I'm trying to read the Linkedin response in swift.
My object is something like this ["positions":["values":["data1","data2","data3"]]]
if let positions: NSDictionary = info["positions"] as NSDictionary!{
if let positionsInfo: [NSDictionary] = positions["values"] as? [NSDictionary]{
for position : NSDictionary! in positionsInfo {
dosomething(position, person:usr)
}
}
}
If I do a StepOver line by line it works correctly. But if I run it i'll get a EXC_BAD_ADDRESS(code=1,address=0x7966b04) I enabled Zombie objects and ran it on Instruments. I'm pretty sure this is the code which is causing the problem. But not sure what is wrong with it.
The moment you used ! you opened yourself up for crashes if there were any problem. You must use as? to make sure that the data is actually what you think it is.
There are many blog posts out there on how to safely parse JSON into Swift data structures. It's now almost a rite of passage for Swift bloggers.
http://robots.thoughtbot.com/efficient-json-in-swift-with-functional-concepts-and-generics
http://chris.eidhof.nl/posts/json-parsing-in-swift.html
https://github.com/owensd/json-swift
https://github.com/lingoer/SwiftyJSON
Of course the many packages: https://github.com/search?q=%5Bswift%5D+json
http://robnapier.net/functional-wish-fulfillment - My own version on top of all the others
Related
So my code was working perfectly fine but today it is returning nil when I try to cast Firebase's snapshot.value to a Bool. I haven't made any change to code at all. But it works fine if I cast it to a String (as? String returns "true").
Same issue at another place where I was casting to [String: Bool].
One thing that is different from earlier, I installed Xcode 10 beta 3 today (Xcode 9.4 is installed too). Both Xcode versions are returning nil. Here's the code:
if let currentUserId = Auth.auth().currentUser?.uid{
Database.database().reference().child("users/\(currentUserId)/share").observe(.childAdded) { (snapshot) in
let data = snapshot.value as? Bool
if data == true{
self.showNotificationsBadge()
}
}
}
Edit: Snapshot is not nil. You can see that in the console pane. I have printed both snapshot.key and .value.
Edit 2: I'm sorry if my question caused any confusions. The main purpose of this question is to know the problem, is it Firebase SDK or Xcode. Because it was working perfectly till now. I know how I can tackle this and how can I convert a String to a Bool.
Edit 3: Thank you everyone for your answers. I'm sorry I was unable to deliver my thoughts correctly. I just want to know about this unpredicted behavior and why is it happening? Who is the culprit here? Xcode, Firebase SDK? This code worked PERFECTLY FINE for about a month. I'm not asking for a solution, I'm just curious about this behavior. It would be great if someone from team Firebase can explain this issue.
Edit 4: Removed image and added code. Also figured out the issue thanks to #Jay's comment.
You need check if the snapshot is nil before checking the value.
if let data = snapshot.value as? Bool {
....
}
This happened to me just recently. I discovered that I had quotes around the child value, eg. "true". Remove the quotes and the solution from #Maximo should work as expected.
I try to create a function for querying the Facebook database. Unfortunately, the syntax changed with the last version of swift. Maybe someone can post me the solution ?
Thx.
Func donneesFB
It's a lot easier to help you if you post your code as text instead of in an image.
Two things that will likely help you out here:
First, cast your result to the type of dictionary you are expecting before trying to access it:
guard let resultDict = result as? [String:Any] else { return }
You should now be able to use it like you tried to:
let nom = resultDict["name"] as? String
Secondly, for the error on your first line, simply get rid of the argument labels, nom, prenom and so on, leaving just the types.
I got this error on Crashlytics this morning and I can't firgure out what the problem is. It would be awesome to get your opinions about it. I thInk it's most likely a multi threading issue. But I'm not able to pin point exactly what it is.
EDIT: I dug a little deeper and here's the code that's failing:
Also, I've figured out that the error is:
Could not cast value of type '__NSSingleObjectArrayI' (0x1aa60bca0) to 'NSMutableArray' (0x1aa60bd90).
2016-09-22 08:29:34.136764 GrabbnGo[4204:822290] Could not cast value of type '__NSSingleObjectArrayI' (0x1aa60bca0) to 'NSMutableArray' (0x1aa60bd90).
This was working perfectly all this while and it's suddenly causing problems and the app is already on the store :/
json = try NSJSONSerialization.JSONObjectWithData(data!, options: NSJSONReadingOptions()) as? [String: AnyObject]
let str = NSString(data: data!, encoding: NSUTF8StringEncoding)
print(str)
let OrderDictionary = json as NSDictionary
let result = OrderDictionary.objectForKey("result") as! NSMutableArray
OK, this sort of has a unique answer. Basically, you're misusing NSJSONSerialization, and it's a time-bomb bug that eventually bit you.
According to the documentation:
https://developer.apple.com/reference/foundation/jsonserialization
All objects are instances of NSString, NSNumber, NSArray, NSDictionary, or NSNull.
This is a very simple and clear sentence. You should respect it. It says nothing about NSMutableArray, only NSArray. The JSON parser is using whatever compatible (subclass) object for the NSArray that it so chooses. If there's only one item in the array, it appears that the internal type __NSSingleObjectArray is a lot more efficient, probably both in speed and memory.
There is almost certainly a change on the server (or customer behavior) such that result now (often? sometimes? always?) has only 1 item in it, so the JSON parser made a different choice that you're not supposed to care about.
All you need to do is change it to NSArray and construct an NSMutableArray from it if you really need:
let myJSONParsedArray: NSArray = ...
let myMutableArray = NSMutableArray(myJSONParsedArray)
But first learn about why force unwrapping is so dangerous, especially in a network code environment, when you can't trust any data at all, regarding type and value and maliciousness, ever!!
