Merge branch 'develop' into stable

2 files changed, 57 insertions, 7 deletions

diff --git a/src/StardewModdingAPI/Framework/Reflection/CacheEntry.cs b/src/StardewModdingAPI/Framework/Reflection/CacheEntry.cs
new file mode 100644
index 00000000..30faca37
--- /dev/null
+++ b/src/StardewModdingAPI/Framework/Reflection/CacheEntry.cs
@@ -0,0 +1,30 @@
+using System.Reflection;
+
+namespace StardewModdingAPI.Framework.Reflection
+{
+    /// <summary>A cached member reflection result.</summary>
+    internal struct CacheEntry
+    {
+        /*********
+        ** Accessors
+        *********/
+        /// <summary>Whether the lookup found a valid match.</summary>
+        public bool IsValid;
+
+        /// <summary>The reflection data for this member (or <c>null</c> if invalid).</summary>
+        public MemberInfo MemberInfo;
+
+
+        /*********
+        ** Public methods
+        *********/
+        /// <summary>Construct an instance.</summary>
+        /// <param name="isValid">Whether the lookup found a valid match.</param>
+        /// <param name="memberInfo">The reflection data for this member (or <c>null</c> if invalid).</param>
+        public CacheEntry(bool isValid, MemberInfo memberInfo)
+        {
+            this.IsValid = isValid;
+            this.MemberInfo = memberInfo;
+        }
+    }
+}
diff --git a/src/StardewModdingAPI/Framework/Reflection/ReflectionHelper.cs b/src/StardewModdingAPI/Framework/Reflection/ReflectionHelper.cs
index 38b4e357..edf59b81 100644
--- a/src/StardewModdingAPI/Framework/Reflection/ReflectionHelper.cs
+++ b/src/StardewModdingAPI/Framework/Reflection/ReflectionHelper.cs
@@ -67,10 +67,17 @@ namespace StardewModdingAPI.Framework.Reflection
         /// <param name="obj">The object which has the field.</param>
         /// <param name="name">The field name.</param>
         /// <param name="required">Whether to throw an exception if the private field is not found.</param>
-        /// <remarks>This is a shortcut for <see cref="GetPrivateField{TValue}(object,string,bool)"/> followed by <see cref="IPrivateField{TValue}.GetValue"/>.</remarks>
+        /// <returns>Returns the field value, or the default value for <typeparamref name="TValue"/> if the field wasn't found and <paramref name="required"/> is false.</returns>
+        /// <remarks>
+        /// This is a shortcut for <see cref="GetPrivateField{TValue}(object,string,bool)"/> followed by <see cref="IPrivateField{TValue}.GetValue"/>.
+        /// When <paramref name="required" /> is false, this will return the default value if reflection fails. If you need to check whether the field exists, use <see cref="GetPrivateField{TValue}(object,string,bool)" /> instead.
+        /// </remarks>
         public TValue GetPrivateValue<TValue>(object obj, string name, bool required = true)
         {
-            return this.GetPrivateField<TValue>(obj, name, required).GetValue();
+            IPrivateField<TValue> field = this.GetPrivateField<TValue>(obj, name, required);
+            return field != null
+                ? field.GetValue()
+                : default(TValue);
         }
 
         /// <summary>Get the value of a private static field.</summary>
@@ -78,10 +85,17 @@ namespace StardewModdingAPI.Framework.Reflection
         /// <param name="type">The type which has the field.</param>
         /// <param name="name">The field name.</param>
         /// <param name="required">Whether to throw an exception if the private field is not found.</param>
-        /// <remarks>This is a shortcut for <see cref="GetPrivateField{TValue}(Type,string,bool)"/> followed by <see cref="IPrivateField{TValue}.GetValue"/>.</remarks>
+        /// <returns>Returns the field value, or the default value for <typeparamref name="TValue"/> if the field wasn't found and <paramref name="required"/> is false.</returns>
+        /// <remarks>
+        /// This is a shortcut for <see cref="GetPrivateField{TValue}(Type,string,bool)"/> followed by <see cref="IPrivateField{TValue}.GetValue"/>.
+        /// When <paramref name="required" /> is false, this will return the default value if reflection fails. If you need to check whether the field exists, use <see cref="GetPrivateField{TValue}(Type,string,bool)" /> instead.
+        /// </remarks>
         public TValue GetPrivateValue<TValue>(Type type, string name, bool required = true)
         {
-            return this.GetPrivateField<TValue>(type, name, required).GetValue();
+            IPrivateField<TValue> field = this.GetPrivateField<TValue>(type, name, required);
+            return field != null
+                ? field.GetValue()
+                : default(TValue);
         }
 
         /****
@@ -228,12 +242,18 @@ namespace StardewModdingAPI.Framework.Reflection
         {
             // get from cache
             if (this.Cache.Contains(key))
-                return (TMemberInfo)this.Cache[key];
+            {
+                CacheEntry entry = (CacheEntry)this.Cache[key];
+                return entry.IsValid
+                    ? (TMemberInfo)entry.MemberInfo
+                    : default(TMemberInfo);
+            }
 
             // fetch & cache new value
             TMemberInfo result = fetch();
-            this.Cache.Add(key, result, new CacheItemPolicy { SlidingExpiration = this.SlidingCacheExpiry });
+            CacheEntry cacheEntry = new CacheEntry(result != null, result);
+            this.Cache.Add(key, cacheEntry, new CacheItemPolicy { SlidingExpiration = this.SlidingCacheExpiry });
             return result;
         }
     }
-}
\ No newline at end of file
+}