Add nested key path setter support

iwasrobbed · Mar 27, 2017 · c7c21ab · c7c21ab
1 parent e5b4fbf
commit c7c21ab
Show file tree

Hide file tree

Showing 4 changed files with 80 additions and 16 deletions.
diff --git a/LazyObject.xcodeproj/project.pbxproj b/LazyObject.xcodeproj/project.pbxproj
@@ -179,20 +179,20 @@
 		D4BCBAD31CF0D2530014D111 /* Tests */ = {
 			isa = PBXGroup;
 			children = (
-				D4418C7F1CF4EE7E001A9E94 /* DateTests.swift */,
+				D4A0F2451E07818600536FD0 /* BoolConversionTests.swift */,
 				D4418C811CF5E37F001A9E94 /* DateFormatterTests.swift */,
+				D4418C7F1CF4EE7E001A9E94 /* DateTests.swift */,
+				D4A0F2421E07815700536FD0 /* DoubleConversionTests.swift */,
 				D4BCBAEF1CF0D9020014D111 /* ErrorTests.swift */,
+				D4A0F23F1E0780D200536FD0 /* FloatConversionTests.swift */,
 				D45BFC3C1CF107BB00914459 /* InstantiationTests.swift */,
+				D4A0F2391E07802800536FD0 /* IntConversionTests.swift */,
 				D4BCBAF11CF0E4810014D111 /* LazyValueTests.swift */,
 				D4BCBAED1CF0D8EE0014D111 /* NSNumberConversionTests.swift */,
-				D4A0F23C1E07809D00536FD0 /* UIntConversionTests.swift */,
-				D4A0F2391E07802800536FD0 /* IntConversionTests.swift */,
-				D4A0F23F1E0780D200536FD0 /* FloatConversionTests.swift */,
-				D4A0F2421E07815700536FD0 /* DoubleConversionTests.swift */,
-				D4A0F2451E07818600536FD0 /* BoolConversionTests.swift */,
 				D49964E21CF36C8400650211 /* NSURLConversionTests.swift */,
 				D4BCBAEB1CF0D8950014D111 /* NullValueTests.swift */,
 				D40AD0AD1CF3B3C70093B743 /* SetterTests.swift */,
+				D4A0F23C1E07809D00536FD0 /* UIntConversionTests.swift */,
 				D4BCBAD51CF0D2530014D111 /* ValueTypeTests.swift */,
 			);
 			path = Tests;

diff --git a/Source/Extensions/NSDictionary+Lazy.swift b/Source/Extensions/NSDictionary+Lazy.swift
@@ -8,6 +8,8 @@
 
 import Foundation
 
+// MARK: - Pruning
+
 extension NSDictionary {
 
     /**
@@ -24,6 +26,12 @@ extension NSDictionary {
         return nonNullDictionary
     }
 
+}
+
+// MARK: - KVO Safety
+
+extension NSDictionary {
+
     /**
      Safely returns a value at the given key / key path if it exists
      
@@ -39,5 +47,41 @@ extension NSDictionary {
         }
         return object
     }
+
+}
 
