JSON parsing and factories

Example/MatrioskaExample/TileViewController.swift

@@ -9,7 +9,7 @@
 import UIKit
 import Matrioska
 
-struct TileConfig: MaterializableComponentMeta {
+struct TileConfig: ExpressibleByComponentMeta {
     let text: String?
     let color: UIColor?
 

Example/Podfile.lock

@@ -1,5 +1,5 @@
 PODS:
-  - Matrioska (0.1.0):
+  - Matrioska (0.1.0-alpha1):
     - SnapKit (~> 3.0)
   - SnapKit (3.0.2)
 
@@ -12,7 +12,7 @@ EXTERNAL SOURCES:
     :path: "../Matrioska.podspec"
 
 SPEC CHECKSUMS:
-  Matrioska: 872321eb578deb7af60323aa61126ee13e0d3fbd
+  Matrioska: b070c1ad36e64bdf7ab9d847033e2a5e4d2b8ec7
   SnapKit: 2e456761aa92d4d4067a7a5594c18769d451a8ad
 
 PODFILE CHECKSUM: b63a58336b9471a5dbe1ffe7ea7d0b94f6dbf667

Matrioska.xcodeproj/xcshareddata/xcschemes/Matrioska.xcscheme

@@ -1,6 +1,6 @@
 <?xml version="1.0" encoding="UTF-8"?>
 <Scheme
-   LastUpgradeVersion = "0810"
+   LastUpgradeVersion = "0820"
    version = "1.3">
    <BuildAction
       parallelizeBuildables = "YES"

Source/ComponentMeta.swift → Source/Components/ComponentMeta.swift

@@ -77,7 +77,8 @@ extension ExpressibleByComponentMeta {
     ///   or an already materialized meta object.
     /// - Returns: A materialized `ExpressibleByComponentMeta` object if the input represents correctly
     ///   the object to be materialized. 
-    /// - Note: This will return nil when `meta` is nil or will return the same `meta` object when `meta` is already a `Self` type.
+    /// - Note: This will return nil when `meta` is nil or 
+    ///   will return the same `meta` object when `meta` is already a `Self` type.
     public static func materialize(_ meta: ComponentMeta?) -> Self? {
         guard let meta = meta else {
             return nil

Source/Factories/JSONFactory.swift

@@ -0,0 +1,105 @@
+//
+//  JSONFactory.swift
+//  Matrioska
+//
+//  Created by Mathias Aichinger on 11/01/2017.
+//  Copyright © 2017 runtastic. All rights reserved.
+//
+
+import Foundation
+
+/// A JSONObject type
+public typealias JSONObject = [String: Any]
+
+/// An error type for JSONFactory
+///
+/// - missing: specifies that a mandatory key is missing
+enum JSONFactoryError: Error {
+    case missing(JSONObject, String)
+}
+
+/// A factory that wraps `Component` builder closures (ViewFactoryBuilder, 
+/// `WrapperFactoryBuilder` & `ClusterFactoryBuilder`) and uses them to produce `Component`s
+public final class JSONFactory {
+
+    private enum Key {
+        static let type = "type"
+        static let meta = "meta"
+        static let children = "children"
+    }
+
+    /// A factory closure to build a view `Component`
+    public typealias ViewFactoryBuilder = (ComponentMeta?) -> Component
+
+    /// A factory closure to build a wrapper `Component`
+    public typealias WrapperFactoryBuilder = (Component, ComponentMeta?) -> Component
+
+    /// A factory closure to build a cluster `Component`
+    public typealias ClusterFactoryBuilder = ([Component], ComponentMeta?) -> Component
+
+    private var viewFactory: [String: ViewFactoryBuilder] = [:]
+    private var wrapperFactory: [String: WrapperFactoryBuilder] = [:]
+    private var clusterFactory: [String: ClusterFactoryBuilder] = [:]
+
+    /// Initialize a new JSONFactory
+    public init() {
+        // Empty but needed to be initialized from other modules
+    }
+
+    /// Registers a new `ViewFactoryBuilder` which will be used when producing the component
+    ///
+    /// - Parameters:
+    ///   - type: a string identifying this factory type
+    ///   - factoryBuilder: a `ViewFactoryBuilder` to build a `Component`
+    public func register(with type: String,
+                         factoryBuilder: @escaping ViewFactoryBuilder) {
+        viewFactory[type] = factoryBuilder
+    }
+
+    /// Registers a new `WrapperFactoryBuilder` which will be used when producing the component
+    ///
+    /// - Parameters:
+    ///   - type: a string identifying this factory type
+    ///   - factoryBuilder: a `WrapperFactoryBuilder` to build a `Component`
+    public func register(with type: String,
+                         factoryBuilder: @escaping WrapperFactoryBuilder) {
+        wrapperFactory[type] = factoryBuilder
+    }
+
+    /// Registers a new `ClusterFactoryBuilder` which will be used when producing the component
+    ///
+    /// - Parameters:
+    ///   - type: a string identifying this factory type
+    ///   - factoryBuilder: a `ClusterFactoryBuilder` to build a `Component`
+    public func register(with type: String,
+                         factoryBuilder: @escaping ClusterFactoryBuilder) {
+        clusterFactory[type] = factoryBuilder
+    }
+
+    /// Produces a `Component` from a given `JSONObject`, which has one mandatory key: `type`
+    ///
+    /// - Parameter json: the `JSONObject` to be used
+    /// - Returns: An optional `Component`
+    /// - Throws: `JSONFactoryError` when a mandatory key is missing
+    public func component(from json: JSONObject) throws -> Component? {
+        guard let type = json[Key.type] as? String else {
+            throw JSONFactoryError.missing(json, Key.type)
+        }
+
+        let meta = json[Key.meta] as? JSONObject
+        let children = json[Key.children] as? [JSONObject] ?? []
+        let componentChildren = try children.flatMap { try component(from: $0) }
+        var componentResult: Component?
+
+        if let viewFactory = viewFactory[type] {
+            componentResult = viewFactory(meta)
+        } else if let wrapperFactory = wrapperFactory[type],
+                  let componentChild = componentChildren.first {
+            componentResult = wrapperFactory(componentChild, meta)
+        } else if let clusterFactory = clusterFactory[type] {
+            componentResult = clusterFactory(componentChildren, meta)
+        }
+
+        return componentResult
+    }
+}

