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@jarsen
Last active Nov 10, 2017
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import Foundation
//
// MARK: - JSONError Type
//
public enum JSONError: ErrorType, CustomStringConvertible {
case KeyNotFound(key: String)
case NullValue(key: String)
case TypeMismatch(expected: Any, actual: Any)
case TypeMismatchWithKey(key: String, expected: Any, actual: Any)
public var description: String {
switch self {
case let .KeyNotFound(key):
return "Key not found: \(key)"
case let .NullValue(key):
return "Null Value found at: \(key)"
case let .TypeMismatch(expected, actual):
return "Type mismatch. Expected type \(expected). Got '\(actual)'"
case let .TypeMismatchWithKey(key, expected, actual):
return "Type mismatch. Expected type \(expected) at key: \(key). Got '\(actual)'"
}
}
}
//
// MARK: - JSONValue
//
public protocol JSONValue {
typealias Value = Self
static func JSONValue(object: Any) throws -> Value
}
extension JSONValue {
public static func JSONValue(object: Any) throws -> Value {
guard let objectValue = object as? Value else {
throw JSONError.TypeMismatch(expected: Value.self, actual: object.dynamicType)
}
return objectValue
}
}
//
// MARK: - JSONValue Implementations
//
extension String: JSONValue {}
extension Int: JSONValue {}
extension UInt: JSONValue {}
extension Float: JSONValue {}
extension Double: JSONValue {}
extension Bool: JSONValue {}
extension Array where Element: JSONValue {
public static func JSONValue(object: Any) throws -> [Element] {
guard let anyArray = object as? [AnyObject] else {
throw JSONError.TypeMismatch(expected: self, actual: object.dynamicType)
}
return try anyArray.map { try Element.JSONValue($0) as! Element }
}
}
extension Dictionary: JSONValue {
public static func JSONValue(object: Any) throws -> [Key: Value] {
guard let objectValue = object as? [Key: Value] else {
throw JSONError.TypeMismatch(expected: self, actual: object.dynamicType)
}
return objectValue
}
}
extension NSURL: JSONValue {
public static func JSONValue(object: Any) throws -> NSURL {
guard let urlString = object as? String, objectValue = NSURL(string: urlString) else {
throw JSONError.TypeMismatch(expected: self, actual: object.dynamicType)
}
return objectValue
}
}
extension JSONObject: JSONValue {
public static func JSONValue(object: Any) throws -> JSONObject {
guard let dictionary = object as? JSONDictionary else {
throw JSONError.TypeMismatch(expected: self, actual: object.dynamicType)
}
return JSONObject(dictionary: dictionary)
}
}
//
// MARK: - JSONObjectConvertible
//
public protocol JSONObjectConvertible : JSONValue {
typealias ConvertibleType = Self
init(json: JSONObject) throws
}
extension JSONObjectConvertible {
public static func JSONValue(object: Any) throws -> ConvertibleType {
guard let jsonDict = object as? JSONDictionary else {
throw JSONError.TypeMismatch(expected: JSONDictionary.self, actual: object.dynamicType)
}
let json = JSONObject(dictionary: jsonDict)
guard let value = try self.init(json: json) as? ConvertibleType else {
throw JSONError.TypeMismatch(expected: ConvertibleType.self, actual: object.dynamicType)
}
return value
}
}
//
// MARK: - JSONObjectDeconvertible
//
public protocol JSONDictionaryConvertible {
var jsonDictionary: JSONDictionary { get }
}
//
// MARK: - JSONObject
//
public typealias JSONDictionary = [String: AnyObject]
public struct JSONObject {
public var dictionary: JSONDictionary
public init?(data: NSData, options: NSJSONReadingOptions = []) throws {
guard let dict = try NSJSONSerialization.JSONObjectWithData(data, options: options) as? JSONDictionary else {
return nil
}
self.init(dictionary: dict)
}
public init(dictionary: JSONDictionary) {
self.dictionary = dictionary
}
private func anyForKey(key: String) throws -> Any {
let pathComponents = key.characters.split(".").map(String.init)
var accumulator: Any = dictionary
for component in pathComponents {
if let componentData = accumulator as? JSONDictionary, value = componentData[component] {
accumulator = value
continue
}
throw JSONError.KeyNotFound(key: key)
}
if let _ = accumulator as? NSNull {
throw JSONError.NullValue(key: key)
}
return accumulator
}
public func valueForKey<A: JSONValue>(key: String) throws -> A {
let any = try anyForKey(key)
guard let result = try A.JSONValue(any) as? A else {
throw JSONError.TypeMismatchWithKey(key: key, expected: A.self, actual: any.dynamicType)
}
return result
}
public func valueForKey<A: JSONValue>(key: String) throws -> [A] {
let any = try anyForKey(key)
return try Array<A>.JSONValue(any)
}
public func valueForKey<A: JSONValue>(key: String) throws -> A? {
do {
return try self.valueForKey(key) as A
}
catch JSONError.KeyNotFound {
return nil
}
catch JSONError.NullValue {
return nil
}
catch {
throw error
}
}
}
extension JSONObject: CustomStringConvertible {
public var description: String {
return dictionary.description
}
}
extension JSONObject: CustomDebugStringConvertible {
public var debugDescription: String {
return dictionary.debugDescription
}
}
//extension JSONObject: DictionaryLiteralConvertible {
//
//}
//
// MARK: - Tests
//
public struct User : JSONObjectConvertible, JSONDictionaryConvertible {
public let name: String
public let email: String
public init(json: JSONObject) throws {
name = try json.valueForKey("name")
email = try json.valueForKey("email")
}
public var jsonDictionary: JSONDictionary {
return [
"name": name,
"email": email
]
}
}
var json = JSONObject(dictionary: ["url": "http://apple.com", "foo": (2 as NSNumber), "str": "Hello, World!", "array": [1,2,3,4,7], "object": ["foo": (3 as NSNumber), "str": "Hello, World!"], "bool": (true as NSNumber), "urls": ["http://apple.com", "http://google.com"], "user": ["name": "Jason", "email": "email@email.com"], "users": [["name": "Jason", "email": "email@email.com"], ["name": "Bob", "email": "bob@email.com"]]])
do {
var str: String = try json.valueForKey("str")
// var foo1: String = try json.valueForKey("foo")
var foo2: Int = try json.valueForKey("foo")
var foo3: Int? = try json.valueForKey("foo")
var foo4: Int? = try json.valueForKey("bar")
var arr: [Int] = try json.valueForKey("array")
var obj: JSONObject? = try json.valueForKey("object")
let innerfoo: Int = try obj!.valueForKey("foo")
let innerfoo2: Int = try json.valueForKey("object.foo")
let bool: Bool = try json.valueForKey("bool")
let url: NSURL = try json.valueForKey("url")
let urls: [NSURL] = try json.valueForKey("urls")
let user: User = try json.valueForKey("user")
user.name
let users: [User] = try json.valueForKey("users")
users.first?.name
}
catch {
print("\(error)")
}
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