I was trying to pass my swift object from the iOS app to the Watch. However, I found it works for basic types like NSString, but my custom object type.
My custom object is able to cast to NSData
I've made my object implement NSObject and NSCoding, which works well. I can do following without problem:
let encodedChordProgression = NSKeyedArchiver.archivedDataWithRootObject(chordProgressions[1])
let decodedChordProgression = NSKeyedUnarchiver.unarchiveObjectWithData(encodedChordProgression) as! ChordProgression
NSLog("get decodedChordProgression = \(decodedChordProgression.description)")
WatchConnectivity code works for NSString
In iPhone:
try WatchSessionManager.sharedManager.updateApplicationContext(["data": "mystringishere"])
with Watch:
dispatch_async(dispatch_get_main_queue()) { [weak self] in
self?.dataSourceChangedDelegates.forEach { $0.dataSourceDidUpdate(applicationContext["data"] as! NSString)}
}
works.
My custom object with WatchConnectivity Failed
However, when I switch the object to my own object, it failed by not calling the dataSourceChangedDelegates callback function. That is:
In iPhone:
let encodedChordProgression = NSKeyedArchiver.archivedDataWithRootObject(chordProgressions[1])
try WatchSessionManager.sharedManager.updateApplicationContext(["data": encodedChordProgression])
with Watch:
dispatch_async(dispatch_get_main_queue()) { [weak self] in
self?.dataSourceChangedDelegates.forEach { $0.dataSourceDidUpdate(applicationContext["data"] as! NSData)}
}
and
func dataSourceDidUpdate(encodedChordProgression: NSData) {
let chordProgression = NSKeyedUnarchiver.unarchiveObjectWithData(encodedChordProgression) as! ChordProgression
NSLog("get something here: \(chordProgression.description)")
}
What I've tried & my problem
I've tried to read the system.log of both the iPhone app and Watch app, but I couldn't find any clue, which is the biggest problem I have now.
The full code is: here (checkout 7f2a72c6004f6580e2a38a2d7fd0ed2cef8a2b2e)
NSKeyedArchiver/NSKeyedUnarchiver won't work in this way unfortunately. This is because even though you may share class files between your watchkit and iOS targets, they are essentially different classes to the compiler because they are compiled for different architectures.
What I have done to get around this issue myself (because I initially tried to do the same thing) is serialize my custom objects to a json dictionary (or json NSData if you like) and send that. Here is a github project I have made that automatically serializes your swift objects to json for you (specifically with this use case in mind).
I tried with "NSKeyedArchiver/NSKeyedUnarchiver" and this is working perfectly.
no need to go for serialization and all.
your dictionary should have same type of data and Archiver is doing it very well.
I have created an iOS app using Swift and everything is working fine and dandy on the simulator. I get no errors or crashes at all, but when I submit my app to put up on the app store Apple rejects it and lets me know that it crashes when the user makes a selection. I cannot recreate this error/crash. I took the crash logs and symbolicated them. This line of code came up as the culprit for the crashes:
linksToPass = getLinks(season) as [String:[String]]
This line is trying to store the resulting Dictionary from the getLinks() function I created. It for sure is getting a dictionary and if there is no dictionary to send back I create a dictionary which has error information in it, so it is for sure returning a dictionary in that format no matter what. Seeing as I cannot recreate the crash, I am just trying to error check this line of code in any way possible so it does't crash when I resubmit to Apple.
I tried checking if the resulting dictionary was nil like so:
if(getLinks(seasons) != nil){
linksToPass = getLinks(season) as [String:[String]]
}
This is not valid though, and XCode lets me know that UInt8 is not compatible with NSDictionary or something of that nature.
I then fixed that line and changed it to this:
if(getLinks(seasons) != ["":[""]]){
linksToPass = getLinks(season) as [String:[String]]
}
I am just not sure if this is even a good way to check for errors. I was wondering if there were any suggestions on how I may go about making sure this line does not fail and result in a crash. Thank you very much.
EDIT:
Here is my getLinks() function if that helps add more info to the problem:
var season = ""
let hymn_links = Hymn_Links()
func getLinks (nameofseason:String) -> NSDictionary
{
switch (nameofseason)
{
default:
return ["Maps Not Found": []]
}
}
EDIT #2:
This is my updated getLinks() function with the use of optionals.
func getLinks (nameofseason:String) -> NSDictionary?
{
switch (nameofseason)
{
default:
return nil
}
}
Also in my statement of linksToPass I changed it to:
if let links = getLinks(season) as? [String:[String]]
{
linksToPass = links
hymnnames = [String] (linksToPass.keys)
}
There are some known issues with the Swift optimiser. Some people have resorted to shipping with debug builds.
My suggestion would be to test with an optimised build to see if you can reproduce it. You can then try shipping a debug build to the App store.
General Code Comments
Why are you returning an NSDictionary rather than a Swift dictionary anyway? Without knowing the contents and creation method for your hymn_links object I can't be sure how good it is.
I would avoid as casts until Swift 1.2 and stick to using as? and then handling the nil case. At least in your "Edit 2" a nil will cause a crash as nil cannot be cast to [String:[String]] although [String:[String]]? should be possible.
Can you guarantee that all of the items returned by the switch statement will never under any circumstances be nil? If not getLinks should return an Optional.
Note that is is virtually impossible for getLinks to know that one of the items will never be nil and in Swift un-handed nils are a crash waiting to happen. Unless all these methods correctly handle nil.
Return an Optional and handle that in the statement that calls getLinks.
Languages handle nils differently, Objective-C handles them rather well, Java and Swift by crashing. But Swift has a mechanism to handle nils without crashing: Optionals, use it.