        // Could not make url. Is the url bad?
        // You could call the completion handler (callback) here with some value indicating an error
    }    
}

Call it like this:

request("http://somedomain.etc", "POST", ["key1" : "value1", "key2", "values2"]) { 
    (result) in 
    // Handle result here.
}

You will note that I eliminated NSArray. [AnyObject] is the Swift way to do this.

I recommend that you add some sort of error indicator in the completion handler. That would let you detect that something went wrong and handle it.

Be very cautious when using ! to unwrap variables. This is the most common reason for apps crashing.