4 files changed, 87 insertions, 1 deletions

diff --git a/src/wixext/BalCompiler.cs b/src/wixext/BalCompiler.cs
index da32234c..33400f3b 100644
--- a/src/wixext/BalCompiler.cs
+++ b/src/wixext/BalCompiler.cs
@@ -197,6 +197,15 @@ namespace WixToolset.Bal
                     {
                         switch (attribute.Name.LocalName)
                         {
+                            case "BAFactoryAssembly":
+                                if (YesNoType.Yes == this.ParseHelper.GetAttributeYesNoValue(sourceLineNumbers, attribute))
+                                {
+                                    section.AddTuple(new WixBalBAFactoryAssemblyTuple(sourceLineNumbers)
+                                    {
+                                        PayloadId = payloadId,
+                                    });
+                                }
+                                break;
                             case "BAFunctions":
                                 if (YesNoType.Yes == this.ParseHelper.GetAttributeYesNoValue(sourceLineNumbers, attribute))
                                 {
diff --git a/src/wixext/Tuples/BalTupleDefinitions.cs b/src/wixext/Tuples/BalTupleDefinitions.cs
index 676db9f6..48199f95 100644
--- a/src/wixext/Tuples/BalTupleDefinitions.cs
+++ b/src/wixext/Tuples/BalTupleDefinitions.cs
@@ -4,9 +4,11 @@ namespace WixToolset.Bal
 {
     using System;
     using WixToolset.Data;
+    using WixToolset.Data.Burn;
 
     public enum BalTupleDefinitionType
     {
+        WixBalBAFactoryAssembly,
         WixBalBAFunctions,
         WixBalCondition,
         WixMbaPrereqInformation,
@@ -32,6 +34,9 @@ namespace WixToolset.Bal
         {
             switch (type)
             {
+                case BalTupleDefinitionType.WixBalBAFactoryAssembly:
+                    return BalTupleDefinitions.WixBalBAFactoryAssembly;
+
                 case BalTupleDefinitionType.WixBalBAFunctions:
                     return BalTupleDefinitions.WixBalBAFunctions;
 
@@ -51,5 +56,15 @@ namespace WixToolset.Bal
                     throw new ArgumentOutOfRangeException(nameof(type));
             }
         }
+
+        static BalTupleDefinitions()
+        {
+            WixBalBAFactoryAssembly.AddTag(BurnConstants.BootstrapperApplicationDataTupleDefinitionTag);
+            WixBalBAFunctions.AddTag(BurnConstants.BootstrapperApplicationDataTupleDefinitionTag);
+            WixBalCondition.AddTag(BurnConstants.BootstrapperApplicationDataTupleDefinitionTag);
+            WixMbaPrereqInformation.AddTag(BurnConstants.BootstrapperApplicationDataTupleDefinitionTag);
+            WixStdbaOptions.AddTag(BurnConstants.BootstrapperApplicationDataTupleDefinitionTag);
+            WixStdbaOverridableVariable.AddTag(BurnConstants.BootstrapperApplicationDataTupleDefinitionTag);
+        }
     }
 }
diff --git a/src/wixext/Tuples/WixBalBAFactoryAssemblyTuple.cs b/src/wixext/Tuples/WixBalBAFactoryAssemblyTuple.cs
new file mode 100644
index 00000000..e33ea562
--- /dev/null
+++ b/src/wixext/Tuples/WixBalBAFactoryAssemblyTuple.cs
@@ -0,0 +1,47 @@
+// Copyright (c) .NET Foundation and contributors. All rights reserved. Licensed under the Microsoft Reciprocal License. See LICENSE.TXT file in the project root for full license information.
+
+namespace WixToolset.Bal
+{
+    using WixToolset.Data;
+    using WixToolset.Bal.Tuples;
+
+    public static partial class BalTupleDefinitions
+    {
+        public static readonly IntermediateTupleDefinition WixBalBAFactoryAssembly = new IntermediateTupleDefinition(
+            BalTupleDefinitionType.WixBalBAFactoryAssembly.ToString(),
+            new[]
+            {
+                new IntermediateFieldDefinition(nameof(WixBalBAFactoryTupleFields.PayloadId), IntermediateFieldType.String),
+            },
+            typeof(WixBalBAFactoryAssemblyTuple));
+    }
+}
+
+namespace WixToolset.Bal.Tuples
+{
+    using WixToolset.Data;
+
+    public enum WixBalBAFactoryTupleFields
+    {
+        PayloadId,
+    }
+
+    public class WixBalBAFactoryAssemblyTuple : IntermediateTuple
+    {
+        public WixBalBAFactoryAssemblyTuple() : base(BalTupleDefinitions.WixBalBAFactoryAssembly, null, null)
+        {
+        }
+
+        public WixBalBAFactoryAssemblyTuple(SourceLineNumber sourceLineNumber, Identifier id = null) : base(BalTupleDefinitions.WixBalBAFactoryAssembly, sourceLineNumber, id)
+        {
+        }
+
+        public IntermediateField this[WixBalBAFactoryTupleFields index] => this.Fields[(int)index];
+
+        public string PayloadId
+        {
+            get => this.Fields[(int)WixBalBAFactoryTupleFields.PayloadId].AsString();
+            set => this.Set((int)WixBalBAFactoryTupleFields.PayloadId, value);
+        }
+    }
+}
\ No newline at end of file
diff --git a/src/wixext/bal.xsd b/src/wixext/bal.xsd
index 3081a279..52f9142f 100644
--- a/src/wixext/bal.xsd
+++ b/src/wixext/bal.xsd
@@ -9,7 +9,7 @@
               xmlns="http://wixtoolset.org/schemas/v4/wxs/bal">
     <xs:annotation>
         <xs:documentation>
-            The source code schema for the WiX Toolset Burn User Experience Extension.
+            The source code schema for the WiX Toolset Bootstrapper Application Layer Extension.
         </xs:documentation>
     </xs:annotation>
 
@@ -215,10 +215,25 @@
         </xs:complexType>
     </xs:element>
 
+    <xs:attribute name="BAFactoryAssembly" type="YesNoType">
+        <xs:annotation>
+            <xs:documentation>
+                When set to "yes", DotNetCoreBootstrapperApplicationHost will load the DLL and instantiate the type with the BootstrapperApplicationFactoryAttribute.
+                There must be corresponding deps.json and runtimeconfig.json files (set EnableDynamicLoading to True in the .NET Core project).
+                The .NET Core project must have been published, not just built.
+                Only one payload may be marked with this attribute set to "yes".
+            </xs:documentation>
+            <xs:appinfo>
+                <xse:parent namespace="http://wixtoolset.org/schemas/v4/wxs" ref="Payload" />
+            </xs:appinfo>
+        </xs:annotation>
+    </xs:attribute>
+
     <xs:attribute name="BAFunctions" type="YesNoType">
         <xs:annotation>
             <xs:documentation>
                 When set to "yes", WixStdBA will load the DLL and work with it to handle BA messages.
+                Only one payload may be marked with this attribute set to "yes".
             </xs:documentation>
             <xs:appinfo>
                 <xse:parent namespace="http://wixtoolset.org/schemas/v4/wxs" ref="Payload" />