nscoding

i spent all afternoon banging my head against the wall trying to figure out why decoding of this class was failing. the class has a property that is an NSArray of Foo objects. Foo conforms to NSSecureCoding, and i have successfully encoded and decoded that class by itself. i was getting an error in initWithCoder: that said failed to decode class Foo. through some experimentation, i discovered that i needed to add [Foo class] to initWithCoder: in order for it to work. maybe this will help someone else who's having the same problem. my question is, why is this necessary? i found no suggestion

This question already has answers here : Closed 3 years ago . NSObject subclass in Swift: hash vs hashValue, isEqual vs == (2 answers) The FooBar class below has to override the == function of the Equatable type. However, calling contains on an array of FooBar objects does not cause a breakpoint inside the custom == function to get invoked. Is it possible another == function is overriding this custom one? Note: Because FooBar must subclass from NSCoding and NSObject, FooBar does not list Equatable as a protocol because it causes this error: Redundant conformance of 'FooBar' to protocol

I want to add NSCoding support to an c array of structs. Specifically this is for a subclass of MKPolyline , i.e. this is what I have to work with: @property (nonatomic, readonly) MKMapPoint *points; @property (nonatomic, readonly) NSUInteger pointCount; + (MKPolyline *)polylineWithPoints:(MKMapPoint *)points count:(NSUInteger)count; I found a good answer on how to encode a individual struct . E.g. NSValue* point = [NSValue value:&aPoint withObjCType:@encode(MKMapPoint)]; [aCoder encodeObject:point forKey:@"point"]; .... NSValue* point = [aDecoder decodeObjectForKey:@"point"];

My Problem: saveInBackground isn't working. The Reason It's not working: I'm saving PFObjects stored in an NSArray to file using NSKeyedArchiving . The way I do that is by implementing NSCoding via this library . For some reason unknown to me, several other fields are being added and are set to NULL. I have a feeling that this is screwing up the API call to saveInBackground . When I call saveInBackground on the first set of objects (before NSKeyedArchiving ) saveInBackground works just fine. However, when I call it on the second object (after NSKeyedArchiving ) it does not save. Why is this?

I'm learning about the NSSecureCoding protocol introduced by Apple in iOS 6. From my understanding so far, it should be used whenever a class encodes/decodes instances of itself, in order to prevent substitution attacks. I'm wondering whether it would be appropriate to use it in other cases. Specifically if a class conforms to NSCoding by encoding/decoding its instance variables, as opposed to the whole instance of itself, would it still be advisable to implement NSSecureCoding ? EDIT Suppose I have a class that is implementing NSCoding like follows - (void)encodeWithCoder:(NSCoder *)encoder {

For a data recovery program I need to be able to extract the values+types from files written by NSArchiver, without having access to Apple's CF / NS frameworks. The OS X file command reports such files as: NeXT/Apple typedstream data, little endian, version 4, system 1000 Is there any documentation on how these files are encoded, or has anyone come up with code that can parse them? Here's an example of such data (also: downloadable ): 04 0B 73 74 72 65 61 6D 74 79 70 65 64 81 E8 03 ..streamtyped... 84 01 40 84 84 84 12 4E 53 41 74 74 72 69 62 75 ..@....NSAttribu 74 65 64 53 74 72 69 6E 67 00

Here's a NSCoding compliant object. I would like to save and recover it from the app's documents directory in Swift 3. I imagine it's a save method and recover method. How is this done? import Foundation class Book: NSObject, NSCoding { var title: String var author: String var pageCount: Int var categories: [String] var available: Bool init(title:String, author: String, pageCount:Int, categories:[String],available:Bool) { self.title = title self.author = author self.pageCount = pageCount self.categories = categories self.available = available } // MARK: NSCoding required convenience init?