From 943845a8efffa5c417ad0d28c493e83bbb825b87 Mon Sep 17 00:00:00 2001
From: stephenriolo <riolo.stephen@gmail.com>
Date: Wed, 19 Oct 2016 12:44:22 +0200
Subject: [PATCH] - Added handling of aliases in style.json

---
 StyleKit/Stylist.swift                     | 40 +++++++++++++++++++---
 StyleKitDemo/StyleKitDemo/Style/style.json | 14 +++++---
 2 files changed, 45 insertions(+), 9 deletions(-)

diff --git a/StyleKit/Stylist.swift b/StyleKit/Stylist.swift
index b3559a0..aa6b331 100644
--- a/StyleKit/Stylist.swift
+++ b/StyleKit/Stylist.swift
@@ -6,13 +6,27 @@ class Stylist {
     typealias setValueForControlState = @convention(c) (AnyObject, Selector, AnyObject, UInt) -> Void
     
     let data: Style
+    let aliases: Style
     let styleParser: StyleParsable
     var currentComponent: AnyClass?
     var viewStack = [UIAppearanceContainer.Type]()
     
     init(data: Style, styleParser: StyleParsable?) {
         self.styleParser = styleParser ?? StyleParser()
-        self.data = data
+        
+        var tmpAlias: Style = [:]
+        var tmpData: Style = [:]
+        
+        for (key, value) in data {
+            if key.hasPrefix("@") {
+                tmpAlias[key] = value
+            } else {
+                tmpData[key] = value
+            }
+        }
+        
+        self.data = tmpData
+        self.aliases = tmpAlias
     }
     
     func apply() {
@@ -78,14 +92,33 @@ class Stylist {
         if let styles = object as? Stylist.Style {
             var stylesToApply = Stylist.Style()
             for (style, value) in styles {
-                stylesToApply[style] = styleParser.getStyle(forName: name, value: value)
+                stylesToApply[style] = styleParser.getStyle(forName: name, value: self.getValue(value))
             }
             callAppearanceSelector(selectorName, valueOne: stylesToApply as AnyObject?, valueTwo: state)
         } else {
-            let value = styleParser.getStyle(forName: name, value: object)
+            let value = styleParser.getStyle(forName: name, value: self.getValue(object))
             callAppearanceSelector(selectorName, valueOne: value, valueTwo: state)
         }
+    }
+
+    /**
+        Checks if the value is an alias, and if it is resolves to the correct value. 
+        Otherwise, it will return the passed value.
+     
+        - Parameter value: The alias name or actual value
+    */
+    private func getValue(_ value: AnyObject) -> AnyObject {
+        guard value is String, value.hasPrefix("@") else {
+            return value
+        }
         
+        if let aliasValue = aliases[value as! String] {
+            return aliasValue
+        } else {
+            SKLogger.error("Value declared is using Alias \(value) which has not been defined")
+            
+            return value
+        }
     }
     
     private func callAppearanceSelector(_ selector: String, valueOne: AnyObject?, valueTwo: AnyObject?) {
@@ -136,5 +169,4 @@ class Stylist {
             }
         }
     }
-    
 }
diff --git a/StyleKitDemo/StyleKitDemo/Style/style.json b/StyleKitDemo/StyleKitDemo/Style/style.json
index e78d1bb..6f0292c 100644
--- a/StyleKitDemo/StyleKitDemo/Style/style.json
+++ b/StyleKitDemo/StyleKitDemo/Style/style.json
@@ -1,9 +1,13 @@
 {
+    "@mainFont": "HelveticaNeue-Bold:20.0",
+    "@primaryColor": "#000000",
+    "@secondaryColor": "#000FFF",
+    "@transperancyValue": 90,
     "StyleKitDemo.SKNavigationBar": {
-        "tintColor": "#000",
+        "tintColor": "@secondaryColor",
         "titleTextAttributes": {
             "NSColor": "#99000000",
-            "NSFont": "HelveticaNeue-Light:18.0"
+            "NSFont": "@mainFont"
         }
     },
     "UITableView": {
@@ -21,12 +25,12 @@
         }
     },
     "StyleKitDemo.SKButton": {
-        "backgroundColor:normal": "#cd0073",
+        "backgroundColor:normal": "@primaryColor",
         "backgroundColor:highlighted": "#8000c6",
         "titleColor:normal": "#fff",
         "titleColor:highlighted": "#fff",
         "font": "HelveticaNeue-Light:13.0",
-        "transparency":70
+        "transparency":"@transperancyValue"
     },
     "UIButton": {
         "font": "HelveticaNeue-Medium:13.0",
@@ -83,4 +87,4 @@
     "UIActivityIndicatorView": {
         "color": "#cd0073"
     }
-}
\ No newline at end of file
+}