Merge pull request #63 from fadyyecob/feature/decryption-single-property

Moved to a single property for decryption

Example/JustTweak/Accessors/GeneratedTweakAccessor+Constants.swift

@@ -17,6 +17,7 @@ extension GeneratedTweakAccessor {
         static let displayGreenView = "display_green_view"
         static let displayRedView = "display_red_view"
         static let displayYellowView = "display_yellow_view"
+        static let encryptedAnswerToTheUniverse = "encrypted_answer_to_the_universe"
         static let greetOnAppDidBecomeActive = "greet_on_app_did_become_active"
         static let labelText = "label_text"
         static let redViewAlphaComponent = "red_view_alpha_component"

Example/JustTweak/Accessors/GeneratedTweakAccessor.swift

@@ -29,6 +29,11 @@ class GeneratedTweakAccessor {
         set { tweakManager.set(newValue, feature: Features.uiCustomization, variable: Variables.displayYellowView) }
     }
 
+    var definitiveAnswerEncrypted: String {
+        get { tweakManager.tweakWith(feature: Features.general, variable: Variables.encryptedAnswerToTheUniverse)?.stringValue ?? "" }
+        set { tweakManager.set(newValue, feature: Features.general, variable: Variables.encryptedAnswerToTheUniverse) }
+    }
+
     var isTapGestureToChangeColorEnabled: Bool {
         get { tweakManager.tweakWith(feature: Features.general, variable: Variables.tapToChangeColorEnabled)?.boolValue ?? false }
         set { tweakManager.set(newValue, feature: Features.general, variable: Variables.tapToChangeColorEnabled) }

Example/JustTweak/Code/AppDelegate.swift

@@ -60,6 +60,11 @@ class AppDelegate: UIResponder, UIApplicationDelegate {
 
         let tweakManager = TweakManager(tweakProviders: tweakProviders)
         tweakManager.useCache = true
+
+        tweakManager.decryptionClosure = { tweak in
+            String((tweak.value.stringValue ?? "").reversed())
+        }
+
         return tweakManager
     }
 }

Example/JustTweak/Code/ViewController.swift

@@ -32,6 +32,12 @@ class ViewController: UIViewController {
             print("Tweak changed: \(tweak)")
             self?.updateView()
         }
+        addEncryptedMeaningOfLifeTapGesture()
+    }
+
+    private func addEncryptedMeaningOfLifeTapGesture() {
+        let tapGestureRecognizer = UILongPressGestureRecognizer(target: self, action: #selector(showEncryptedMeaningOfLife))
+        view.addGestureRecognizer(tapGestureRecognizer)
     }
 
     internal func updateView() {
@@ -60,6 +66,14 @@ class ViewController: UIViewController {
         present(alertController, animated: true, completion: nil)
     }
 
+    @objc func showEncryptedMeaningOfLife() {
+        let alertController = UIAlertController(title: "Encrypted Meaning of Life",
+                                                message: String(describing: tweakAccessor.definitiveAnswerEncrypted),
+                                                preferredStyle: .alert)
+        alertController.addAction(UIAlertAction(title: "OK", style: .default))
+        present(alertController, animated: true)
+    }
+
     @objc internal func changeViewColor() {
         func randomColorValue() -> CGFloat {
             return CGFloat(arc4random() % 255) / 255.0

Example/JustTweak/TweakProviders/LocalTweaks_example.json

@@ -36,6 +36,14 @@
     }
   },
   "general": {
+    "encrypted_answer_to_the_universe": {
+      "Title": "Encrypted definitive answer",
+      "Description": "Encrypted answer to the Ultimate Question of Life, the Universe, and Everything",
+      "Group": "General",
+      "Value": "24 ton yletinifeD",
+      "GeneratedPropertyName": "definitiveAnswerEncrypted",
+      "Encrypted": true
+    },
     "answer_to_the_universe": {
       "Title": "Definitive answer",
       "Description": "Answer to the Ultimate Question of Life, the Universe, and Everything",

Example/Tests/Core/TweakManagerTests.swift

@@ -90,25 +90,19 @@ class TweakManagerTests: XCTestCase {
     }
 
     func testTweakManagerDecryption() throws {
-        var mutableTweakProvider = try XCTUnwrap(tweakManager.mutableTweakProvider)
-        let feature = "password"
-        let variable = "variable"
+        let url = try XCTUnwrap(Bundle.main.url(forResource: "LocalTweaks_example", withExtension: "json"))
 
-        let encodedString = try XCTUnwrap("my secret password".data(using: .utf8)?.base64EncodedString())
+        tweakManager.tweakProviders.append(LocalTweakProvider(jsonURL: url))
 
