2 files changed, 11 insertions, 1 deletions

diff --git a/src/WixToolset.Extensibility/Data/IResolveContext.cs b/src/WixToolset.Extensibility/Data/IResolveContext.cs
index 8af79cff..608ce5d5 100644
--- a/src/WixToolset.Extensibility/Data/IResolveContext.cs
+++ b/src/WixToolset.Extensibility/Data/IResolveContext.cs
@@ -5,7 +5,6 @@ namespace WixToolset.Extensibility.Data
     using System;
     using System.Collections.Generic;
     using WixToolset.Data;
-    using WixToolset.Extensibility.Services;
 
     public interface IResolveContext
     {
@@ -24,5 +23,7 @@ namespace WixToolset.Extensibility.Data
         Intermediate IntermediateRepresentation { get; set; }
 
         IEnumerable<Localization> Localizations { get; set; }
+
+        bool AllowUnresolvedVariables { get; set; }
     }
 }
diff --git a/src/WixToolset.Extensibility/Services/IVariableResolver.cs b/src/WixToolset.Extensibility/Services/IVariableResolver.cs
index 5d647fda..a108e146 100644
--- a/src/WixToolset.Extensibility/Services/IVariableResolver.cs
+++ b/src/WixToolset.Extensibility/Services/IVariableResolver.cs
@@ -25,6 +25,15 @@ namespace WixToolset.Extensibility.Services
         IVariableResolution ResolveVariables(SourceLineNumber sourceLineNumbers, string value);
 
         /// <summary>
+        /// Resolve the wix variables in a value.
+        /// </summary>
+        /// <param name="sourceLineNumbers">The source line information for the value.</param>
+        /// <param name="value">The value to resolve.</param>
+        /// <param name="errorOnUnknown">true if unknown variables should throw errors.</param>
+        /// <returns>The resolved value.</returns>
+        IVariableResolution ResolveVariables(SourceLineNumber sourceLineNumbers, string value, bool errorOnUnknown);
+
+        /// <summary>
         /// Try to find localization information for dialog and (optional) control.
         /// </summary>
         /// <param name="dialog">Dialog identifier.</param>