For whatever reason my application crashes everytime it decodes my Bool value. It didn't crash before I updated to Swift 3. I have no idea what I'm doing wrong. If I take out the Bool value my application runs fine without crashing.
This has been changed for Swift 3. There are associated decode...() functions for various different types.
The correct syntax is now:
let myBool = aDecoder.decodeBool(forKey: PropertyKey.completedKey)
Related
I have recently released a new version of our app and during beta testing, it's crashing on all iOS 10 devices but not other versions. Since we have Crashlytics, we found a strange crash message in the backend that we can confirm is the reason all iOS 10 crashing since it's 100% iOS 10 and there's like 40 of them.
It reads as follows:
Fatal Exception: RLMException
Property Article.id is declared as String, which is not a supported managed Object property type. If it is not supposed to be a managed property, either add it to ignoredProperties() or do not declare it as #objc dynamic. See https://realm.io/docs/swift/latest/api/Classes/Object.html for more information.
And here's the object:
class Article: Object {
#objc dynamic var id: String = UUID().uuidString
// others...
override static func primaryKey() -> String? {
return "id"
}
}
As you can see, this is perfectly nomral and runs fine on other iOS. In Realm's doc, it LITERALLY SAYS to use String with #objc dynamic and there's no way it's unsupported. I suspect there's nothing special about Article.id, and since Article starts with A, it happens to be the first String property of all realm Objects. Maybe somehow all Strings stopped working on iOS 10?
Can anyone offer some advice or insights?(Please don't say things like drop iOS 10 support. For now, we need it.)
We ran into the same issue a couple of times, trying to drag Realm fully into Swift. This is not really the answer but more of a workaround we've had success with when needing backward compatibility.
It's an ObjC object, not Swift.
There's something going on with the bridging, perhaps conforming to NSCopy'ing or something along those line, so just change it to read
#objc dynamic var id = NSUUID().uuidString
See the Getting Started Guide in the Models section which calls for using NSUUID
NSUUID: An object representing a universally unique value that bridges
to UUID; use NSUUID when you need reference semantics or other
Foundation-specific behavior.
Turns out it was a Realm's bug. We happen to have another app that runs just fine on iOS 10, and after some inspection we realized that it was using Realm 4.3.2, instead of 4.4.1. After we downgraded Realm to 4.3.2, this problem disappeared.
I've looked at the other questions on here about subscripting with dictionaries and I didn't see anything that quite fit what my scenario is. It may be that I'm still too new to Swift to realize it but in any case here is my scenario. I'm getting the typical can't "Subscript" dictionary with type string. I've seen the posts on here about it being an optional and needing to unwrap it however when I try that, Xcode suggests that I remove the !, so I do that, then I get the subscript error.
I've watched tons of tutorials on swift development and a lot of them use playgrounds and I never remembered seeing anyone have to do this in any of the tutorials. So I tried the same thing in a playground and it worked.
Here is what I have in the ViewController that DOESN'T work.
var validFields:Dictionary = ["loanBalanceInput":false,"cashOutInput":false,"appraisedValueInput":false,"interestRateInput":false]
func validationSuccess(sender:UITextField){
sender.backgroundColor = green
switch sender {
case loanBalanceInput:
validFields["loanBalanceInput"] = true
break
default:
break
}
}
What I've done is create a dictionary of strings that refer to textfields and their validation status to track whether or not they have been validated. The concept is that when everything in the dictionary is true, I can activate the calculate button.
However I get the "cannot subscript a value of type dictionary with an index of type string" error... However this code in a playground works...
var validatedFields:Dictionary = ["loanBalanceInput":false,"cashOutInput":false,"appraisedValueInput":false,"interestRateInput":false]
validatedFields["loanBalanceInput"]
validatedFields["loanBalanceInput"] = true
I don't understand what's going on here. Is it because this is an optional?
#IBOutlet weak var loanBalanceInput: UITextField!
I'm not unwrapping it in my switch? I'm not trying to get at the value of loanBalanceInput though, I'm just checking to see if it was the sender.
Normally a Swift Dictionary declaration needs also the type of the containing keys and values like
var validFields: Dictionary<String,Bool> = [" ...
but as the compiler can infer the type just delete the annotation.
