Add version information to serialized asset classes (#90)

Assets/Mapzen/Unity/MapStyle.cs

@@ -8,14 +8,26 @@ namespace Mapzen.Unity
     [CreateAssetMenu(menuName = "Mapzen/MapStyle")]
     public class MapStyle : ScriptableObject
     {
-        public List<FeatureLayer> Layers;
+        // Version information
+        // This allows us to check whether an asset was serialized with a different version than this code.
+        // If a serialized field of this class is changed or renamed, currentAssetVersion should be incremented.
+
+        private const int currentAssetVersion = 1;
+        [SerializeField] private int serializedAssetVersion = currentAssetVersion;
+
+        public List<FeatureLayer> Layers = new List<FeatureLayer>();
 
         [SerializeField]
         private bool liveUpdateEnabled;
 
-        public MapStyle()
+        void OnEnable()
         {
-            this.Layers = new List<FeatureLayer>();
+            if (serializedAssetVersion != currentAssetVersion)
+            {
+                Debug.LogWarningFormat("The MapStyle \"{0}\" was created with a different version of this tool. " +
+                    "Some properties may be missing or have unexpected values.", this.name);
+                serializedAssetVersion = currentAssetVersion;
+            }
         }
     }
 }

Assets/RegionMap.cs

@@ -10,6 +10,13 @@ namespace Mapzen
 {
     public class RegionMap : MonoBehaviour
     {
+        // Version information
+        // This allows us to check whether an asset was serialized with a different version than this code.
+        // If a serialized field of this class is changed or renamed, currentAssetVersion should be incremented.
+
+        private const int currentAssetVersion = 1;
+        [SerializeField] private int serializedAssetVersion = currentAssetVersion;
+
         // Public fields
         // These are serialized, so renaming them will break asset compatibility.
 
@@ -224,5 +231,15 @@ public void LogErrors()
                 Debug.LogError("Make sure to set a MapStyle");
             }
         }
+
+        public void OnValidate()
+        {
+            if (serializedAssetVersion != currentAssetVersion)
+            {
+                Debug.LogWarningFormat("The RegionMap \"{0}\" was created with a different version of this tool. " +
+                    "Some properties may be missing or have unexpected values.", this.name);
+                serializedAssetVersion = currentAssetVersion;
+            }
+        }
     }
 }

Assets/Scenes/DefaultScene.unity

@@ -135,6 +135,7 @@ MonoBehaviour:
   m_Script: {fileID: 11500000, guid: 673da631ad95c423cbdabfdc9202e581, type: 3}
   m_Name: 
   m_EditorClassIdentifier: 
+  serializedAssetVersion: 1
   ApiKey: 
   Area:
     min:

Assets/Scenes/SimpleMapStyle.asset

@@ -11,6 +11,7 @@ MonoBehaviour:
   m_Script: {fileID: 11500000, guid: a4edcc12ded754f86bc8b9ea3b3c3ee6, type: 3}
   m_Name: SimpleMapStyle
   m_EditorClassIdentifier: 
+  serializedAssetVersion: 1
   Layers:
   - Name: Water
     FeatureCollection: 256
@@ -116,3 +117,4 @@ MonoBehaviour:
         Width: 0
         MiterLimit: 0
         Enabled: 0
+  liveUpdateEnabled: 0