From 92b757edc37d8ebc5aeaa4b64e98b1299618a920 Mon Sep 17 00:00:00 2001
From: Michael Becker <alcexhim@gmail.com>
Date: Sat, 21 Dec 2024 00:21:14 -0500
Subject: [PATCH] add convenience function for derived instances so we don't
 have to allocate an InstanceHandle

---
 mocha-dotnet/src/lib/Mocha.Core/Oms.cs         | 18 ++++++++++++++++++
 .../Mocha.Core.Tests/DerivedInstanceTests.cs   |  2 +-
 2 files changed, 19 insertions(+), 1 deletion(-)

diff --git a/mocha-dotnet/src/lib/Mocha.Core/Oms.cs b/mocha-dotnet/src/lib/Mocha.Core/Oms.cs
index da9156d..e1edfa4 100644
--- a/mocha-dotnet/src/lib/Mocha.Core/Oms.cs
+++ b/mocha-dotnet/src/lib/Mocha.Core/Oms.cs
@@ -654,6 +654,24 @@ public abstract class Oms
 		return false;
     }
 
+	public T GetAttributeValue<T>(InstanceKey source, InstanceHandle attribute, T defaultValue = default(T), DateTime? effectiveDate = null)
+	{
+		if (source.IsDerived)
+		{
+			source._oms = this;
+			Dictionary<InstanceHandle, object?> derivedData = source.GetDerivedData();
+			if (derivedData.ContainsKey(attribute))
+			{
+				return (T) derivedData[attribute];
+			}
+			return defaultValue;
+		}
+		else
+		{
+			InstanceHandle hSource = GetInstance(source);
+			return GetAttributeValue<T>(hSource, attribute, defaultValue, effectiveDate);
+		}
+	}
     public T GetAttributeValue<T>(InstanceHandle source, InstanceHandle attribute, T defaultValue = default(T), DateTime? effectiveDate = null)
 	{
 		Dictionary<InstanceHandle, object>? derivedData = GetDerivedData(source);
diff --git a/mocha-dotnet/tests/Mocha.Core.Tests/DerivedInstanceTests.cs b/mocha-dotnet/tests/Mocha.Core.Tests/DerivedInstanceTests.cs
index 0455344..d38b49f 100644
--- a/mocha-dotnet/tests/Mocha.Core.Tests/DerivedInstanceTests.cs
+++ b/mocha-dotnet/tests/Mocha.Core.Tests/DerivedInstanceTests.cs
@@ -47,7 +47,7 @@ public class DerivedInstanceTests : OmsTestsBase
 
 		InstanceHandle ih = Oms.GetInstance(ik);
 		
-		string attVName = Oms.GetAttributeValue<string>(ih, Oms.GetInstance(KnownAttributeGuids.Text.Name));
+		string attVName = Oms.GetAttributeValue<string>(ik, Oms.GetInstance(KnownAttributeGuids.Text.Name));
 		Assert.That(attVName, Is.EqualTo(TEST_DERIVED_VALUE));
 	}