I'm using a dictionary to evaluate an expression, when the expression has variables and the dictionary is actually used by NSExpression, something happens and I get EXC_BAD_ACCESS when trying to update the dictionary, this only happens when debugging in an iPhone6, not in the simulator and not in an iPhone 4S.
let strExpression = "a+b+20"
let exp = NSExpression(format:strExpression)
self.dictionary = ["a":10.0, "b":15.0, "c":25.0]
let value:AnyObject = exp.expressionValueWithObject(self.dictionary, context: nil)
let doubleValue = value as Double
self.dictionary.updateValue(doubleValue, forKey: "c")
Something really weird is that if i add this line just after creating the dictionary, then it woks fine:
let newDic = self.dictionary
I,m using iOS 8.1. Thanks in advance!
With #bensarz comment, I thought it might be helpful for others searching for answers if I put the response into an actual answer instead of a comment.
Per #LeeWhitney's response on a similar post:
Looks like a compiler bug.
Have you tried switching between Release and Debug then rebuilding? If debug works but not release it can be an indication of a compiler/optimizer bug.
Does it happen in the simulator also?
Your code works for me on iOS 8.1 with XCode 6.1.
Solution:
The issue seems to be solved by changing the 'Optimization Level' under the 'Swift Compiler - Code Generation' to 'None'. The issue seems to be with the 'Fastest' Compiler optimization level.
Also, a work around that I've found original before the compiler change:
If you use a let statement prior to assigning values in the dictionary, it seems to alleviate the issue. More information found at link below:
EXC_BAD_ACCESS on iOS 8.1 with Dictionary
Apple has the following method in the SKPhysicsBody class.
/* Returns an array of all SKPhysicsBodies currently in contact with this one */
func allContactedBodies() -> [AnyObject]!
I noticed it returns an array of AnyObject. So I read about how to deal with down casting AnyObject Here
I want to loop through the allContactedBodies array of my physics body. The problem is, no matter what I try I just can't get things to work.
I tried this first:
for body in self.physicsBody.allContactedBodies() as [SKPhysicsBody] {
}
But I get this error.
fatal error: array cannot be downcast to array of derived
I also tried this:
for object in self.physicsBody.allContactedBodies() {
let body = object as SKPhysicsBody
}
But this also crashes with the following:
And similarly I tried this:
for object in self.physicsBody.allContactedBodies() {
let body = object as? SKPhysicsBody
}
There is no crash, but "body" becomes nil.
And if I don't cast at all, I don't get a crash. For example:
for object in self.physicsBody.allContactedBodies() {
}
But obviously I need to cast if I want to use the actual type.
So then as a test I just tried this:
let object: AnyObject = SKPhysicsBody()
let body = object as SKPhysicsBody
And this also results in the same crash that is in the picture.
But other types won't crash. For example, this won't crash.
let object: AnyObject = SKNode()
let node = object as SKNode
So my question is, how can I correctly loop through the allContactedBodies array?
Edit: I am running Xcode 6 beta 4 on iOS 8 beta 4 device.
Edit 2: More Information
Ok so I just did some more testing. I tried this:
let bodies = self.physicsBody.allContactedBodies() as? [SKPhysicsBody]
If "allContactedBodies" is empty, then the cast is successful. But if "allContactedBodies" contains objects, then the cast fails and "bodies" will become nil, so I can't loop through it. It seems that currently it is just NOT POSSIBLE to cast AnyObject to SKPhysicsBody, making it impossible to loop through the "allContactedBodies" array, unless someone can provide a workaround.
Edit 3: Bug still in Xcode 6 beta 5. Workaround posted below still works
Edit 4: Bug still in Xcode 6 beta 6. Workaround posted below still works
Edit 5: Disappointed. Bug still in Xcode 6 GM. Workaround posted below still works
EDIT 6: I have received the following message from Apple:
Engineering has provided the following information:
We believe this issue has been addressed in the latest Xcode 6.1 beta.
BUT IT IS NOT, the bug is still in Xcode 6.1.1!!! Workaround still works.
Edit 7: Xcode 6.3, still not fixed, workaround still works.
After much trial and error, I have found a workaround to my problem. It turns out that you don't need to downcast at all to access the properties of the SKPhysicsBody, when the type is AnyObject.
for object in self.physicsBody.allContactedBodies() {
if object.node??.name == "surface" {
isOnSurface = true
}
}
Update: This was a bug, and it's fixed in iOS 9 / OS X 10.11. Code like the following should just work now:
for body in self.physicsBody.allContactedBodies() {
// inferred type body: SKPhysicsBody
print(body.node) // call an API defined on SKPhysicsBody
}
Leaving original answer text for posterity / folks using older SDKs / etc.
