Swiftで、NSObjectのサブクラスを定義するスコープとdynamicの有無によるKVC/KVO挙動の違い

gistfile1.md

NSObjectのサブクラスを定義するスコープとdynamicの有無によるKVC/KVO挙動の違い

• ファイルスコープ
  • dynamicなし、KVC使える、KVO使えない。
  • dynamicあり、KVC/KVO使える。
• funcスコープ
  • dynamicなし、KVC/KVO使えない。
  • dynamicあり、KVC/KVO使える。

ファイルスコープはNSObjectではなく、そのサブクラスをサブクラス化してるような挙動。

SwiftでKVC/KVOを利用した場合の挙動。 Objective-CからSwiftのクラスを利用する場合は、ファイルスコープしか使えずdynamicの有無に直接的な影響は受けない。

gistfile2.swift

import Foundation
import XCTest

class testTests: XCTestCase {
    
    func testKVCandKVO_ClassInsideFuncNonDynamicProperty() {
        
        println("\n==== \(__FUNCTION__)")
        
        @objc(ClassInsideFuncNonDynamicProperty) class ClassInsideFunc: NSObject {
            var nonDynamicProperty = 0
            dynamic var dynamicProperty = 0
            override func valueForUndefinedKey(key: String) -> AnyObject? {
                println("\(key) is undefined on \(self)")
                return nil
            }
        }
        
        let propertyName = "nonDynamicProperty"
        
        var e = ClassInsideFunc()
        e.addObserver(self, forKeyPath: propertyName, options: .Initial | .New, context: nil)
        e.nonDynamicProperty = 2
        e.removeObserver(self, forKeyPath: propertyName)
        
        
        var value = e.valueForKey(propertyName)
        println("before setValue: \(value)")
        e.setValue(0, forKey: propertyName)   // NSUnknownKeyException
        value = e.valueForKey(propertyName)
        println("after setValue: \(value)")
    }
    
    func testKVCandKVO_ClassInsideFuncDynamicProperty() {
        
        println("\n==== \(__FUNCTION__)")

        class ClassInsideFunc: NSObject {
            dynamic var dynamicProperty = 0
            override func valueForUndefinedKey(key: String) -> AnyObject? {
                println("\(key) is undefined on \(self)")
                return nil
            }
        }
        
        let propertyName = "dynamicProperty"
        
        var e = ClassInsideFunc()
        e.addObserver(self, forKeyPath: propertyName, options: .Initial | .New, context: nil)
        e.dynamicProperty = 2
        e.removeObserver(self, forKeyPath: propertyName)
        
        
        var value = e.valueForKey(propertyName)
        println("before setValue: \(value)")
        e.setValue(0, forKey: propertyName)
        value = e.valueForKey(propertyName)
        println("after setValue: \(value)")
    }
    
    func testKVCandKVO_ClassOutsideFuncNonDynamicProperty() {
        
        println("\n==== \(__FUNCTION__)")

        let propertyName = "nonDynamicProperty"
        
        var e = ClassOutsideFunc()
        e.addObserver(self, forKeyPath: propertyName, options: .Initial | .New, context: nil)
        e.nonDynamicProperty = 2
        e.removeObserver(self, forKeyPath: propertyName)
        
        var value = e.valueForKey(propertyName)
        println("before setValue: \(value)")
        e.setValue(0, forKey: propertyName)
        value = e.valueForKey(propertyName)
        println("after setValue: \(value)")
    }
    
    func testKVCandKVO_ClassOutsideFuncDynamicProperty() {
        
        println("\n==== \(__FUNCTION__)")

        let propertyName = "dynamicProperty"

        var e = ClassOutsideFunc()
        e.addObserver(self, forKeyPath: propertyName, options: .Initial | .New, context: nil)
        e.dynamicProperty = 2
        e.removeObserver(self, forKeyPath: propertyName)
        
        var value = e.valueForKey(propertyName)
        println("before setValue: \(value)")
        e.setValue(0, forKey: propertyName)
        value = e.valueForKey(propertyName)
        println("after setValue: \(value)")
    }
    
    override func observeValueForKeyPath(keyPath: String, ofObject object: AnyObject, change: [NSObject : AnyObject], context: UnsafeMutablePointer<Void>) {
        println("\(keyPath) = \(change)")
    }
    
}

@objc class ClassOutsideFunc: NSObject {
    var nonDynamicProperty = 0
    dynamic var dynamicProperty = 0
    
    override func valueForUndefinedKey(key: String) -> AnyObject? {
        println("\(key) is undefined on \(self)")
        return nil
    }
}

gistfile3.txt

Test Suite 'All tests' started at 2015-04-07 07:14:16 +0000
Test Suite 'testTests.xctest' started at 2015-04-07 07:14:16 +0000
Test Suite 'testTests' started at 2015-04-07 07:14:16 +0000
Test Case '-[testTests.testTests testKVCandKVO_ClassInsideFuncDynamicProperty]' started.

==== testKVCandKVO_ClassInsideFuncDynamicProperty()
dynamicProperty = [kind: 1, new: 0]
dynamicProperty = [kind: 1, new: 2]
before setValue: Optional(2)
after setValue: Optional(0)
Test Case '-[testTests.testTests testKVCandKVO_ClassInsideFuncDynamicProperty]' passed (0.001 seconds).
Test Case '-[testTests.testTests testKVCandKVO_ClassInsideFuncNonDynamicProperty]' started.

