codingSrategy fix and sample

Author: evermeer

README.md

@@ -189,8 +189,6 @@ perl -p -e "s/($KEYWORDS)/ warning: \$1/"
 
 You can install this by adding the following line to your Podfile:
 
-⚠️WARNING: Swift 4 or later is required ⚠️
-
 ```
 pod "Stuff/Codable"
 ```
@@ -216,7 +214,7 @@ And here you can see how you can use these Stuff/Codable functions:
 
 ```swift
 func test() {
-   let initialObject = TestCodable(naam: "Edwin", id: 1)
+   let initialObject = TestCodable(naam: "Edwin", id: 1, testField: "tst")
 
    guard let json = initialObject.toJsonString() else {
       print("Could not create json from object")
@@ -245,11 +243,18 @@ func test() {
       return
    }
    print("inner object from json \(String(describing: innerObject))")
+   
+   guard let custom = try TestCodable(json: "{\"Naam\":\"UpperN\", \"Id\":5, \"Test_field\":\"lowerSnake\"}", keyPath: nil, codingStrategy: customCodingStragegy) else {
+      print("Could not custom case convert")
+      return
+   }
+   print("read object with custom key coding from json to \(String(describing:    
 }
 
 struct TestCodable : Codable {
    var naam: String?
    var id: Int?
+    var testField: String?    
 }
 ```
 

Source/Codable/Codable.swift

@@ -10,6 +10,28 @@ enum CodingError : Error {
     case RuntimeError(String)
 }
 
+struct AnyKey: CodingKey {
+    var stringValue: String
+    var intValue: Int?
+
+    init(stringValue: String) {
+        self.stringValue = stringValue
+        self.intValue = nil
+    }
+
+    init(intValue: Int) {
+        self.stringValue = String(intValue)
+        self.intValue = intValue
+    }
+}
+
+public var customCodingStragegy: JSONDecoder.KeyDecodingStrategy = .custom { keys in
+    let lastComponent = keys.last!.stringValue
+    let snakeCased = lastComponent.split(separator: "_").map { $0.prefix(1).uppercased() + $0.dropFirst() }.reduce("") { $0 + $1}
+    let lowerFirst = snakeCased.prefix(1).lowercased() + snakeCased.dropFirst()
+    return AnyKey(stringValue: lowerFirst)
+}
+
 public extension Encodable {
     /**
      Convert this object to json data
@@ -94,9 +116,9 @@ public extension Decodable {
      - parameter json: The json string
      - parameter keyPath: for if you want something else than the root object
      */
-    init(json: String, keyPath: String? = nil) throws {
+    init(json: String, keyPath: String? = nil, codingStrategy: JSONDecoder.KeyDecodingStrategy = .convertFromSnakeCase) throws {
         guard let data = json.data(using: .utf8) else { throw CodingError.RuntimeError("cannot create data from string") }
-        try self.init(data: data, keyPath: keyPath)
+        try self.init(data: data, keyPath: keyPath, codingStrategy: codingStrategy)
     }
 
     /**
@@ -105,9 +127,9 @@ public extension Decodable {
      - parameter data: The json data
      - parameter keyPath: for if you want something else than the root object
      */
-    init(data: Data, keyPath: String? = nil, codingStragegy: JSONDecoder.KeyDecodingStrategy = .convertFromSnakeCase) throws {
+    init(data: Data, keyPath: String? = nil, codingStrategy: JSONDecoder.KeyDecodingStrategy = .convertFromSnakeCase) throws {
         let decoder = JSONDecoder()
-        decoder.keyDecodingStrategy = .convertFromSnakeCase
+        decoder.keyDecodingStrategy = codingStrategy
         if let keyPath = keyPath {
             let topLevel = try JSONSerialization.jsonObject(with: data, options: JSONSerialization.ReadingOptions.mutableContainers)
             guard let nestedJson = (topLevel as AnyObject).value(forKeyPath: keyPath) else { throw CodingError.RuntimeError("Cannot decode data to object")  }

Stuff.podspec

@@ -1,6 +1,6 @@
 Pod::Spec.new do |s|
   s.name         = "Stuff"
-  s.version      = "0.6.1"
+  s.version      = "0.7.0"
   s.summary      = "Too small for a library, too important to just forget"
 
   s.description  = <<-EOS

StuffTests/CodableStuffTests.swift

@@ -13,7 +13,7 @@ import XCTest
 class CodingStuffTests: XCTestCase {
 
     func test() {
-        let initialObject = TestCodable(naam: "Edwin", id: 1)
+        let initialObject = TestCodable(naam: "Edwin", id: 1, testField: "tst")
 
         guard let json = initialObject.toJsonString() else {
             print("Could not create json from object")
@@ -46,7 +46,16 @@ class CodingStuffTests: XCTestCase {
             return
         }
         print("inner object from json \(String(describing: innerObject))")
-        
+
+        do {
+            let custom = try TestCodable(json: "{\"Naam\":\"UN\", \"Id\":5, \"Test_field\":\"tst\"}", keyPath: nil, codingStrategy: customCodingStragegy)
+            print("read object with custom key coding from json to \(String(describing: custom))")
+        } catch {
+            print("Could not custom case convert \(error)")
+            assertionFailure()
+            return
+        }
+
         do {
             try initialObject.saveToDocuments("myFile.dat")
         } catch {
@@ -80,4 +89,5 @@ class CodingStuffTests: XCTestCase {
 struct TestCodable : Codable {
     var naam: String?
     var id: Int?
+    var testField: String?
 }