I noticed this in the related questions sidebar while answering this one, and it turns out to be the same underlying issue. So, while Epic Byte has a workable workaround, here's the root of the problem, why the workaround works, and some more workarounds...
It's not that you can't cast AnyObject to SKPhysicsBody in general — it's that the thing(s) hiding behind these particular AnyObject references can't be cast to SKPhysicsBody.
The array returned by allContactedBodies() actually contains PKPhysicsBody objects, not SKPhysicsBody objects. PKPhysicsBody isn't public API — presumably, it's supposed to be an implementation detail that you don't see. In ObjC, it's totally cool to cast a PKPhysicsBody * to SKPhysicsBody *... it'll "just work" as long as you call only methods that the two classes happen to share. But in Swift, you can cast with as/as?/as! only up or down the type hierarchy, and PKPhysicsBody and SKPhysicsBody are not a parent class and subclass.
You get an error casting let obj: AnyObject = SKPhysicsBody(); obj as SKPhysicsBody because even the SKPhysicsBody initializer is returning a PKPhysicsBody. Most of the time you don't need to go through this dance (and have it fail), because you get a single SKPhysicsBody back from an initializer or method that claims to return an SKPhysicsBody — all the hand-wavy casting between SKPhysicsBody and PKPhysicsBody is happening on the ObjC side, and Swift trusts the imported ObjC API (and calls back to the original API through the ObjC runtime, so it works just as it would in ObjC despite the type mismatch).
But when you cast an entire array, a runtime typecast needs to happen on the Swift side, so Swift's stricter type-checking rules come into play... casting a PKPhysicsBody instance to SKPhysicsBody fails those rules, so you crash. You can cast an empty array to [SKPhysicsBody] without error because there aren't any objects of conflicting type in the array (there aren't any objects in the array).
Epic Byte's workaround works because Swift's AnyObject works like ObjC's id type: the compiler lets you call methods of any class on it, and you just hope that at runtime you're dealing with an object that actually implements those methods.
You can get back a little bit of compile-time type safety by explicitly forcing a side cast:
for object in self.physicsBody.allContactedBodies() {
let body = unsafeBitCast(object, SKPhysicsBody.self)
}
After this, body is an SKPhysicsBody, so the compiler will let you call only SKPhysicsBody methods on it... this behaves like ObjC casting, so you're still left hoping that the methods you call are actually implemented by the object you're talking to. But at least the compiler can help keep you honest. (You can't unsafeBitCast an array type, so you have to do it to the element, inside the loop.)
This should probably be considered a bug, so please let Apple know if it's affecting you.
I'm trying to use CoreBluetooth's retrievePeripheral :
- (void)retrievePeripherals:(NSArray *)peripheralUUIDs;
The documentation says peripheralUUIDs should be a NSArray of CFUUIDRef. In the Apple sample project temperatureSensor, it is called as :
[centralManager retrievePeripherals:[NSArray arrayWithObject:(id)uuid]];
(uuid being a CFUUIDRef)
When I use the exact same code in XCode 4.5.1, IOS6, I'm getting a error :
Cast of C pointer type 'CFUUIDRef' (aka 'const struct __CFUUID *') to Objective-C pointer type 'id' requires a bridged cast
I would say (though I'm far from sure) that the reason it works in TemperatureSensor and not in my project is because TemperatureSensor seems not to use ARC whereas my project does.
Xcode suggests 2 ways of solving the problem : adding a __bridge or using CFBridgingRelease(). I tried them both and I'm under the impression that the function does not work [Edit] because the delegate methode didRetrievePeripheral: never gets called [/Edit] (my understanding is that these operation would change the C-style structs into objective-C-objects thus creating a NSUUID, and the method can't use it, but, again I'm really not sure)
So what should I do ? I've been searching on google for examples of retrievePeripherals using ARC, but without success.
In the temperature sensor change this line and run
LeDiscovery.m
-(void) startScanningForUUIDString:(NSString *)uuidString
{
[centralManager scanForPeripheralsWithServices:nil options:0];
}
change the word nil and assume 0.
If you want more check this link.
I hope its useful for you.
Turns out the problem was much simpler than that. I copied/pasted some code from TemperatureSensor, specifically the DidRetrievePeripheral. But it turns out, there's an error in this code (it's DidRetrievePeripheralS), so the delegate method never gets called. I think the bug is already reported.
Thanks/sorry