-        mutableTweakProvider.set(encodedString, feature: feature, variable: variable)
-        mutableTweakProvider.decryptionClosure = { tweak in
-            let data = Data(base64Encoded: tweak.stringValue ?? "").map {
-                String(data: $0, encoding: .utf8)
-            } ?? ""
-
-            return data ?? ""
+        tweakManager.decryptionClosure = { tweak in
+            String((tweak.value.stringValue ?? "").reversed())
         }
 
+        let feature = "general"
+        let variable = "encrypted_answer_to_the_universe"
         let tweak = tweakManager.tweakWith(feature: feature, variable: variable)
 
-        XCTAssertEqual("bXkgc2VjcmV0IHBhc3N3b3Jk", tweak?.stringValue)
-        XCTAssertEqual("my secret password", tweak?.decryptedValue?.stringValue)
+        XCTAssertEqual("Definitely not 42", tweak?.stringValue)
     }
 
     func testSetTweakManagerDecryptionClosureThenDecryptionClosureIsSetForProviders() throws {

JustTweak/Classes/DTOs/Tweak.swift

@@ -11,7 +11,6 @@ public struct Tweak {
     public let variable: String
 
     public let value: TweakValue
-    public let decryptedValue: TweakValue?
 
     public let title: String?
     public let desc: String?
@@ -41,16 +40,14 @@ public struct Tweak {
                 title: String? = nil,
                 description: String? = nil,
                 group: String? = nil,
-                source: String? = nil,
-                decryptedValue: TweakValue? = nil) {
+                source: String? = nil) {
         self.feature = feature
         self.variable = variable
         self.value = value
         self.title = title
         self.desc = description
         self.group = group
         self.source = source
-        self.decryptedValue = decryptedValue
     }
 
     func mutatedCopy(feature: String? = nil,
@@ -59,16 +56,14 @@ public struct Tweak {
                      title: String? = nil,
                      description: String? = nil,
                      group: String? = nil,
-                     source: String? = nil,
-                     decryptedValue: TweakValue? = nil) -> Self {
+                     source: String? = nil) -> Self {
         Self(feature: feature ?? self.feature,
              variable: variable ?? self.variable,
              value: value ?? self.value,
              title: title ?? self.title,
              description: description ?? self.desc,
              group: group ?? self.group,
-             source: source ?? self.source,
-             decryptedValue: decryptedValue ?? self.decryptedValue)
+             source: source ?? self.source)
     }
 }
 

JustTweak/Classes/TweakManager.swift

@@ -93,19 +93,17 @@ extension TweakManager: MutableTweakProvider {
                 if let tweak = tweakProvider.tweakWith(feature: feature, variable: variable) {
                     logClosure?("Tweak '\(tweak)' found in configuration \(tweakProvider))", .verbose)
 
-                    let tweakWithoutDecryptedValue = Tweak(feature: feature,
-                                                           variable: variable,
-                                                           value: tweak.value,
-                                                           title: tweak.title,
-                                                           group: tweak.group,
-                                                           source: "\(type(of: tweakProvider))")
-
-                    let decryptedValue = tweakProvider.decryptionClosure?(tweakWithoutDecryptedValue)
-                    result = tweakWithoutDecryptedValue.mutatedCopy(decryptedValue: decryptedValue)
+                    result = Tweak(feature: feature,
+                                   variable: variable,
+                                   value: tweak.value,
+                                   title: tweak.title,
+                                   group: tweak.group,
+                                   source: "\(type(of: tweakProvider))")
                     break
                 }
                 else {
-                    logClosure?("Tweak with identifier '\(variable)' NOT found in configuration \(tweakProvider))", .verbose)
+                    let logMessage = "Tweak with identifier '\(variable)' in configuration \(tweakProvider)) could NOT be found or has an invalid configuration"
+                    logClosure?(logMessage, .verbose)
                 }
             }
             if let result = result {

JustTweak/Classes/TweakProviders/LocalTweakProvider.swift

@@ -8,7 +8,7 @@ import Foundation
 final public class LocalTweakProvider {
 
     private enum EncodingKeys : String {
-        case Title, Description, Group, Value
+        case Title, Description, Group, Value, Encrypted
     }
 
     private let configurationFile: [String : [String : [String : AnyObject]]]
@@ -66,6 +66,7 @@ extension LocalTweakProvider: TweakProvider {
         let description = entry[EncodingKeys.Description.rawValue] as? String
         let group = entry[EncodingKeys.Group.rawValue] as? String
         let value = tweakValueFromJSONObject(entry[EncodingKeys.Value.rawValue])
+        let isEncrypted = (entry[EncodingKeys.Encrypted.rawValue] as? Bool) ?? false
 
         let tweak = Tweak(feature: feature,
                           variable: variable,
@@ -74,6 +75,16 @@ extension LocalTweakProvider: TweakProvider {
                           description: description,
                           group: group)
 
