refactor: Rewrite Loader in C#

dev/Directory.Build.props

@@ -2,8 +2,6 @@
 <Project ToolsVersion="15.0" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
   <PropertyGroup>
     <OutputType>Library</OutputType>
-<!--    <TargetFramework>net48</TargetFramework>-->
-<!--    <TargetFrameworks>net48;net8.0-windows</TargetFrameworks>-->
     <PlatformTarget>x64</PlatformTarget>
     <CopyLocalLockFileAssemblies>true</CopyLocalLockFileAssemblies>
   </PropertyGroup>

dev/pyRevitLabs.PyRevit.Runtime/ScriptCommands.cs

@@ -273,10 +273,16 @@ public Result Execute(ExternalCommandData commandData, ref string message, Eleme
 
             // 3: ----------------------------------------------------------------------------------------------------
             #region Execute and log results
+
             // Executing the script and logging the results
-            // Get script executor and Execute the script
             var env = new EnvDictionary();
-            int result = ScriptExecutor.ExecuteScript(
+            int result = -1;
+
+            // Initialize ScriptExecutor before executing scripts
+            ScriptExecutor.Initialize();
+
+            // Execute the script
+            result = ScriptExecutor.ExecuteScript(
                 ScriptData,
                 ScriptRuntimeConfigs,
                 new ScriptExecutorConfigs {

dev/pyRevitLabs/pyRevitLabs.PyRevit/PyRevitConsts.cs

@@ -176,6 +176,12 @@ public static class PyRevitConsts {
         public const string BundleScriptGrasshopperXPostfix = ".ghx";
         public const string BundleScriptRevitFamilyPostfix = ".rfa";
 
+        // loader settings
+        public const string ConfigsNewLoaderKey = "new_loader";
+        public const bool ConfigsNewLoaderDefault = false;
+        public const string ConfigsUseRoslynKey = "use_roslyn_loader";
+        public const bool ConfigsUseRoslynDefault = false;
+
         // theme
         public static SolidColorBrush PyRevitAccentBrush = new SolidColorBrush(Color.FromArgb(0xFF, 0xf3, 0x9c, 0x12));
         public static SolidColorBrush PyRevitBackgroundBrush = new SolidColorBrush(Color.FromArgb(0xFF, 0x2c, 0x3e, 0x50));

dev/pyRevitLoader/Directory.Build.props

@@ -1,11 +1,11 @@
 <?xml version="1.0" encoding="UTF-8"?>
 <Project ToolsVersion="15.0" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
-    <PropertyGroup>
+    <PropertyGroup Condition="'$(MSBuildProjectName)' != 'pyRevitAssemblyBuilder'">
         <UseRevit>true</UseRevit>
         <UseWpf>true</UseWpf>
         <UseWindowsForms>true</UseWindowsForms>
+        <UseAssemblyBuilder Condition="'$(MSBuildProjectName)' != 'pyRevitLoader.2712PR' AND '$(MSBuildProjectName)' != 'pyRevitLoader.342'">true</UseAssemblyBuilder>
         <TargetFrameworks>net48;net8.0-windows</TargetFrameworks>
-
         <EnableDefaultCompileItems>false</EnableDefaultCompileItems>
     </PropertyGroup>
 

dev/pyRevitLoader/Directory.Build.targets

@@ -6,7 +6,7 @@
         <None Remove="obj\**" />
     </ItemGroup>
 
-    <ItemGroup Condition="$(UseRunner)=='' OR $(UseRunner)==False">
+    <ItemGroup Condition="$(UseLoader)==True">
         <Compile Include="..\Source\PyRevitLoaderApplication.cs" Link="Source\PyRevitLoaderApplication.cs"/>
         <Compile Include="..\Source\ScriptExecutor.cs" Link="Source\ScriptExecutor.cs"/>
     </ItemGroup>
@@ -17,7 +17,7 @@
         <Compile Include="..\Source\ScriptExecutor.cs" Link="Source\ScriptExecutor.cs"/>
     </ItemGroup>
 
-    <ItemGroup Condition="$(IronPythonVersion.Contains('PR'))">
+    <ItemGroup Condition="'$(UseIronPython)' != 'false' AND $(IronPythonVersion.Contains('PR'))">
         <Reference Include="IronPython" HintPath="$(PyRevitEnginesDir)\$(IronPythonVersion)\pyRevitLabs.IronPython.dll"/>
         <Reference Include="IronPython.Modules" HintPath="$(PyRevitEnginesDir)\$(IronPythonVersion)\pyRevitLabs.IronPython.Modules.dll"/>
         <Reference Include="IronPython.SQLite" HintPath="$(PyRevitEnginesDir)\$(IronPythonVersion)\pyRevitLabs.IronPython.SQLite.dll"/>
@@ -26,27 +26,67 @@
         <Reference Include="Microsoft.Scripting" HintPath="$(PyRevitEnginesDir)\$(IronPythonVersion)\pyRevitLabs.Microsoft.Scripting.dll"/>
     </ItemGroup>
 
