fix bug where loading package does not re-execute graph. (#4)

* appdomain for deps

* load engine ourselves

* review comments

* when extension is late loaded run the graph to resolve the new engine.

* test issues

DSIronPython.sln

@@ -9,6 +9,8 @@ Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "IronPythonExtension", "Iron
 EndProject
 Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "IronPythonTests", "IronPythonTests\IronPythonTests.csproj", "{E6DF2FBD-7D4D-4465-94DC-D576D737E985}"
 EndProject
+Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "DSIronPythonEmpty", "DSironPythonEmpty\DSIronPythonEmpty.csproj", "{4B853519-34A0-494D-8A16-3E79D1C5829B}"
+EndProject
 Global
 	GlobalSection(SolutionConfigurationPlatforms) = preSolution
 		Debug|Any CPU = Debug|Any CPU
@@ -27,6 +29,10 @@ Global
 		{E6DF2FBD-7D4D-4465-94DC-D576D737E985}.Debug|Any CPU.Build.0 = Debug|Any CPU
 		{E6DF2FBD-7D4D-4465-94DC-D576D737E985}.Release|Any CPU.ActiveCfg = Release|Any CPU
 		{E6DF2FBD-7D4D-4465-94DC-D576D737E985}.Release|Any CPU.Build.0 = Release|Any CPU
+		{4B853519-34A0-494D-8A16-3E79D1C5829B}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
+		{4B853519-34A0-494D-8A16-3E79D1C5829B}.Debug|Any CPU.Build.0 = Debug|Any CPU
+		{4B853519-34A0-494D-8A16-3E79D1C5829B}.Release|Any CPU.ActiveCfg = Release|Any CPU
+		{4B853519-34A0-494D-8A16-3E79D1C5829B}.Release|Any CPU.Build.0 = Release|Any CPU
 	EndGlobalSection
 	GlobalSection(SolutionProperties) = preSolution
 		HideSolutionNode = FALSE

DSIronPython/DSIronPython.csproj

@@ -29,18 +29,6 @@
 		</AssemblyAttribute>
 	</ItemGroup>
 
-	<!--<Target Name="Move python libs to extra" AfterTargets="Build">
-		<ItemGroup>
-			<MySourceFiles Include="$(OutputPath)\*lib\**;" />
-		</ItemGroup>
-
-		<Move SourceFiles="@(MySourceFiles)" DestinationFiles="$(OutputPath)..\extra\%(RecursiveDir)%(Filename)%(Extension)" />
-	</Target>
-
-	<Target Name="Remove Lib" AfterTargets="Move python libs to extra">
-		<RemoveDir Directories="$(OutputPath)\lib" />
-	</Target>-->
-
 	<Target Name="copypkgjson" AfterTargets="Build">
 		<Copy SourceFiles="pkg.json" DestinationFolder="$(OutputPath)..\"/>
 	</Target>

DSIronPython/pkg.json

@@ -15,5 +15,5 @@
     "site_url": "https://dynamobim.org/",
     "repository_url": "https://github.com/DynamoDS/Dynamo",
     "contains_binaries": true,
-    "node_libraries": []
+    "node_libraries": [ "DSIronPythonEmpty, Version=1.0.0.0, Culture=neutral, PublicKeyToken=null" ]
 }

DSironPythonEmpty/Class1.cs

@@ -0,0 +1,11 @@
+namespace DSironPythonEmpty
+{
+    /// <summary>
+    /// This class/dll exists so that Dynamo knows this package is loaded,
+    /// even though it really only contains an extension.
+    /// </summary>
+    internal class Class1
+    {
+
+    }
+}

DSironPythonEmpty/DSIronPythonEmpty.csproj

@@ -0,0 +1,12 @@
+<Project Sdk="Microsoft.NET.Sdk">
+	<ImportGroup Label="PropertySheets">
+		<Import Project="$(SolutionDir)Config\shared.props" />
+	</ImportGroup>
+  <PropertyGroup>
+	  <OutputPath>$(SolutionDir)\package_output\DSIronPython\bin\</OutputPath>
+	  <TargetFramework>net6.0</TargetFramework>
+    <ImplicitUsings>enable</ImplicitUsings>
+    <Nullable>enable</Nullable>
+  </PropertyGroup>
+
+</Project>

