- added shouldIncludeNilValues as member variable of Mapper and Map

- only printing null when property is set to true
- added test

Sources/ImmutableMappable.swift

@@ -242,7 +242,7 @@ public extension Mapper where N: ImmutableMappable {
 internal extension Mapper where N: BaseMappable {
 
 	internal func mapOrFail(JSON: [String: Any]) throws -> N {
-		let map = Map(mappingType: .fromJSON, JSON: JSON, context: context)
+		let map = Map(mappingType: .fromJSON, JSON: JSON, context: context, shouldIncludeNilValues: shouldIncludeNilValues)
 
 		// Check if object is ImmutableMappable, if so use ImmutableMappable protocol for mapping
 		if let klass = N.self as? ImmutableMappable.Type,

Sources/Map.swift

@@ -45,14 +45,17 @@ public final class Map {
 	var keyIsNested = false
 	public internal(set) var nestedKeyDelimiter: String = "."
 	public var context: MapContext?
+	public var shouldIncludeNilValues = false
 
 	let toObject: Bool // indicates whether the mapping is being applied to an existing object
 
-	public init(mappingType: MappingType, JSON: [String: Any], toObject: Bool = false, context: MapContext? = nil) {
+	public init(mappingType: MappingType, JSON: [String: Any], toObject: Bool = false, context: MapContext? = nil, shouldIncludeNilValues: Bool = false) {
+
 		self.mappingType = mappingType
 		self.JSON = JSON
 		self.toObject = toObject
 		self.context = context
+		self.shouldIncludeNilValues = shouldIncludeNilValues
 	}
 
 	/// Sets the current mapper value and key.
@@ -133,10 +136,10 @@ private func valueFor(_ keyPathComponents: ArraySlice<String>, dictionary: [Stri
 		let object = dictionary[keyPath]
 		if object is NSNull {
 			return (true, nil)
-		} else if let dict = object as? [String: Any] , keyPathComponents.count > 1 {
+		} else if keyPathComponents.count > 1, let dict = object as? [String: Any] {
 			let tail = keyPathComponents.dropFirst()
 			return valueFor(tail, dictionary: dict)
-		} else if let array = object as? [Any] , keyPathComponents.count > 1 {
+		} else if keyPathComponents.count > 1, let array = object as? [Any] {
 			let tail = keyPathComponents.dropFirst()
 			return valueFor(tail, array: array)
 		} else {
@@ -159,19 +162,19 @@ private func valueFor(_ keyPathComponents: ArraySlice<String>, array: [Any]) ->
 	if let keyPath = keyPathComponents.first,
 		let index = Int(keyPath) , index >= 0 && index < array.count {
 
-			let object = array[index]
-			
-			if object is NSNull {
-				return (true, nil)
-			} else if let array = object as? [Any] , keyPathComponents.count > 1 {
-				let tail = keyPathComponents.dropFirst()
-				return valueFor(tail, array: array)
-			} else if let dict = object as? [String: Any] , keyPathComponents.count > 1 {
-				let tail = keyPathComponents.dropFirst()
-				return valueFor(tail, dictionary: dict)
-			} else {
-				return (true, object)
-			}
+		let object = array[index]
+
+		if object is NSNull {
+			return (true, nil)
+		} else if keyPathComponents.count > 1, let array = object as? [Any]  {
+			let tail = keyPathComponents.dropFirst()
+			return valueFor(tail, array: array)
+		} else if  keyPathComponents.count > 1, let dict = object as? [String: Any] {
+			let tail = keyPathComponents.dropFirst()
+			return valueFor(tail, dictionary: dict)
+		} else {
+			return (true, object)
+		}
 	}
 
 	return (false, nil)

Sources/Mapper.swift

@@ -37,9 +37,11 @@ public enum MappingType {
 public final class Mapper<N: BaseMappable> {
 
 	public var context: MapContext?
+	public var shouldIncludeNilValues = false
 
-	public init(context: MapContext? = nil){
+	public init(context: MapContext? = nil, shouldIncludeNilValues: Bool = false){
 		self.context = context
+		self.shouldIncludeNilValues = shouldIncludeNilValues
 	}
 
 	// MARK: Mapping functions that map to an existing object toObject
@@ -65,7 +67,7 @@ public final class Mapper<N: BaseMappable> {
 	/// Usefull for those pesky objects that have crappy designated initializers like NSManagedObject
 	public func map(JSON: [String: Any], toObject object: N) -> N {
 		var mutableObject = object
-		let map = Map(mappingType: .fromJSON, JSON: JSON, toObject: true, context: context)
+		let map = Map(mappingType: .fromJSON, JSON: JSON, toObject: true, context: context, shouldIncludeNilValues: shouldIncludeNilValues)
 		mutableObject.mapping(map: map)
 		return mutableObject
 	}
@@ -92,7 +94,7 @@ public final class Mapper<N: BaseMappable> {
 
 	/// Maps a JSON dictionary to an object that conforms to Mappable
 	public func map(JSON: [String: Any]) -> N? {
-		let map = Map(mappingType: .fromJSON, JSON: JSON, context: context)
+		let map = Map(mappingType: .fromJSON, JSON: JSON, context: context, shouldIncludeNilValues: shouldIncludeNilValues)
 
 		if let klass = N.self as? StaticMappable.Type { // Check if object is StaticMappable
 			if var object = klass.objectForMapping(map: map) as? N {
@@ -272,7 +274,7 @@ extension Mapper {
 	///Maps an object that conforms to Mappable to a JSON dictionary <String, Any>
 	public func toJSON(_ object: N) -> [String: Any] {
 		var mutableObject = object
-		let map = Map(mappingType: .toJSON, JSON: [:], context: context)
+		let map = Map(mappingType: .toJSON, JSON: [:], context: context, shouldIncludeNilValues: shouldIncludeNilValues)
 		mutableObject.mapping(map: map)
 		return map.JSON
 	}

Sources/ToJSON.swift

@@ -97,7 +97,7 @@ internal final class ToJSON {
 	class func optionalBasicType<N>(_ field: N?, map: Map) {
 		if let field = field {
 			basicType(field, map: map)
-		} else {
+		} else if map.shouldIncludeNilValues {
 			basicType(NSNull(), map: map)  //If BasicType is nil, emil NSNull into the JSON output
 		}
 	}

Tests/ObjectMapperTests/BasicTypesTestsToJSON.swift

@@ -46,6 +46,18 @@ class BasicTypesTestsToJSON: XCTestCase {
 
 	// MARK: Test mapping to JSON and back (basic types: Bool, Int, Double, Float, String)
 
+	func testShouldIncludeNilValues(){
+		let object = BasicTypes()
+
+		let JSONWithNil = Mapper<BasicTypes>(shouldIncludeNilValues: true).toJSONString(object, prettyPrint: true)
+		let JSONWithoutNil = Mapper<BasicTypes>(shouldIncludeNilValues: false).toJSONString(object, prettyPrint: true)
+
+		//TODO This test could be improved
+		XCTAssertNotNil(JSONWithNil)
+		XCTAssertTrue((JSONWithNil!.characters.count) > 5)
+		XCTAssertTrue((JSONWithNil!.characters.count) != (JSONWithoutNil!.characters.count))
+	}
+
 	func testMappingBoolToJSON(){
 		let value: Bool = true
 		let object = BasicTypes()