mcs/class/System.Web.Mvc3/Mvc/HttpRequestExtensions.cs

   1 namespace System.Web.Mvc {
   2     using System;
   3
   4     public static class HttpRequestExtensions {
   5         internal const string XHttpMethodOverrideKey = "X-HTTP-Method-Override";
   6
   7         public static string GetHttpMethodOverride(this HttpRequestBase request) {
   8             if (request == null) {
   9                 throw new ArgumentNullException("request");
  10             }
  11
  12             string incomingVerb = request.HttpMethod;
  13
  14             if (!String.Equals(incomingVerb, "POST", StringComparison.OrdinalIgnoreCase)) {
  15                 return incomingVerb;
  16             }
  17
  18             string verbOverride = null;
  19             string headerOverrideValue = request.Headers[XHttpMethodOverrideKey];
  20             if (!String.IsNullOrEmpty(headerOverrideValue)) {
  21                 verbOverride = headerOverrideValue;
  22             }
  23             else {
  24                 string formOverrideValue = request.Form[XHttpMethodOverrideKey];
  25                 if (!String.IsNullOrEmpty(formOverrideValue)) {
  26                     verbOverride = formOverrideValue;
  27                 }
  28                 else {
  29                     string queryStringOverrideValue = request.QueryString[XHttpMethodOverrideKey];
  30                     if (!String.IsNullOrEmpty(queryStringOverrideValue)) {
  31                         verbOverride = queryStringOverrideValue;
  32                     }
  33                 }
  34             }
  35             if (verbOverride != null) {
  36                 if (!String.Equals(verbOverride, "GET", StringComparison.OrdinalIgnoreCase) &&
  37                     !String.Equals(verbOverride, "POST", StringComparison.OrdinalIgnoreCase)) {
  38                     incomingVerb = verbOverride;
  39                 }
  40             }
  41             return incomingVerb;
  42         }
  43     }
  44 }