Initial support for VaryByHeader (ref: #6)

Author: pstarkov

DevTrends.MvcDonutCaching/CacheSettings.cs

@@ -28,6 +28,14 @@ public class CacheSettings
         /// </value>
         public string VaryByParam { get; set; }
 
+        /// <summary>
+        /// Gets or sets the VaryByHeader cache parameter.
+        /// </summary>
+        /// <value>
+        /// The VaryByHeader cache parameter.
+        /// </value>
+        public string VaryByHeader { get; set; }
+
         /// <summary>
         /// Gets or sets the VaryByCustom cache parameter.
         /// </summary>

DevTrends.MvcDonutCaching/DonutOutputCacheAttribute.cs

@@ -68,6 +68,15 @@ public string VaryByParam
             set;
         }
 
+        /// <summary>
+        /// Gets or sets the vary-by-header value.
+        /// </summary>
+        public string VaryByHeader
+        {
+            get;
+            set;
+        }
+
         /// <summary>
         /// Gets or sets the vary-by-custom value.
         /// </summary>
@@ -262,12 +271,13 @@ protected CacheSettings BuildCacheSettings()
                 cacheSettings = new CacheSettings
                 {
                     IsCachingEnabled = CacheSettingsManager.IsCachingEnabledGlobally,
-                    Duration = Duration,
-                    VaryByCustom = VaryByCustom,
-                    VaryByParam = VaryByParam,
-                    Location = (int)Location == -1 ? OutputCacheLocation.Server : Location,
-                    NoStore = NoStore,
-                    Options = Options,
+                    Duration         = Duration,
+                    VaryByCustom     = VaryByCustom,
+                    VaryByParam      = VaryByParam,
+                    VaryByHeader     = VaryByHeader,
+                    Location         = (int)Location == -1 ? OutputCacheLocation.Server : Location,
+                    NoStore          = NoStore,
+                    Options          = Options,
                 };
             }
             else
@@ -277,12 +287,13 @@ protected CacheSettings BuildCacheSettings()
                 cacheSettings = new CacheSettings
                 {
                     IsCachingEnabled = CacheSettingsManager.IsCachingEnabledGlobally && cacheProfile.Enabled,
-                    Duration = Duration == -1 ? cacheProfile.Duration : Duration,
-                    VaryByCustom = VaryByCustom ?? cacheProfile.VaryByCustom,
-                    VaryByParam = VaryByParam ?? cacheProfile.VaryByParam,
-                    Location = (int)Location == -1 ? ((int)cacheProfile.Location == -1 ? OutputCacheLocation.Server : cacheProfile.Location) : Location,
-                    NoStore = _noStore.HasValue ? _noStore.Value : cacheProfile.NoStore,
-                    Options = Options,
+                    Duration         = Duration == -1 ? cacheProfile.Duration : Duration,
+                    VaryByCustom     = VaryByCustom ?? cacheProfile.VaryByCustom,
+                    VaryByParam      = VaryByParam ?? cacheProfile.VaryByParam,
+                    VaryByHeader     = VaryByHeader ?? cacheProfile.VaryByHeader,
+                    Location         = (int)Location == -1 ? ((int)cacheProfile.Location == -1 ? OutputCacheLocation.Server : cacheProfile.Location) : Location,
+                    NoStore          = _noStore.HasValue ? _noStore.Value : cacheProfile.NoStore,
+                    Options          = Options,
                 };
             }
 

DevTrends.MvcDonutCaching/KeyGenerator.cs

@@ -83,7 +83,6 @@ public string GenerateKey(ControllerContext context, CacheSettings cacheSettings
             if (!context.IsChildAction)
             {
                 // note that route values take priority over form values and form values take priority over query string values
-
                 if ((cacheSettings.Options & OutputCacheOptions.IgnoreFormData) != OutputCacheOptions.IgnoreFormData)
                 {
                     foreach (var formKey in context.HttpContext.Request.Form.AllKeys)
@@ -107,7 +106,7 @@ public string GenerateKey(ControllerContext context, CacheSettings cacheSettings
                 {
                     foreach (var queryStringKey in context.HttpContext.Request.QueryString.AllKeys)
                     {
-                        // queryStringKey is null if url has qs name without value. e.g. test.com?q
+                        // queryStringKey is null if url has as name without value. e.g. test.com?q
                         if (queryStringKey == null || routeValues.ContainsKey(queryStringKey.ToLowerInvariant()))
                         {
                             continue;
@@ -144,6 +143,16 @@ public string GenerateKey(ControllerContext context, CacheSettings cacheSettings
                             context.HttpContext.ApplicationInstance.GetVaryByCustomString(HttpContext.Current, cacheSettings.VaryByCustom);
             }
 
+            if (!string.IsNullOrEmpty(cacheSettings.VaryByHeader))
+            {
+                var headers = cacheSettings.VaryByHeader.ToLowerInvariant().Split(new[] { ';' }, StringSplitOptions.RemoveEmptyEntries);
+                var existingHeaders = context.HttpContext.Request.Headers.AllKeys.Where(x => headers.Contains(x.ToLowerInvariant()));
+                foreach (var header in existingHeaders)
+                {
+                    routeValues[header] = context.HttpContext.Request.Headers[header];
+                }
+            }
+
             var key = _keyBuilder.BuildKey(controllerName, actionName, routeValues);
 
             return key;