-        return tweak.mutatedCopy(decryptedValue: decryptionClosure?(tweak))
+        if isEncrypted {
+            guard let decryptionClosure = decryptionClosure else {
+                // The configuration is not correct, it's encrypted, but there's no way to decrypt
+                // So return nil to indicate an error. Should be changed to a throwing function in the future
+                return nil
+            }
+
+            return tweak.mutatedCopy(value: decryptionClosure(tweak))
+        } else {
+            return tweak
+        }
     }
 }

JustTweak/Classes/TweakProviders/UserDefaultsTweakProvider.swift

@@ -31,15 +31,13 @@ extension UserDefaultsTweakProvider: TweakProvider {
         let userDefaultsValue = userDefaults.object(forKey: userDefaultsKey) as AnyObject?
         guard let value = updateUserDefaults(userDefaultsValue) else { return nil }
 
-        let tweak = Tweak(
+        return Tweak(
             feature: feature,
             variable: variable,
             value: value,
             title: nil,
             group: nil
         )
-
-        return tweak.mutatedCopy(decryptedValue: decryptionClosure?(tweak))
     }
 }
 

JustTweak/Classes/UI/TweakManager+Presentation.swift

@@ -21,16 +21,8 @@ extension TweakManager {
                                                     description: jsonTweak.desc,
                                                     group: jsonTweak.group)
 
-                        let decryptedTweakValue = decryptionClosure?(aggregatedTweak)
-
                         let key = "\(feature)-\(variable)"
-                        tweaks[key] = Tweak(feature: feature,
-                                            variable: variable,
-                                            value: tweak.value,
-                                            title: jsonTweak.title,
-                                            description: jsonTweak.desc,
-                                            group: jsonTweak.group,
-                                            decryptedValue: decryptedTweakValue)
+                        tweaks[key] = aggregatedTweak
                     }
                 }
             }

README.md

@@ -234,6 +234,31 @@ JustTweak comes with three tweak providers out-of-the-box:
 In addition, JustTweak defines `TweakProvider` and `MutableTweakProvider` protocols you can implement to create your own tweak provider to fit your needs. In the example project you can find some examples which you can use as a starting point.
 
 
+### Encryption or pre-processing (Advanced)
+
+JustTweak offers the ability to add a `decryptionClosure` to a `TweakProvider`. This closure takes the `Tweak` as input and returns a `TweakValue` as output. The closure allows you to do some preprocessing on your tweak which can e.g. be used to decrypt values. This can be used if you have an encrypted value in your tweaks JSON file as can be seen below:
+
+```json
+"encrypted_answer_to_the_universe": {
+  "Title": "Encrypted definitive answer",
+  "Description": "Encrypted answer to the Ultimate Question of Life, the Universe, and Everything",
+  "Group": "General",
+  "Value": "24 ton yletinifeD",
+  "GeneratedPropertyName": "definitiveAnswerEncrypted",
+  "Encrypted": true
+}
+```
+
+Note that you have to specify if the value is encrypted in your JSON file (with the `Encrypted` property) for the decryption closure to process the value. The decryption closure for the JSON above can be specified as follows:
+
+```swift
+tweakProvider.decryptionClosure = { tweak in
+    // decrypt `tweak.value` with your cypher of choice and return the decrypted value
+}
+```
+
+In this way, the tweak fetched from the tweak provider will have the decrypted value.
+
 ## License
 
 JustTweak is available under the Apache 2.0 license. See the LICENSE file for more info.

TweakAccessorGenerator/TweakAccessorGeneratorTests/Assets/Tweaks.json

@@ -32,6 +32,14 @@
     }
   },
   "general": {
+    "encrypted_answer_to_the_universe": {
+      "Title": "Encrypted definitive answer",
+      "Description": "Encrypted answer to the Ultimate Question of Life, the Universe, and Everything",
+      "Group": "General",
+      "Value": "24 ton yletinifeD",
+      "GeneratedPropertyName": "definitiveAnswerEncrypted",
+      "Encrypted": true
+    },
     "answer_to_the_universe": {
       "Title": "Definitive answer",
       "Description": "Answer to the Ultimate Question of Life, the Universe, and Everything",

TweakAccessorGenerator/TweakAccessorGeneratorTests/Suites/TweakLoaderTests.swift

@@ -34,6 +34,13 @@ class TweakLoaderTests: XCTestCase {
                   group: "General",
                   valueType: "Int",
                   propertyName: "definitiveAnswer"),
+            Tweak(feature: "general",
+                  variable: "encrypted_answer_to_the_universe",
+                  title: "Encrypted definitive answer",
+                  description: "Encrypted answer to the Ultimate Question of Life, the Universe, and Everything",
+                  group: "General",
+                  valueType: "String",
+                  propertyName: "definitiveAnswerEncrypted"),
             Tweak(feature: "general",
                   variable: "greet_on_app_did_become_active",
                   title: "Greet on app launch",