+extension NSMutableDictionary {
+
+    /// Safely sets a value for a given key path, making existing nodes mutable if necessary
+    ///
+    /// - Parameters:
+    ///   - value: The value to set
+    ///   - keyPath: The key path to use
+    func lazySet(value: Any?, forKeyPath keyPath: String) {
+        _makeDirectoriesMutable(forKeyPath: keyPath)
+        setValue(value, forKeyPath: keyPath)
+    }
+
+    /// Recursively traverses the given key path and turns any `NSDictionary` objects it finds into `NSMutableDictionary` equivalents so we can write back to the key path
+    ///
+    /// - Parameter keyPath: The key path to search
+    fileprivate func _makeDirectoriesMutable(forKeyPath keyPath: String) {
+        let keys = keyPath.characters.split(separator: ".").map(String.init)
+        var currentKeyPath: String?
+
+        keys.forEach { key in
+            if currentKeyPath != nil {
+                let nextKeyPathAddition = String(format: ".%@", key)
+                currentKeyPath = currentKeyPath?.appending(nextKeyPathAddition)
+            } else {
+                currentKeyPath = key
+            }
+
+            if let currentKeyPath = currentKeyPath, let value = lazyValue(forKeyPath: currentKeyPath) as? NSDictionary {
+                setValue(value.mutableCopy(), forKeyPath: currentKeyPath)
+            }
+        }
+
+    }
+
 }
diff --git a/Source/LazyMapping.swift b/Source/LazyMapping.swift
@@ -172,11 +172,7 @@ public extension LazyMapping {
      - parameter keyPath: The key / key path to set the value for
      */
     public func setObject(_ object: Any?, keyPath: String) {
-        if let object = object {
-            dictionary.setObject(object, forKey: keyPath as NSCopying)
-        } else {
-            dictionary.removeObject(forKey: keyPath)
-        }
+        dictionary.lazySet(value: object, forKeyPath: keyPath)
     }
 
 }
@@ -198,7 +194,7 @@ private extension LazyMapping {
             throw LazyMappingError.conversionError(keyPath: keyPath, value: value, type: T.self)
         }
 
-        dictionary.setValue(typedValue, forKeyPath: keyPath)
+        dictionary.lazySet(value: typedValue, forKeyPath: keyPath)
         return typedValue
     }
 
@@ -215,7 +211,7 @@ private extension LazyMapping {
 
         let mappedArray = array.map { T(dictionary: $0, pruneNullValues: true) }
 
-        dictionary.setValue(mappedArray, forKeyPath: keyPath)
+        dictionary.lazySet(value: mappedArray, forKeyPath: keyPath)
         return mappedArray
     }
 
@@ -229,7 +225,7 @@ private extension LazyMapping {
 
         // Otherwise, try to convert it to the given type
         let transformedValue = try convert(value)
-        dictionary.setValue(transformedValue, forKeyPath: keyPath)
+        dictionary.lazySet(value: transformedValue, forKeyPath: keyPath)
         return transformedValue
     }
 

diff --git a/Tests/SetterTests.swift b/Tests/SetterTests.swift
@@ -20,13 +20,27 @@ final class SetterTests: XCTestCase {
                 setObject(newValue, setter: #function)
             }
         }
+        var nestedId: NSNumber? {
+            get {
+                return try? objectFor("nested.identifier")
+            }
+            set {
+                setObject(newValue, keyPath: "nested.identifier")
+            }
+        }
     }
-    let object = Object(dictionary: ["id": "42"])
+
+    let object = Object(dictionary: ["id": "42",
+                                     "nested": ["identifier": "24"]])
 
     func testSettingObjectByKeyPath() {
         XCTAssertTrue(object.id != 43)
         object.setObject(43, keyPath: "id")
         XCTAssertTrue(object.id == 43)
+
+        XCTAssertTrue(object.nestedId != 43)
+        object.nestedId = 43
+        XCTAssertTrue(object.nestedId == 43)
     }
 
     func testSettingObjectBySetter() {
@@ -35,12 +49,22 @@ final class SetterTests: XCTestCase {
         XCTAssertTrue(object.id == 44)
     }
 
-    func testRemovingObjectUsingNilValueForSetter() {
+    func testRemovingObjectUsingNilValueForNonNestedSetter() {
+        // Non-nested type
         object.id = 24
         XCTAssertTrue(object.id == 24)
 
         object.id = nil
         XCTAssertNil(object.id)
     }
+
+    func testRemovingObjectUsingNilValueForNestedSetter() {
+        // Nested type
+        object.nestedId = 42
+        XCTAssertTrue(object.nestedId == 42)
+
+        object.nestedId = nil
+        XCTAssertNil(object.nestedId)
+    }
 
 }