IronPythonExtension/IronPythonExtension.cs

@@ -1,10 +1,12 @@
-using System;
+using Dynamo.Extensions;
+using Dynamo.Graph.Workspaces;
+using Dynamo.Logging;
+using Dynamo.PythonServices;
+using System;
 using System.IO;
+using System.Linq;
 using System.Reflection;
 using System.Runtime.Loader;
-using Dynamo.Extensions;
-using Dynamo.Logging;
-using Dynamo.PythonServices;
 
 namespace IronPythonExtension
 {
@@ -59,27 +61,87 @@ public void Startup(StartupParams sp)
         /// Action to be invoked when the Dynamo has started up and is ready
         /// for user interaction. 
         /// </summary>
-        /// <param name="sp"></param>
-        public void Ready(ReadyParams sp)
+        /// <param name="rp"></param>
+        public void Ready(ReadyParams rp)
         {
-            var extraPath = Path.Combine(new FileInfo(Assembly.GetAssembly(typeof(IronPythonExtension)).Location).Directory.Parent.FullName, "extra");
-            var alc = new IsolatedPythoContext(Path.Combine(extraPath,"DSIronPython.dll"));
-            alc.LoadFromAssemblyName(new AssemblyName("DSIronPython"));
-        }
+            var extraPath = Path.Combine(new FileInfo(Assembly.GetExecutingAssembly().Location).Directory.Parent.FullName, "extra");
+            var alc = new IsolatedPythonContext(Path.Combine(extraPath,$"{PythonEvaluatorAssembly}.dll"));
+            var dsIronAssem = alc.LoadFromAssemblyName(new AssemblyName(PythonEvaluatorAssembly));
 
-        /// <summary>
-        /// Action to be invoked when shutdown has begun.
-        /// </summary>
+            //load the engine into Dynamo ourselves.
+            LoadPythonEngine(dsIronAssem);
+
+            //we used to do this:
+            //but it's not neccesary to load anything into the VM.
+            //instead we skip all the extra work and trigger the side effect we want
+            //which is re executing the graph after the dsIronPython evaluator is loaded into the PythonEngineManager.
+            //rp.StartupParams.LibraryLoader.LoadNodeLibrary(dsIronAssem);
+
+            if(rp.CurrentWorkspaceModel is HomeWorkspaceModel hwm)
+            {
+                foreach (var n in hwm.Nodes)
+                {
+                    n.MarkNodeAsModified(true);
+                }
+                hwm.Run();
+            }
+        }
         public void Shutdown()
         {
             // Do nothing for now
         }
+
+        private static void LoadPythonEngine(Assembly assembly)
+        {
+            if (assembly == null)
+            {
+                return;
+            }
+
+            // Currently we are using try-catch to validate loaded assembly and Singleton Instance method exist
+            // but we can optimize by checking all loaded types against evaluators interface later
+            try
+            {
+                Type eType = null;
+                PropertyInfo instanceProp = null;
+                try
+                {
+                    eType = assembly.GetTypes().FirstOrDefault(x => typeof(PythonEngine).IsAssignableFrom(x) && !x.IsInterface && !x.IsAbstract);
+                    if (eType == null) return;
+
+                    instanceProp = eType?.GetProperty("Instance", BindingFlags.NonPublic | BindingFlags.Static);
+                    if (instanceProp == null) return;
+                }
+                catch
+                {
+                    // Ignore exceptions from iterating assembly types.
+                    return;
+                }
+
+                PythonEngine engine = (PythonEngine)instanceProp.GetValue(null);
+                if (engine == null)
+                {
+                    throw new Exception($"Could not get a valid PythonEngine instance by calling the {eType.Name}.Instance method");
+                }
+
+                if (PythonEngineManager.Instance.AvailableEngines.All(x => x.Name != engine.Name))
+                {
+                    PythonEngineManager.Instance.AvailableEngines.Add(engine);
+                }
+            }
+            catch (Exception ex)
+            {
+                throw new Exception($"Failed to add a Python engine from assembly {assembly.GetName().Name}.dll with error: {ex.Message}");
+            }
+        }
+
+
     }
-    internal class IsolatedPythoContext : AssemblyLoadContext
+    internal class IsolatedPythonContext : AssemblyLoadContext
     {
         private AssemblyDependencyResolver resolver;
 
-        public IsolatedPythoContext(string libPath)
+        public IsolatedPythonContext(string libPath)
         {
             resolver = new AssemblyDependencyResolver(libPath);
         }