Simple Class for making Rest API calls in swift.

RestService.swift

import Foundation
import UIKit

class RestService{
    
    /**
    GET respons from REST API.
    
    :param: reqUrl            URL of webservice.
    :param: completionHandler callback function, this will called once you get response.
    */
    func doGet(reqUrl:String, completionHandler:( NSURLResponse?, NSData?, NSError?) -> Void){
        
        //Create request from URL
        let urlStringByencoding = reqUrl.stringByAddingPercentEncodingWithAllowedCharacters(.URLHostAllowedCharacterSet())
        let url = NSURL(string: urlStringByencoding!)
        
        print(" Request URL : \(url!)")
        
        let cachePolicy = NSURLRequestCachePolicy.ReloadIgnoringLocalCacheData
        let request = NSMutableURLRequest(URL: url!, cachePolicy: cachePolicy, timeoutInterval: 20.0)
        request.HTTPMethod = "GET"
        
        //Set content type
        let contentType = "application/json"
        NSURLProtocol.setProperty(contentType, forKey: "Content-Type", inRequest: request)
        
        //You can add any header as below
        //request.setValue( "Value", forHTTPHeaderField: "header_key")
        
        // To make Asynchronous Request
        let queue:NSOperationQueue = NSOperationQueue()
        NSURLConnection.sendAsynchronousRequest(request, queue: queue, completionHandler: completionHandler )
        
        print("GET API called..." )
    }
    
    
    /**
    POST REST web-service
    
    :param: reqUrl            URL
    :param: requestData       STRING(PARAMETERS which you want to post to server)
    :param: completionHandler callback function, this will called once you get response.
    */
    func doPost(reqUrl:String, requestData:String, completionHandler:( NSURLResponse?, NSData?, NSError?) -> Void){
        
        //Create request from URL
        let url = NSURL(string: reqUrl)
        let cachePolicy = NSURLRequestCachePolicy.ReloadIgnoringLocalCacheData
        let request = NSMutableURLRequest(URL: url!, cachePolicy: cachePolicy, timeoutInterval: 20.0)
        request.HTTPMethod = "POST"
        
        //Set content type
        let contentType = "application/json"
        NSURLProtocol.setProperty(contentType, forKey: "Content-Type", inRequest: request)
        
        //You can add any header as below
        //request.setValue( "Value", forHTTPHeaderField: "header_key")
        
        // set data
        let requestBodyData = (requestData as NSString).dataUsingEncoding(NSUTF8StringEncoding)
        request.HTTPBody = requestBodyData
        
        // To make Asynchronous Request
        let queue:NSOperationQueue = NSOperationQueue()
        NSURLConnection.sendAsynchronousRequest(request,
            queue: queue,
            completionHandler: completionHandler) 
        /*
         // If you want to make annonymous request, you can use following code 
         // Just unblock this block
        { (response: NSURLResponse!, data: NSData!, error: NSError!) -> Void in
        // Your code here
        if error != nil {
        print(error.description)
        }
        else {
        //Converting data to String
        var jsonData : NSString = NSString(data:data, encoding:NSUTF8StringEncoding)
        
        // To cast from NSURLResponse to NSHTTPURLResponse for getting http status code
        let res = response as NSHTTPURLResponse
        let responseCode = res.statusCode
        print("Asynchronous Response: \(responseCode)" + " \nand data: \(jsonData)")
        }
        });
        */
        
        print("POST API called... " )
    }
    
    /**
    PUT API for UPDATE
    
    :param: reqUrl            URL OF WEBSERVICE
    :param: requestData       STRING(PARAMETERS which you want to post to server)
    :param: completionHandler callback function, this will called once you get response.
    */
    func doPut(reqUrl:String, requestData:String, completionHandler:( NSURLResponse?, NSData?, NSError?) -> Void){
        
        //Create request from URL
        let url = NSURL(string: reqUrl)
        let cachePolicy = NSURLRequestCachePolicy.ReloadIgnoringLocalCacheData
        let request = NSMutableURLRequest(URL: url!, cachePolicy: cachePolicy, timeoutInterval: 20.0)
        request.HTTPMethod = "PUT"
        
        //Set content type
        let contentType = "application/json"
        NSURLProtocol.setProperty(contentType, forKey: "Content-Type", inRequest: request)
        
        //You can add any header as below
        //request.setValue( "Value", forHTTPHeaderField: "header_key")
        
        // set data
        let requestBodyData = (requestData as NSString).dataUsingEncoding(NSUTF8StringEncoding)
        request.HTTPBody = requestBodyData
        
        // To make Asynchronous Request
        let queue:NSOperationQueue = NSOperationQueue()
        NSURLConnection.sendAsynchronousRequest(request, queue: queue, completionHandler: completionHandler)
        
        print("PUT API called... " )
    }
    /**
    DELETE
    
    :param: reqUrl            URL
    :param: completionHandler CALLBACK
    */
    func doDelete(reqUrl:String, auth:String, completionHandler:( NSURLResponse?, NSData?, NSError?) -> Void){
        
        //Create request from URL
        let url = NSURL(string: reqUrl)
        let cachePolicy = NSURLRequestCachePolicy.ReloadIgnoringLocalCacheData
        let request = NSMutableURLRequest(URL: url!, cachePolicy: cachePolicy, timeoutInterval: 20.0)
        request.HTTPMethod = "DELETE"
        
        //Set content type
        let contentType = "application/json"
        NSURLProtocol.setProperty(contentType, forKey: "Content-Type", inRequest: request)
        
        //You can add any header as below
        //request.setValue( "Value", forHTTPHeaderField: "header_key")
        
        // To make Asynchronous Request
        let queue:NSOperationQueue = NSOperationQueue()
        NSURLConnection.sendAsynchronousRequest(request, queue: queue, completionHandler: completionHandler )
        
        print("Delete API called..." )
    }
}