I'm trying to get my application to send data to the other player that is in the match. I keep getting this error:
Error Domain=Foundation._GenericObjCError Code=0 "(null)".
My code for sending data is below. I've tried sending strings, and custom objects as well and get the same error.
var isReady: Int = 1
let data = NSData(bytes: &isReady, length: sizeof(Int))
do {
try match.sendData(data, toPlayers: match.players, dataMode: .Reliable)
} catch let error as NSError {
print("Error trying to send object: \(error)")
}
Related
I am having an issue in the following swift code, using Parse-Server to save data online.
let xxDico = ["N8": "Eight", "N5": "Five"],
upLoadParseUnit = PFObject(className: "numberClass",
dictionary: xxDico)
print("xxDico : \(xxDico.count)")
upLoadParseUnit.saveInBackground {
(succeeded:Bool, error:Error?) in
if succeeded {
print("\(#function) succeeded!!")
} else {
if error?.localizedDescription == "NAME-USED" {
// A record previously existed with the same name.
print("\(#function) did not succeeded!!\nError: \(error?.localizedDescription)")
return
}
print("Error(1) in \(#function)\n" + (error?.localizedDescription)!)
}
}
And this is what I get in the debugging console:
xxDico : 2
Error(1) in executeUpLoad(_:)
The data couldn’t be read because it isn’t in the correct format.
This seems simple, but what am I doing wrong to get this error?
And what am I supposed to do?
I used this method very much in Swift 1.2: NSURLConnection.sendSynchronousRequest(:_:_:_) but this is apparently deprecated in iOS9. It still works however but now it uses the new Swift 2.0 Error Handling and I don't know how I will get the error message if it fails, ex. if time runs out.
I know I have to put it into a do-catch and then say try before the metho but I dont know how to catch the error message.
do {
let data = try NSURLConnection.sendSynchronousRequest(request, returningResponse: nil)
return data
}
catch _ {
return nil
}
Before I used NSError and then its description property, but now I have no clue.
Use automatic error variable, and you can cast it to NSError if you wish:
catch {
let nsError = error as NSError
print(nsError.localizedDescription)
}
You can now throw any object inheriting ErrorType, and provide custom handling in the catch sentence. You can also cast the error to NSError to access localizedDescription for handling third party errors.
Casting an enum ErrorType will produce a NSError with domain equal to the enum name, code equal to the enum value and an auto-generated localizedDescription with the following format:
The operation couldn’t be completed. (DOMAIN error CODE.)
For example, the following code:
enum AwfulError: ErrorType {
case Bad
case Worse
case Terrible
}
func throwingFunction() throws {
throw AwfulError.Worse
}
do {
try throwingFunction()
}
catch AwfulError.Bad {
print("Bad error")
}
catch let error as NSError {
print(error.localizedDescription)
}
Will print
The operation couldn’t be completed. (AwfulError error 1.)
Despite the question title specifying Swift 2, this answer is for Swift 3.
As #redent84 points out, since Swift 2 an Error object may be a home-made one. Here's a method I wrote to analyze and print the default error object available in a "catch" statement that doesn't specify any specific error type:
// Method to print an unknown Error type object to the system output.
static func printCaughtError(_ unknownError : Error) {
let objectDescription = String(describing: unknownError)
let localizedDescription = unknownError.localizedDescription
if localizedDescription != "" {
if localizedDescription.contains(objectDescription) {
print(localizedDescription)
return
}
if !objectDescription.contains(localizedDescription) {
print(objectDescription + ": " + localizedDescription)
return
}
}
print(objectDescription)
}
Then you can call it like this:
catch {
printCaughtError(error)
}
How to get the error message that is inside userInfo:
let errorMessage = (error as NSError).userInfo["message"] as? String
I used this method very much in Swift 1.2: NSURLConnection.sendSynchronousRequest(:_:_:_) but this is apparently deprecated in iOS9. It still works however but now it uses the new Swift 2.0 Error Handling and I don't know how I will get the error message if it fails, ex. if time runs out.
I know I have to put it into a do-catch and then say try before the metho but I dont know how to catch the error message.
do {
let data = try NSURLConnection.sendSynchronousRequest(request, returningResponse: nil)
return data
}
catch _ {
return nil
}
Before I used NSError and then its description property, but now I have no clue.
Use automatic error variable, and you can cast it to NSError if you wish:
catch {
let nsError = error as NSError
print(nsError.localizedDescription)
}
You can now throw any object inheriting ErrorType, and provide custom handling in the catch sentence. You can also cast the error to NSError to access localizedDescription for handling third party errors.
Casting an enum ErrorType will produce a NSError with domain equal to the enum name, code equal to the enum value and an auto-generated localizedDescription with the following format:
The operation couldn’t be completed. (DOMAIN error CODE.)
For example, the following code:
enum AwfulError: ErrorType {
case Bad
case Worse
case Terrible
}
func throwingFunction() throws {
throw AwfulError.Worse
}
do {
try throwingFunction()
}
catch AwfulError.Bad {
print("Bad error")
}
catch let error as NSError {
print(error.localizedDescription)
}
Will print
The operation couldn’t be completed. (AwfulError error 1.)