Tests/.swiftlint.yml

@@ -1,19 +1,14 @@
 disabled_rules:
   - trailing_whitespace  # xcode add it by default, we might enable it and use autocorrect
   - function_body_length
+  - force_cast
+  - force_try
+  - force_unwrapping
+
+line_length: 200 # goal: 110
 
 opt_in_rules:
   - empty_count
-  - force_unwrapping
-  - private_outlet
-  - vertical_whitespace
-#  - missing_docs # broken
-  - closure_spacing
-  - conditional_returns_on_newline
-  - explicit_init
-  - overridden_super_call
-  - redundant_nil_coalesing
-#  - switch_case_on_newline # broken
 
 type_body_length:
   warning: 800
@@ -23,4 +18,4 @@ file_length:
   warning: 1000
   error: 1500
 
-reporter: "xcode" # reporter type (xcode, json, csv, checkstyle, junit)
+reporter: "xcode" # reporter type (xcode, json, csv, checkstyle, junit)

Tests/Assets/app_structure.json

@@ -0,0 +1,71 @@
+{
+    "structure": {
+        "type": "tabbar",
+        "meta": {
+            "default_tab_id": "main_tab"
+        },
+        "children": [
+                     {
+                     "type": "stack",
+                     "meta": {
+                     "tab_config": {
+                     "title": {
+                     "key": "history_title",
+                     "type": "localized_string"
+                     },
+                     "icon_name": "history_tab_icon"
+                     }
+                     },
+                     "children": [
+                                  {
+                                  "type": "table_view"
+                                  },
+                                  {
+                                  "type": "navigation"
+                                  }
+                                  ]
+                     },
+                     {
+                     "type": "stack",
+                     "meta": {
+                     "tab_config": {
+                     "title": {
+                     "key": "main_tab_title",
+                     "type": "localized_string"
+                     },
+                     "iconName": "main_tab_icon"
+                     }
+                     },
+                     "children": [
+                                  {
+                                  "type": "label"
+                                  },
+                                  {
+                                  "type": "stack",
+                                  "meta": {
+                                  "requires_navigation": "true",
+                                  "orientation": "horizontal"
+                                  }
+                                  },
+                                  {
+                                  "type": "button",
+                                  "meta": {
+                                  "title": {
+                                  "key": "start_button_title",
+                                  "type": "localized_string"
+                                  }
+                                  }
+                                  }
+                                  ]
+                     },
+                     {
+                     "type": "navigation",
+                     "children": [
+                                  {
+                                  "type": "label"
+                                  }
+                                  ]
+                     }
+                     ]
+    }
+}

Tests/Assets/invalid.json

@@ -0,0 +1,4 @@
+{
+    "structure": "test"
+    "test": "test"
+}

Tests/ComponentTests.swift

@@ -15,7 +15,7 @@ class ComponentTests: QuickSpec {
 
     override func spec() {
 
-        typealias DictMeta = Dictionary<String, String>
+        typealias DictMeta = [String: String]
 
         describe("View component") {
             it("should build a viewController") {

Tests/Helpers/JSONReader.swift

@@ -0,0 +1,42 @@
+//
+//  JSONReader.swift
+//  Matrioska
+//
+//  Created by Andreas Thenn on 12/01/2017.
+//  Copyright © 2017 runtastic. All rights reserved.
+//
+
+import Foundation
+@testable import Matrioska
+
+/// A JSONReader used to convert to JSONObject
+final class JSONReader {
+
+    /// Serializes from a given JSON Data into JSONObject
+    ///
+    /// - Parameter data: the Data object used in serialization
+    /// - Returns: an optional serialized JSONObject
+    /// - Throws: throws an error in case of failure or invalid JSON data
+    class func jsonObject(from data: Data) throws -> JSONObject? {
+        let json = try JSONSerialization.jsonObject(with: data) as? JSONObject
+
+        return json
+    }
+
+    /// Serializes from a given JSON file into JSONObject
+    ///
+    /// - Parameters:
+    ///   - jsonFilename: the file name
+    ///   - bundle: the bundle where the file is located
+    /// - Returns: an optional serialized JSONObject
+    /// - Throws: throws an error in case of failure or invalid JSON data
+    class func jsonObject(from jsonFilename: String, bundle: Bundle = .main) throws -> JSONObject? {
+        guard let filePath = bundle.path(forResource: jsonFilename, ofType: "json") else {
+            return nil
+        }
+
+        let url = URL(fileURLWithPath: filePath)
+
+        return try jsonObject(from: Data(contentsOf: url, options: .uncached))
+    }
+}