-    <ItemGroup Condition="!$(IronPythonVersion.Contains('PR'))">
+    <ItemGroup Condition="'$(UseIronPython)' != 'false' AND !$(IronPythonVersion.Contains('PR'))">
         <PackageReference Include="IronPython" Version="$(Version)"/>
     </ItemGroup>
 
     <ItemGroup>
         <Reference Condition="'$(TargetFrameworkIdentifier)' == '.NETFramework'" Include="Microsoft.CSharp"/>
     </ItemGroup>
-
-    <ItemGroup>
+
+    <ItemGroup Condition="'$(UseAssemblyBuilder)' == 'true'">
+        <ProjectReference Include="..\pyRevitAssemblyBuilder\pyRevitAssemblyBuilder.csproj" />
+    </ItemGroup>
+
+    <ItemGroup Condition="'$(UseExtensionParser)' == 'true'">
+        <ProjectReference Include="..\pyRevitExtensionParser\pyRevitExtensionParser.csproj" />
+    </ItemGroup>
+
+    <ItemGroup Condition="'$(UseIronPython)' != 'false'">
         <EmbeddedResource Include="$(IronPythonStdLibDir)\$(IronPythonStdLib)"/>
     </ItemGroup>
-
+
+    <ItemGroup Condition="'$(UseRoslyn)' == 'true'">
+        <PackageReference Include="Microsoft.CodeAnalysis.CSharp" Version="4.13.0" />
+    </ItemGroup>
+
+    <ItemGroup Condition="'$(UseILPack)' == 'true'">
+        <PackageReference Include="Lokad.ILPack" Version="0.3.0" ExcludeAssets="runtime" />
+    </ItemGroup>
+
     <Target Name="Deploy" AfterTargets="AfterBuild">
         <ItemGroup>
             <AllFilesToCopy Include="$(TargetDir)\**\*.dll"
-                            Exclude="$(TargetDir)\**\Xceed.Wpf.AvalonDock.dll" />
+                            Exclude="$(TargetDir)\**\Xceed.Wpf.AvalonDock.dll;
+                                     $(TargetDir)\**\Microsoft.CodeAnalysis.dll;
+                                     $(TargetDir)\**\Microsoft.CodeAnalysis.CSharp.dll;
+                                     $(TargetDir)\**\Microsoft.CodeAnalysis.CSharp.resources.dll;
+                                     $(TargetDir)\**\Microsoft.CodeAnalysis.resources.dll;
+                                     $(TargetDir)\**\System.*.dll"
+                            Condition="'$(IsTestProject)' != 'true'"/>
         </ItemGroup>
+
+        <!-- Default deployment to single version -->
+        <Copy SourceFiles="@(AllFilesToCopy)" 
+                DestinationFolder="$(PyRevitEnginesDir)\$(IronPythonVersion)" 
+                Condition="'$(DeployToAllVersions)' != 'true'" />
+        <Message Importance="high" 
+                Text="$(MSBuildProjectName) -> Copy to $([System.IO.Path]::GetFullPath('$(PyRevitEnginesDir)\$(IronPythonVersion)'))"
+                Condition="'$(DeployToAllVersions)' != 'true'" />
+
+        <!-- Multi-version deployment for shared components -->
+        <Copy SourceFiles="@(AllFilesToCopy)" 
+                DestinationFolder="$(PyRevitEnginesDir)\IPY342" 
+                Condition="'$(DeployToAllVersions)' == 'true'" />
+        <Message Importance="high" 
+                Text="$(MSBuildProjectName) -> Copy to $([System.IO.Path]::GetFullPath('$(PyRevitEnginesDir)\IPY342'))"
+                Condition="'$(DeployToAllVersions)' == 'true'" />
         <Copy SourceFiles="@(AllFilesToCopy)" 
-                DestinationFolder="$(PyRevitEnginesDir)\$(IronPythonVersion)" />
+                DestinationFolder="$(PyRevitEnginesDir)\IPY2712PR" 
+                Condition="'$(DeployToAllVersions)' == 'true'" />
         <Message Importance="high" 
-                Text="$(MSBuildProjectName) -> Copy to $([System.IO.Path]::GetFullPath('$(PyRevitEnginesDir)\$(IronPythonVersion)'))" />
+                Text="$(MSBuildProjectName) -> Copy to $([System.IO.Path]::GetFullPath('$(PyRevitEnginesDir)\IPY2712PR'))"
+                Condition="'$(DeployToAllVersions)' == 'true'" />
     </Target>
 
