Clean up resource definition loading

Plugin/KethaneController.cs

@@ -1,51 +1,62 @@
 using System;
 using System.Collections.Generic;
+using System.Collections.ObjectModel;
 using System.Linq;
 using UnityEngine;
 
 namespace Kethane
 {
     public class KethaneController
     {
-        private static SortedDictionary<String, ResourceDefinition> resourceDefinitions = null;
+        private static IEnumerable<ResourceDefinition> resourceDefinitions = null;
 
-        public static ResourceDefinition[] ResourceDefinitions
+        public static IEnumerable<ResourceDefinition> ResourceDefinitions
         {
             get
             {
-                loadResourceDefinitions();
-                return resourceDefinitions.Values.ToArray();
+                if (resourceDefinitions == null)
+                {
+                    resourceDefinitions = loadResourceDefinitions();
+                }
+                return resourceDefinitions;
             }
         }
 
-        private static void loadResourceDefinitions()
+        private static IEnumerable<ResourceDefinition> loadResourceDefinitions()
         {
-            if (resourceDefinitions != null) { return; }
-            resourceDefinitions = new SortedDictionary<String, ResourceDefinition>();
-            foreach (var definitionNode in GameDatabase.Instance.GetConfigNodes("KethaneResource"))
+            var defs = new SortedDictionary<String, ResourceDefinition>();
+
+            foreach (var definition in GameDatabase.Instance.GetConfigNodes("KethaneResource").Select(TryLoadResourceDefinition).Where(d => d != null))
             {
-                try
+                if (!PartResourceLibrary.Instance.resourceDefinitions.Contains(definition.Resource))
                 {
-                    var definition = new ResourceDefinition(definitionNode);
-                    if (!PartResourceLibrary.Instance.resourceDefinitions.Contains(definition.Resource))
-                    {
-                        Debug.LogWarning(String.Format("[Kethane] {0} is an unknown resource, ignoring", definition.Resource));
-                    }
-                    else if (!resourceDefinitions.ContainsKey(definition.Resource))
-                    {
-                        resourceDefinitions[definition.Resource] = definition;
-                    }
-                    else
-                    {
-                        Debug.LogWarning(String.Format("[Kethane] Duplicate definition for {0}, ignoring", definition.Resource));
-                    }
+                    Debug.LogWarning(String.Format("[Kethane] {0} is an unknown resource, ignoring", definition.Resource));
                 }
-                catch (Exception e)
+                else if (defs.ContainsKey(definition.Resource))
                 {
-                    Debug.LogError(String.Format("[Kethane] Error loading resource definition:\n\n{0}", e));
+                    Debug.LogWarning(String.Format("[Kethane] Duplicate definition for {0}, ignoring", definition.Resource));
                 }
+                else
+                {
+                    defs[definition.Resource] = definition;   
+                }
+            }
+
+            Debug.Log(String.Format("[Kethane] Loaded {0} resource definitions", defs.Count));
+            return new ReadOnlyCollection<ResourceDefinition>(defs.Values.ToArray());
+        }
+
+        private static ResourceDefinition TryLoadResourceDefinition(ConfigNode node)
+        {
+            try
+            {
+                return new ResourceDefinition(node);
+            }
+            catch (Exception e)
+            {
+                Debug.LogError(String.Format("[Kethane] Error loading resource definition:\n\n{0}", e));
+                return null;
             }
-            Debug.Log(String.Format("[Kethane] Loaded {0} resource definitions", resourceDefinitions.Count));
         }
     }
 }