save namespaces for later when using defered loader, otherwise they are lost

src/Markup/Avalonia.Markup.Xaml/MarkupExtensions/StaticExtension.cs

@@ -1,18 +1,12 @@
 // Copyright (c) The Avalonia Project. All rights reserved.
 // Licensed under the MIT license. See licence.md file in the project root for full license information.
 
-using Portable.Xaml;
-using Portable.Xaml.ComponentModel;
-using Portable.Xaml.Markup;
 using System;
-using System.Collections.Generic;
-using System.Linq;
 
 namespace Avalonia.Markup.Xaml.MarkupExtensions
 {
 #if !OMNIXAML
 
-    //TODO: check do we need something more than std Portable.xaml static??
     public class StaticExtension : Portable.Xaml.Markup.StaticExtension
     {
         public StaticExtension()
@@ -26,19 +20,6 @@ namespace Avalonia.Markup.Xaml.MarkupExtensions
 
         public override object ProvideValue(IServiceProvider serviceProvider)
         {
-            var tdc = (ITypeDescriptorContext)serviceProvider;
-            var ns = tdc.GetService<IXamlNamespaceResolver>();
-
-            if (!ns.GetNamespacePrefixes().Any())
-            {
-               //TODO: issue of portable.xaml ??? investigate
-                var cvp = tdc.GetService<IRootObjectProvider>();
-                var pvt = tdc.GetService<IProvideValueTarget>(); 
-                //ok we have a problem namespaces shouldn't be empty
-                var nslist = ns.GetNamespacePrefixes() as IList<NamespaceDeclaration>;
-                nslist.Add(new NamespaceDeclaration("https://github.com/avaloniaui", ""));
-                //this is just a hack
-            }
             return base.ProvideValue(serviceProvider);
         }
     }

src/Markup/Avalonia.Markup.Xaml/Templates/TemplateContent.cs

@@ -1,9 +1,8 @@
 // Copyright (c) The Avalonia Project. All rights reserved.
 // Licensed under the MIT license. See licence.md file in the project root for full license information.
 
-using System.Collections.Generic;
 using Avalonia.Controls;
-using Avalonia.Markup.Xaml.Context;
+using System.Collections.Generic;
 
 namespace Avalonia.Markup.Xaml.Templates
 {
@@ -12,21 +11,24 @@ namespace Avalonia.Markup.Xaml.Templates
 
     public class TemplateContent
     {
-        public TemplateContent()
-        {
-        }
-
-        public TemplateContent(XamlReader reader)
+        public TemplateContent(IEnumerable<NamespaceDeclaration> namespaces, XamlReader reader)
         {
             List = new XamlNodeList(reader.SchemaContext);
+
+            //we need to rpeserve all namespace and prefixes to writer
+            //otherwise they are lost. a bug in Portable.xaml or by design ??
+            foreach (var ns in namespaces)
+            {
+                List.Writer.WriteNamespace(ns);
+            }
+
             XamlServices.Transform(reader, List.Writer);
         }
 
-        public XamlNodeList List { get; set; }
+        public XamlNodeList List { get; }
 
         public IControl Load()
         {
-            //return (IControl)XamlServices.Load(List.GetReader());
             return (IControl)AvaloniaXamlLoader.LoadFromReader(List.GetReader());
         }
 
@@ -37,6 +39,7 @@ namespace Avalonia.Markup.Xaml.Templates
     }
 #else
 
+    using Avalonia.Markup.Xaml.Context;
     using OmniXaml;
     using OmniXaml.ObjectAssembler;
 

src/Markup/Avalonia.Markup.Xaml/Templates/TemplateLoader.cs

@@ -1,19 +1,21 @@
 // Copyright (c) The Avalonia Project. All rights reserved.
 // Licensed under the MIT license. See licence.md file in the project root for full license information.
 
-using System.Collections.Generic;
-
 namespace Avalonia.Markup.Xaml.Templates
 {
 #if !OMNIXAML
+
     using Portable.Xaml;
+    using Portable.Xaml.ComponentModel;
     using System;
 
     public class TemplateLoader : XamlDeferringLoader
     {
         public override object Load(XamlReader xamlReader, IServiceProvider serviceProvider)
         {
-            return new TemplateContent(xamlReader);
+            var tdc = (ITypeDescriptorContext)serviceProvider;
+            var ns = tdc.GetService<IXamlNamespaceResolver>();
+            return new TemplateContent(ns.GetNamespacePrefixes(), xamlReader);
         }
 
         public override XamlReader Save(object value, IServiceProvider serviceProvider)
@@ -21,8 +23,10 @@ namespace Avalonia.Markup.Xaml.Templates
             return ((TemplateContent)value).List.GetReader();
         }
     }
+
 #else
 
+    using System.Collections.Generic;
     using OmniXaml;
 
     public class TemplateLoader : IDeferredLoader