 </Project>

dev/pyRevitLoader/Source/PyRevitLoaderApplication.cs

@@ -1,8 +1,12 @@
 using System;
 using System.IO;
 using System.Reflection;
+using System.Diagnostics;
 using Autodesk.Revit.UI;
 using Autodesk.Revit.Attributes;
+using pyRevitAssemblyBuilder.AssemblyMaker;
+using pyRevitAssemblyBuilder.SessionManager;
+using pyRevitExtensionParser;
 
 /* Note:
  * It is necessary that this code object do not have any references to IronPython.
@@ -17,18 +21,38 @@ namespace PyRevitLoader
     class PyRevitLoaderApplication : IExternalApplication
     {
         public static string LoaderPath => Path.GetDirectoryName(typeof(PyRevitLoaderApplication).Assembly.Location);
+
+        // Store the UIControlledApplication for later use
+        private static UIControlledApplication _uiControlledApplication;
 
         // Hook into Revit to allow starting a command.
         Result IExternalApplication.OnStartup(UIControlledApplication application)
         {
+            // Store the UIControlledApplication for later use
+            _uiControlledApplication = application;
+
             LoadAssembliesInFolder(LoaderPath);
             // We need to also looad dlls from two folders up
             var commonFolder = Path.GetDirectoryName(Path.GetDirectoryName(LoaderPath));
             LoadAssembliesInFolder(commonFolder);
 
             try
             {
-                return ExecuteStartupScript(application);
+                // we need a UIApplication object to assign as `__revit__` in python...
+                var versionNumber = application.ControlledApplication.VersionNumber;
+                var fieldName = int.Parse(versionNumber) >= 2017 ? "m_uiapplication" : "m_application";
+                var fi = application.GetType().GetField(fieldName, BindingFlags.NonPublic | BindingFlags.Instance);
+
+                var uiApplication = (UIApplication)fi.GetValue(application);
+
+                var executor = new ScriptExecutor(uiApplication);
+                var result = ExecuteStartupScript(application);
+                if (result == Result.Failed)
+                {
+                    TaskDialog.Show("Error Loading pyRevit", executor.Message);
+                }
+
+                return result;
             }
             catch (Exception ex)
             {
@@ -47,13 +71,23 @@ private static void LoadAssembliesInFolder(string folder)
                 {
                     Assembly.LoadFrom(engineDll);
                 }
-                catch
+                catch (Exception ex)
                 {
+                    // Log assembly load failures - some assemblies may fail to load and that's acceptable
+                    Trace.WriteLine($"Failed to load assembly '{engineDll}': {ex.Message}");
                 }
             }
         }
 
         private static Result ExecuteStartupScript(UIControlledApplication uiControlledApplication)
+        {
+            // Always execute Python startup script
+            // The Python script will determine whether to use C# or Python session management
+            // based on the configuration
+            return ExecuteStartUpPython(uiControlledApplication);
+        }
+
+        public static Result ExecuteStartUpPython(UIControlledApplication uiControlledApplication)
         {
             // we need a UIApplication object to assign as `__revit__` in python...
             var versionNumber = uiControlledApplication.ControlledApplication.VersionNumber;
@@ -66,28 +100,124 @@ private static Result ExecuteStartupScript(UIControlledApplication uiControlledA
             var startupScript = GetStartupScriptPath();
             if (startupScript != null)
             {
-                var executor = new ScriptExecutor(uiApplication); // uiControlledApplication);
-                result = executor.ExecuteScript(startupScript);
-                if (result == Result.Failed)
+                var versionNumber = uiControlledApplication.ControlledApplication.VersionNumber;
+                var fieldName = int.Parse(versionNumber) >= 2017 ? "m_uiapplication" : "m_application";
+                var fi = uiControlledApplication.GetType().GetField(fieldName, BindingFlags.NonPublic | BindingFlags.Instance);
+                var uiApplication = (UIApplication)fi.GetValue(uiControlledApplication);
+
+                // Instantiate all services
+                var typeGenerator = new CommandTypeGenerator();
+                var assemblyBuilder = new AssemblyBuilderService(typeGenerator, versionNumber);
+                var extensionManager = new ExtensionManagerService();
+                var hookManager = new HookManager();
+                var uiManager = new UIManagerService(uiApplication);
+
+                var sessionManager = new SessionManagerService(
+                    assemblyBuilder,
+                    extensionManager,
+                    hookManager,
+                    uiManager
+                );
+
+                sessionManager.LoadSession();
+
+                // execute light version of StartupScript python script  
+                Result result = Result.Succeeded;
+                var startupScript = GetStartupScriptPath(true);
+                if (startupScript != null)
                 {
-                    TaskDialog.Show("Error Loading pyRevit", executor.Message);
+                    var executor = new ScriptExecutor(uiApplication); // uiControlledApplication);
+                    result = executor.ExecuteScript(startupScript);
+                    if (result == Result.Failed)
+                    {
+                        TaskDialog.Show("Error Loading pyRevit", executor.Message);
+                    }
                 }
-            }
 
