NSURLSession send parameters with get - json

Question

I'm trying to parse information from a php, but i need to send a dictionary parameter so i try things ... i saw tutorials,examples but i'm stuck so i went back to the start: (What it's the good way for do this?)
func asd(){
let urlPath = "http://xxxxx.php"
let url: NSURL = NSURL(string: urlPath)
let request = NSMutableURLRequest(URL: url)
request.HTTPMethod = "GET"
var parm = ["id_xxxx": "900"] as Dictionary
//I THINK MY PROBLEM IT'S HERE! i dont know how to link parm with session, i try is with session.uploadTaskWithRequest(<#request: NSURLRequest?#>, fromData: <#NSData?#>) but doesn't work
let session = NSURLSession.sharedSession()
let task = session.dataTaskWithURL(url, completionHandler: {data, response, error -> Void in
println("Task completed")
if(error) {
// If there is an error in the web request, print it to the console
println(error.localizedDescription)
}
var err: NSError?
var jsonResult = NSJSONSerialization.JSONObjectWithData(data, options: NSJSONReadingOptions.MutableContainers, error: &err) as NSDictionary
if(err?) {
// If there is an error parsing JSON, print it to the console
println("JSON Error \(err!.localizedDescription)")
}
println(jsonResult.debugDescription)
let results: NSArray = jsonResult["x"] as NSArray
dispatch_async(dispatch_get_main_queue(), {
self.tableData = results
self.OfertaGridViewLista!.reloadData()
})
})
task.resume()
}
Thanks!

Answer 1

GET data needs to be part of the url's query string. Some methods will accept a dictionary of parameters for POST/PUT requests, but these methods will not add the dictionary to the url for you if you're using the GET method.
If you'd like to keep your GET parameters in a Dictionary for cleanliness or consistency, consider adding a method like the following to your project:
func buildQueryString(fromDictionary parameters: [String:String]) -> String {
var urlVars:[String] = []
for (k, value) in parameters {
let value = value as NSString
if let encodedValue = value.addingPercentEncoding(withAllowedCharacters: NSCharacterSet.urlQueryAllowed) {
urlVars.append(k + "=" + encodedValue)
}
}
return urlVars.isEmpty ? "" : "?" + urlVars.joined(separator: "&")
}
This method will take a dictionary of key/value pairs and return a string you can append to your url.
For example, if your API requests allow for multiple request methods (GET/POST/etc.) you'll only want to append this query string to your base api url for GET requests:
if (request.HTTPMethod == "GET") {
urlPath += buildQueryString(fromDictionary: parm)
}
If you're only making GET requests, there's no need to check for which method you'll be using to send your data.

Answer 2

Bit crazy that none of the answers here suggest using NSURLComponents and NSURLQueryItem objects. That is the safest and most modern way to do this.
var iTunesSearchURL = URLComponents(string: "https://itunes.apple.com/search")!
iTunesSearchURL.queryItems = [URLQueryItem(name: "term", value: trackName),
URLQueryItem(name: "entity", value: "song"),
URLQueryItem(name: "limit", value: "1")]
let finalURL = iTunesSearchURL.url

Answer 3

#paul-mengelt's answer in Objective C:
-(NSString *) buildQueryStringFromDictionary:(NSDictionary *)parameters {
NSString *urlVars = nil;
for (NSString *key in parameters) {
NSString *value = parameters[key];
value = [value stringByAddingPercentEncodingWithAllowedCharacters:[NSCharacterSet URLHostAllowedCharacterSet]];
urlVars = [NSString stringWithFormat:#"%#%#=%#", urlVars ? #"&": #"", key, value];
}
return [NSString stringWithFormat:#"%#%#", urlVars ? #"?" : #"", urlVars ? urlVars : #""];
}

Answer 4

Adapted for Swift 3
static func buildQueryString(fromDictionary parameters: [String:String]) -> String {
var urlVars:[String] = []
for (k,value) in parameters {
if let encodedValue = value.addingPercentEncoding(withAllowedCharacters: CharacterSet.urlQueryAllowed) {
urlVars.append(k + "=" + encodedValue)
}
}
return urlVars.isEmpty ? "" : "?" + urlVars.joined(separator: "&")
}

Answer 5

fixed objective C function
+(NSString *)buildQueryStringFromDictionary:(NSDictionary *)parameters
{
NSString *urlVars = #"";
for (NSString *key in parameters)
{
NSString *value = parameters[key];
value = [value stringByAddingPercentEncodingWithAllowedCharacters:[NSCharacterSet URLHostAllowedCharacterSet]];
urlVars = [NSString stringWithFormat:#"%#%#%#=%#", urlVars, urlVars.length ? #"&": #"", key, value];
}
return [NSString stringWithFormat:#"%#%#", urlVars ? #"?" : #"", urlVars ? urlVars : #""];
}

Answer 6

NSURL *url = [NSURL URLWithString:[NSString stringWithFormat:#"url_to_your_web_service.php/?key=%#",value]];
NSURLSessionConfiguration *defaultConfigObject = [NSURLSessionConfiguration defaultSessionConfiguration];
NSURLSession *defaultSession = [NSURLSession sessionWithConfiguration: defaultConfigObject];
NSURLSessionDataTask * dataTask = [defaultSession dataTaskWithURL:url
completionHandler:^(NSData *data, NSURLResponse *response, NSError *error) {
if(error == nil){
NSString * text = [[NSString alloc] initWithData: data encoding: NSUTF8StringEncoding];
NSLog(#"Data = %#",text);
}
}
}
];
[dataTask resume];
retrieve key's value inside your php:
$value=$_GET['key'];