1 files changed, 110 insertions, 0 deletions

diff --git a/src/WixToolset.Data/Message.cs b/src/WixToolset.Data/Message.cs
new file mode 100644
index 00000000..6cd4105c
--- /dev/null
+++ b/src/WixToolset.Data/Message.cs
@@ -0,0 +1,110 @@
+// 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.Data
+{
+    using System;
+    using System.Resources;
+
+    /// <summary>
+    /// Event args for message events.
+    /// </summary>
+    public class Message
+    {
+        /// <summary>
+        /// Creates a new Message using a format string.
+        /// </summary>
+        /// <param name="sourceLineNumbers">Source line numbers for the message.</param>
+        /// <param name="level">Message level.</param>
+        /// <param name="id">Id for the message.</param>
+        /// <param name="format">Format .</param>
+        /// <param name="messageArgs">Arguments for the format string.</param>
+        public Message(SourceLineNumber sourceLineNumbers, MessageLevel level, int id, string format, params object[] messageArgs)
+        {
+            this.SourceLineNumbers = sourceLineNumbers;
+            this.Level = level;
+            this.Id = id;
+            this.ResourceNameOrFormat = format;
+            this.MessageArgs = messageArgs;
+        }
+
+        /// <summary>
+        /// Creates a new Message using a format string from a resource manager.
+        /// </summary>
+        /// <param name="sourceLineNumbers">Source line numbers for the message.</param>
+        /// <param name="level">Message level.</param>
+        /// <param name="id">Id for the message.</param>
+        /// <param name="resourceManager">Resource manager.</param>
+        /// <param name="resourceName">Name of the resource.</param>
+        /// <param name="messageArgs">Arguments for the format string.</param>
+        public Message(SourceLineNumber sourceLineNumbers, MessageLevel level, int id, ResourceManager resourceManager, string resourceName, params object[] messageArgs)
+        {
+            this.SourceLineNumbers = sourceLineNumbers;
+            this.Level = level;
+            this.Id = id;
+            this.ResourceManager = resourceManager;
+            this.ResourceNameOrFormat = resourceName;
+            this.MessageArgs = messageArgs;
+        }
+
+        /// <summary>
+        /// Gets the source line numbers.
+        /// </summary>
+        /// <value>The source line numbers.</value>
+        public SourceLineNumber SourceLineNumbers { get; }
+
+        /// <summary>
+        /// Gets the Id for the message.
+        /// </summary>
+        /// <value>The Id for the message.</value>
+        public int Id { get; }
+
+        /// <summary>
+        /// Gets the resource manager for this event args.
+        /// </summary>
+        /// <value>The resource manager for this event args.</value>
+        public ResourceManager ResourceManager { get; }
+
+        /// <summary>
+        /// Gets the name of the resource or format string if no resource manager was provided.
+        /// </summary>
+        /// <value>The name of the resource or format string.</value>
+        public string ResourceNameOrFormat { get; }
+
+        /// <summary>
+        /// Gets or sets the <see cref="MessageLevel"/> for the message.
+        /// </summary>
+        /// <value>The <see cref="MessageLevel"/> for the message.</value>
+        public MessageLevel Level { get; private set; }
+
+        /// <summary>
+        /// Gets the arguments for the format string.
+        /// </summary>
+        /// <value>The arguments for the format string.</value>
+        public object[] MessageArgs { get; }
+
+        /// <summary>
+        /// Makes a warning an error.
+        /// </summary>
+        public void ElevateWarningToError()
+        {
+            if (this.Level != MessageLevel.Warning)
+            {
+                throw new InvalidOperationException($"Cannot elevate {this.Level.ToString()} Message to an Error. Only Warning Messages can be elevated to an Error.");
+            }
+
+            this.Level = MessageLevel.Error;
+        }
+
+        public override string ToString()
+        {
+            if (this.ResourceManager == null)
+            {
+                return String.Format(this.ResourceNameOrFormat, this.MessageArgs);
+            }
+            else
+            {
+                return String.Format(this.ResourceManager.GetString(this.ResourceNameOrFormat), this.MessageArgs);
+            }
+        }
+    }
+}