             return result;
         }
 
+        public static Result LoadSession(object pythonLogger = null, string buildStrategy = null)
+        {
+            try
+            {
+                // Use the stored UIControlledApplication
+                if (_uiControlledApplication == null)
+                {
+                    throw new InvalidOperationException("UIControlledApplication not available. LoadSession can only be called after OnStartup.");
+                }
+
+                var uiControlledApplication = _uiControlledApplication;
+                // we need a UIApplication object to assign as `__revit__` in python...
+                var versionNumber = uiControlledApplication.ControlledApplication.VersionNumber;
+                var fieldName = int.Parse(versionNumber) >= 2017 ? "m_uiapplication" : "m_application";
+                var fi = uiControlledApplication.GetType().GetField(fieldName, BindingFlags.NonPublic | BindingFlags.Instance);
+
+                var uiApplication = (UIApplication)fi.GetValue(uiControlledApplication);
+
+                // Get the current Revit version
+                var revitVersion = uiControlledApplication.ControlledApplication.VersionNumber;
+
+                // Determine build strategy: use provided parameter, or read from config, or default to ILPack
+                var assemblyBuildStrategyType = typeof(pyRevitAssemblyBuilder.AssemblyMaker.AssemblyBuildStrategy);
+                object strategyValue;
+
+                if (!string.IsNullOrEmpty(buildStrategy))
+                {
+                    // Use provided build strategy from Python
+                    strategyValue = Enum.Parse(assemblyBuildStrategyType, buildStrategy);
+                }
+                else
+                {
+                    // Fallback: read from config
+                    try
+                    {
+                        var config = PyRevitConfig.Load();
+                        var strategyName = config.NewLoaderRoslyn ? "Roslyn" : "ILPack";
+                        strategyValue = Enum.Parse(assemblyBuildStrategyType, strategyName);
+                    }
+                    catch
+                    {
+                        // Final fallback: default to ILPack
+                        strategyValue = Enum.Parse(assemblyBuildStrategyType, "ILPack");
+                    }
+                }
+
+                // Create services using factory
+                var strategyEnum = (pyRevitAssemblyBuilder.AssemblyMaker.AssemblyBuildStrategy)strategyValue;
+                var sessionManager = pyRevitAssemblyBuilder.SessionManager.ServiceFactory.CreateSessionManagerService(
+                    revitVersion,
+                    strategyEnum,
+                    uiApplication,
+                    pythonLogger);
+
+                // Load the session using the C# SessionManagerService
+                sessionManager.LoadSession();
+
+                return Result.Succeeded;
+            }
+            catch (Exception ex)
+            {
+                // Log detailed error information before showing dialog
+                Trace.WriteLine($"Error Loading C# Session: {ex}");
+                Trace.WriteLine($"Stack Trace: {ex.StackTrace}");
+
+                // Show user-friendly error dialog
+                TaskDialog.Show("Error Loading C# Session", 
+                    $"An error occurred while loading the C# session:\n\n{ex.Message}\n\nCheck the output window for details.");
+                return Result.Failed;
+            }
+        }
         private static string GetStartupScriptPath()
         {
             var loaderDir = Path.GetDirectoryName(Assembly.GetExecutingAssembly().Location);
             var dllDir = Path.GetDirectoryName(loaderDir);
             return Path.Combine(dllDir, string.Format("{0}.py", Assembly.GetExecutingAssembly().GetName().Name));
         }
-
         Result IExternalApplication.OnShutdown(UIControlledApplication application)
         {
             // FIXME: deallocate the python shell...
             return Result.Succeeded;
         }
     }
-}
+}