From 774219b2ef6021923dabc931e2436c7150d09e29 Mon Sep 17 00:00:00 2001
From: Ajay Bhargav Baaskaran <ajbaaska@microsoft.com>
Date: Wed, 19 Aug 2015 17:46:52 -0700
Subject: [PATCH] [Fixes #2788] Added a sample taghelper that handles IE
 conditional comments

---
 .../Controllers/TagHelperController.cs        | 15 ++++++++
 .../TagHelpers/CommentMode.cs                 | 12 ++++++
 .../TagHelpers/ConditionalCommentTagHelper.cs | 37 +++++++++++++++++++
 .../Views/TagHelper/ConditionalComment.cshtml |  9 +++++
 4 files changed, 73 insertions(+)
 create mode 100644 samples/TagHelperSample.Web/Controllers/TagHelperController.cs
 create mode 100644 samples/TagHelperSample.Web/TagHelpers/CommentMode.cs
 create mode 100644 samples/TagHelperSample.Web/TagHelpers/ConditionalCommentTagHelper.cs
 create mode 100644 samples/TagHelperSample.Web/Views/TagHelper/ConditionalComment.cshtml

diff --git a/samples/TagHelperSample.Web/Controllers/TagHelperController.cs b/samples/TagHelperSample.Web/Controllers/TagHelperController.cs
new file mode 100644
index 0000000000..7e5873bfdf
--- /dev/null
+++ b/samples/TagHelperSample.Web/Controllers/TagHelperController.cs
@@ -0,0 +1,15 @@
+// Copyright (c) .NET Foundation. All rights reserved.
+// Licensed under the Apache License, Version 2.0. See License.txt in the project root for license information.
+
+using Microsoft.AspNet.Mvc;
+
+namespace TagHelperSample.Web.Controllers
+{
+    public class TagHelperController : Controller
+    {
+        public IActionResult ConditionalComment()
+        {
+            return View();
+        }
+    }
+}
diff --git a/samples/TagHelperSample.Web/TagHelpers/CommentMode.cs b/samples/TagHelperSample.Web/TagHelpers/CommentMode.cs
new file mode 100644
index 0000000000..f671d1a3c9
--- /dev/null
+++ b/samples/TagHelperSample.Web/TagHelpers/CommentMode.cs
@@ -0,0 +1,12 @@
+// Copyright (c) .NET Foundation. All rights reserved.
+// Licensed under the Apache License, Version 2.0. See License.txt in the project root for license information.
+
+namespace TagHelperSample.Web
+{
+    public enum CommentMode
+    {
+        DownlevelHidden = 0,
+
+        DownlevelRevealed = 1
+    }
+}
diff --git a/samples/TagHelperSample.Web/TagHelpers/ConditionalCommentTagHelper.cs b/samples/TagHelperSample.Web/TagHelpers/ConditionalCommentTagHelper.cs
new file mode 100644
index 0000000000..1021d21b9f
--- /dev/null
+++ b/samples/TagHelperSample.Web/TagHelpers/ConditionalCommentTagHelper.cs
@@ -0,0 +1,37 @@
+// Copyright (c) .NET Foundation. All rights reserved.
+// Licensed under the Apache License, Version 2.0. See License.txt in the project root for license information.
+
+using Microsoft.AspNet.Razor.Runtime.TagHelpers;
+
+namespace TagHelperSample.Web
+{
+    [TargetElement("iecondition")]
+    public class ConditionalCommentTagHelper : TagHelper
+    {
+        public CommentMode Mode { get; set; }
+
+        public string Condition { get; set; }
+
+        public override void Process(TagHelperContext context, TagHelperOutput output)
+        {
+            output.TagName = null;
+
+            var modeModifier = string.Empty;
+
+            if (Mode == CommentMode.DownlevelHidden)
+            {
+                modeModifier = "--";
+            }
+
+            output.PreContent.Append("<!");
+            output.PreContent.Append(modeModifier);
+            output.PreContent.Append("[if ");
+            output.PreContent.Append(Condition);
+            output.PreContent.Append("]>");
+
+            output.PostContent.Append("<![endif]");
+            output.PostContent.Append(modeModifier);
+            output.PostContent.Append(">");
+        }
+    }
+}
diff --git a/samples/TagHelperSample.Web/Views/TagHelper/ConditionalComment.cshtml b/samples/TagHelperSample.Web/Views/TagHelper/ConditionalComment.cshtml
new file mode 100644
index 0000000000..f97c2b9a7f
--- /dev/null
+++ b/samples/TagHelperSample.Web/Views/TagHelper/ConditionalComment.cshtml
@@ -0,0 +1,9 @@
+@using TagHelperSample.Web
+@addTagHelper "*, TagHelperSample.Web"
+
+<iecondition mode="@CommentMode.DownlevelRevealed" condition="gt IE 7">
+    <p>Content visible to all browsers newer than Internet Explorer 7.</p>
+</iecondition>
+<iecondition mode="@CommentMode.DownlevelHidden" condition="IE 7">
+    <p>Content visible only to Internet Explorer 7 users.</p>
+</iecondition>