==== testKVCandKVO_ClassInsideFuncNonDynamicProperty()
nonDynamicProperty is undefined on <ClassInsideFuncNonDynamicProperty: 0x10041d260>
nonDynamicProperty = [kind: 1, new: <null>]
nonDynamicProperty is undefined on <ClassInsideFuncNonDynamicProperty: 0x10041d260>
before setValue: nil
<unknown>:0: error: -[testTests.testTests testKVCandKVO_ClassInsideFuncNonDynamicProperty] : failed: caught "NSUnknownKeyException", "[<ClassInsideFuncNonDynamicProperty 0x10041d260> setValue:forUndefinedKey:]: this class is not key value coding-compliant for the key nonDynamicProperty."
(
	0   CoreFoundation                      0x00007fff8ee9503c __exceptionPreprocess + 172
	1   libobjc.A.dylib                     0x00007fff98f4076e objc_exception_throw + 43
	2   CoreFoundation                      0x00007fff8ee94bd9 -[NSException raise] + 9
	3   Foundation                          0x00007fff94294e7d -[NSObject(NSKeyValueCoding) setValue:forKey:] + 395
	4   testTests                           0x00000001000b45d7 _TTSf4g___TFC9testTests9testTests47testKVCandKVO_ClassInsideFuncNonDynamicPropertyfS0_FT_T_ + 727
	5   testTests                           0x00000001000b3346 _TToFC9testTests9testTests47testKVCandKVO_ClassInsideFuncNonDynamicPropertyfS0_FT_T_ + 22
	6   CoreFoundation                      0x00007fff8ed6c7bc __invoking___ + 140
	7   CoreFoundation                      0x00007fff8ed6c612 -[NSInvocation invoke] + 290
	8   XCTest                              0x000000010071399c -[XCTestCase invokeTest] + 253
	9   XCTest                              0x0000000100713b9d -[XCTestCase performTest:] + 150
	10  XCTest                              0x000000010071c6e0 -[XCTest run] + 257
	11  XCTest                              0x00000001007128ab -[XCTestSuite performTest:] + 379
	12  XCTest                              0x000000010071c6e0 -[XCTest run] + 257
	13  XCTest                              0x00000001007128ab -[XCTestSuite performTest:] + 379
	14  XCTest                              0x000000010071c6e0 -[XCTest run] + 257
	15  XCTest                              0x00000001007128ab -[XCTestSuite performTest:] + 379
	16  XCTest                              0x000000010071c6e0 -[XCTest run] + 257
	17  XCTest                              0x000000010070f8a9 __25-[XCTestDriver _runSuite]_block_invoke + 56
	18  XCTest                              0x000000010071b34d -[XCTestObservationCenter _observeTestExecutionForBlock:] + 162
	19  XCTest                              0x000000010070f7e0 -[XCTestDriver _runSuite] + 269
	20  XCTest                              0x00000001007103c9 -[XCTestDriver _checkForTestManager] + 678
	21  XCTest                              0x000000010071f580 +[XCTestProbe runTests:] + 182
	22  xctest                              0x0000000100001266 xctest + 4710
	23  xctest                              0x00000001000015e2 xctest + 5602
	24  xctest                              0x0000000100000ee3 xctest + 3811
	25  libdyld.dylib                       0x00007fff906925c9 start + 1
	26  ???                                 0x000000000000000a 0x0 + 10
)
Test Case '-[testTests.testTests testKVCandKVO_ClassInsideFuncNonDynamicProperty]' failed (0.070 seconds).
Test Case '-[testTests.testTests testKVCandKVO_ClassOutsideFuncDynamicProperty]' started.

==== testKVCandKVO_ClassOutsideFuncDynamicProperty()
dynamicProperty = [kind: 1, new: 0]
dynamicProperty = [kind: 1, new: 2]
before setValue: Optional(2)
after setValue: Optional(0)
Test Case '-[testTests.testTests testKVCandKVO_ClassOutsideFuncDynamicProperty]' passed (0.001 seconds).
Test Case '-[testTests.testTests testKVCandKVO_ClassOutsideFuncNonDynamicProperty]' started.

==== testKVCandKVO_ClassOutsideFuncNonDynamicProperty()
nonDynamicProperty = [kind: 1, new: 0]
before setValue: Optional(2)
after setValue: Optional(0)
Test Case '-[testTests.testTests testKVCandKVO_ClassOutsideFuncNonDynamicProperty]' passed (0.000 seconds).
Test Suite 'testTests' failed at 2015-04-07 07:14:16 +0000.
	 Executed 4 tests, with 1 failure (1 unexpected) in 0.073 (0.074) seconds
Test Suite 'testTests.xctest' failed at 2015-04-07 07:14:16 +0000.
	 Executed 4 tests, with 1 failure (1 unexpected) in 0.073 (0.075) seconds
Test Suite 'All tests' failed at 2015-04-07 07:14:16 +0000.
	 Executed 4 tests, with 1 failure (1 unexpected) in 0.073 (0.076) seconds

Objective-Cから利用可能なSwiftのクラスは、ファイルスコープ定義のものだけなので、Objective-C利用を前提としたKVC/KVOの互換コードは、ファイルスコープ定義のものにしか使われていないと想像。
Objective-CからSwiftのクラスを利用する際には、dynamicの有無は関係ない。