Merge pull request #1 from rchande/MEFfix

Make MEF work

src/OmniSharp.Abstractions/Mef/ExportIProjectSystemAttribute.cs

@@ -1,18 +1,27 @@
 using OmniSharp.Services;
 using System;
-using System.ComponentModel.Composition;
+using System.Composition;
 
 namespace OmniSharp.Mef
 {
     [MetadataAttribute]
     [AttributeUsage(AttributeTargets.Class, AllowMultiple = false)]
     public class ExportIProjectSystemAttribute: ExportAttribute
     {
-        public string Name;
+        public string Name { get; }
+        public string Before { get; }
+        public string After { get; }
 
-        public ExportIProjectSystemAttribute(string name) : base(name, typeof(IProjectSystem))
+        public ExportIProjectSystemAttribute(string name, string before="", string after="") : base(typeof(IProjectSystem))
         {
             Name = name;
+            Before = before;
+            After = after;
         }
     }
+
+    public class ProjectSystemMetadata 
+    {
+         string Name { get; set; }
+    }
 }

src/OmniSharp.Abstractions/Mef/IOrderableMetadata.cs

@@ -0,0 +1,26 @@
+using System;
+using System.Collections.Generic;
+using System.ComponentModel;
+using System.Linq;
+using System.Text;
+using System.Threading.Tasks;
+
+namespace OmniSharp.Mef
+{
+    internal interface IOrderableMetadata
+    {
+        [DefaultValue("")]
+        string After { get; }
+        [DefaultValue("")]
+        string Before { get; }
+        string Name { get; }
+    }
+
+    class OrderableMetadata
+    {
+        public string After { get; set; }
+
+        public string Before { get; set; }
+        public string Name { get; set; }
+    }
+}

src/OmniSharp.Host/WorkspaceInitializer.cs

@@ -3,10 +3,12 @@
 using System.ComponentModel;
 using System.Composition;
 using System.Composition.Hosting;
+using System.Linq;
 using Microsoft.Extensions.Configuration;
 using Microsoft.Extensions.DependencyInjection;
 using Microsoft.Extensions.Logging;
 using Microsoft.Extensions.Options;
+using OmniSharp.Mef;
 using OmniSharp.Options;
 using OmniSharp.Roslyn;
 using OmniSharp.Roslyn.Options;
@@ -28,8 +30,10 @@ public static void Initialize(
 
             var projectEventForwarder = compositionHost.GetExport<ProjectEventForwarder>();
             projectEventForwarder.Initialize();
-            var projectSystems = compositionHost.GetExports<IProjectSystem>();
-            var orderedProjectSystems = ExtensionOrderer.GetOrderedOrUnorderedList<IProjectSystem, Attribute>(projectSystems, _=> null);
+            var projectSystems = compositionHost.GetExports<Lazy<IProjectSystem, OrderableMetadata>>();
+            var ps = projectSystems.Select(n => n.Value);
+            var qs = projectSystems.Select(n => n.Metadata);
+            var orderedProjectSystems = ExtensionOrderer.GetOrderedOrUnorderedList<IProjectSystem, ExportIProjectSystemAttribute>(ps, eps => eps.Name);
 
             foreach (var projectSystem in orderedProjectSystems)
             {

src/OmniSharp.MiscellanousFiles/MiscellanousFiles.cs

@@ -17,8 +17,8 @@
 
 namespace OmniSharp.MiscellanousFiles
 {
-    [ExtensionOrder(After = nameof(ProjectSystem))]
-    [ExportIProjectSystem(nameof(MiscellanousFiles)), Shared]
+    //[ExtensionOrder(After = nameof(ProjectSystem))]
+    [ExportIProjectSystem("Misc files", after: nameof(ProjectSystem)), Shared]
     public class MiscellanousFiles : IProjectSystem
     {
         private readonly string miscFileExtension = ".cs";