Added IsNullOrEmptyHtml extension method for HtmlString

src/storm.umbraco.contrib/Extensions/HtmlStringExtensions.cs

@@ -0,0 +1,27 @@
+using HtmlAgilityPack;
+using System.Web;
+
+namespace storm.umbraco.contrib.Extensions
+{
+    public static class HtmlStringExtensions
+    {
+        /// <summary>
+        /// Indicates whether the specified <see cref="HtmlString">HtmlString</see> is null or contains only html tags with no inner text.         
+        /// </summary>
+        /// <param name="value">The HtmlString to test.</param>
+        /// <returns></returns>
+        public static bool IsNullOrEmptyHtml(this IHtmlString value)
+        {
+            if (value == null)
+            {
+                return true;
+            }
+
+            var document = new HtmlDocument();
+            document.LoadHtml(value.ToHtmlString());
+            string textValue = HtmlEntity.DeEntitize(document.DocumentNode.InnerText);
+
+            return string.IsNullOrWhiteSpace(textValue);
+        }
+    }
+}

tests/contrib.tests/Extensions/IsNullOrEmptyHtmlTests.cs

@@ -0,0 +1,32 @@
+using storm.umbraco.contrib.Extensions;
+using System.Web;
+using Xunit;
+
+namespace contrib.tests.Extensions
+{
+    public class IsNullOrEmptyHtmlTests
+    {
+        [Fact]
+        public void Htmlstring_NullOrEmptyHtml_Null()
+        {
+            IHtmlString value = null;
+
+            Assert.True(value.IsNullOrEmptyHtml());
+        }
+
+        [Fact]
+        public void Htmlstring_NullOrEmptyHtml_EmptyHtml()
+        {
+            IHtmlString value = new HtmlString("<p> </p>");
+
+            Assert.True(value.IsNullOrEmptyHtml());
+        }
+
+        [Fact]
+        public void Htmlstring_NullOrEmptyHtml_HtmlWithContent()
+        {
+            IHtmlString value = new HtmlString("<p>Lorem ipsum dolor sit amet.</p>");
+            Assert.False(value.IsNullOrEmptyHtml());
+        }
+    }
+}

tests/contrib.tests/contrib.tests.csproj

@@ -20,4 +20,8 @@
     <ProjectReference Include="..\..\src\storm.umbraco.contrib\storm.umbraco.contrib.csproj" />
   </ItemGroup>
 
+  <ItemGroup>
+    <Reference Include="System.Web" />
+  </ItemGroup>
+
 </Project>