Despite the question title specifying Swift 2, this answer is for Swift 3.
As #redent84 points out, since Swift 2 an Error object may be a home-made one. Here's a method I wrote to analyze and print the default error object available in a "catch" statement that doesn't specify any specific error type:
// Method to print an unknown Error type object to the system output.
static func printCaughtError(_ unknownError : Error) {
let objectDescription = String(describing: unknownError)
let localizedDescription = unknownError.localizedDescription
if localizedDescription != "" {
if localizedDescription.contains(objectDescription) {
print(localizedDescription)
return
}
if !objectDescription.contains(localizedDescription) {
print(objectDescription + ": " + localizedDescription)
return
}
}
print(objectDescription)
}
Then you can call it like this:
catch {
printCaughtError(error)
}
How to get the error message that is inside userInfo:
let errorMessage = (error as NSError).userInfo["message"] as? String
I have been trying to modify the following code to manually handle network errors (e.g. disconnection) when retrieving users (_User table) from Parse. As soon as the error returned from the PFQuery is not nil, I should return the completionHandler with the errorMsg, however, the following code doesn't seem to return. Instead the Parse SDK error message keeps printing:
var status: Bool = false
var errorMsg: String? = nil
var query = PFQuery(className: ParseClient.ClassNames.User) //default limit - 100
query.whereKey("email", containsString: "#").findObjectsInBackgroundWithBlock {
(objects: [AnyObject]?, error: NSError?) -> Void in
if error == nil {
status = true
didComplete(success: status, students: objects as! [PFUser], error: nil)
return
} else {
dispatch_async(dispatch_get_main_queue()) {
println("error in fetching all users from Parse")
errorMsg = "There are network problems in fetching user data, please try again later."
didComplete(success: status, students: nil, error: errorMsg)
return
}
}
}
Parse network error message:
2015-09-01 21:28:59.881 UserGame[3564:354410] [Error]: Network connection failed. Making attempt 3 after sleeping for 5.993194 seconds.
Your second return is inside your dispatch_async block, and I think you meant to put it outside.
That said, I'm pretty sure you can't stop Parse from retrying, at least not from within this block. You could also try:
query.cancel()
This "cancels the current network request (if any)."
Hey stackoverflow members,
I work really hard on getting better on Swift, now I have a trivial problem. I'm a former C# developer so Error Handling until now was try {}... catch {}... Message... Done!
Now I'm developing an App which uses some JSON APIs. It's all working, downloading JSON Data, pack them into my Objects but there is one problem. The proper Error Handling..
I have the following code to download & parse JSON:
//Download & Parse JSON
func getJSON(urlToRequest: String) -> NSDictionary {
var url: NSURL = NSURL(string: urlToRequest)
var jsonRequest: NSURLRequest = NSURLRequest(URL: url)
var jsonResponse: AutoreleasingUnsafePointer<NSURLResponse?> = nil
var error: NSError?
var dataValue: NSData = NSURLConnection.sendSynchronousRequest(jsonRequest, returningResponse: jsonResponse, error:&error)
if error.description.isEmpty {
var jsonResult: NSDictionary = NSJSONSerialization.JSONObjectWithData(dataValue, options: NSJSONReadingOptions.MutableContainers, error: &error) as NSDictionary
if error.description.isEmpty {
return jsonResult
}
else {
return NSDictionary(object: "Error: Something with parsing went wrong :(", forKey: "error")
}
}
else {
return NSDictionary(object: "Error: There was an error with your connection :(", forKey: "error")
}
}
The error part is just temporary, the problem is my ViewController just calls one function to get the whole data for the week (days, matchups and so on)
I call it this way:
var rWrapper = RiotWrapper()
let lcsWeek: Week = rWrapper.getWeek("2014-07-07")
My getWeek method calls 3-4 functions which all parse JSON data in relation to the previous responses.
Ok, long story short question: I want to abort all Tasks if JSON or HTTP fails and fill my TableView just with an error message, how can I achieve this?
Something like: if error occurred -> Stop whatever you are doing -> return for example a null erm.. nil for week -> print error
Can someone help me? If someone have some lecture according this topic it will be fine also :D
Thanks in advance!
Btw: sorry for my "bad" english
All of your JSON parsing methods including getWeek should return a tuple with an optional return value and an error. If at any point you get an error in one of your methods from the JSON parsing, just immediately return the error with nil for the return value. Each method up the chain should check for an error from the previous methods and immediately return the error if it finds one:
func getWeek(string : String) -> (Week?, NSError) {
let (result, error) = self.otherMethod()
if error {
return (nil, error)
}
// continue happily ...
}
I would suggest having your function return an optional. It is easy to test and functions can be chained and shortcut.
func getWeek(string : String) -> Week? {
...
if error {
return nil
}
}
This can be quickly evaluated like this:
if let week = getWeek("2014-07-07") {
// handle success case
} else {
// handle nil
}
and check here for how to string together a number of functions that return optional:
https://developer.apple.com/library/prerelease/mac/documentation/Swift/Conceptual/Swift_Programming_Language/OptionalChaining.html