MonoRail/Castle.MonoRail.Framework/Filters/LocalizationFilter.cs

   1 // Copyright 2004-2007 Castle Project - http://www.castleproject.org/
   2 //
   3 // Licensed under the Apache License, Version 2.0 (the "License");
   4 // you may not use this file except in compliance with the License.
   5 // You may obtain a copy of the License at
   6 //
   7 //     http://www.apache.org/licenses/LICENSE-2.0
   8 //
   9 // Unless required by applicable law or agreed to in writing, software
  10 // distributed under the License is distributed on an "AS IS" BASIS,
  11 // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  12 // See the License for the specific language governing permissions and
  13 // limitations under the License.
  14
  15 namespace Castle.MonoRail.Framework.Filters
  16 {
  17         using System;
  18         using System.Configuration;
  19         using System.Globalization;
  20         using System.Threading;
  21
  22         /// <summary>
  23         /// Enum to identify where a value is stored.
  24         /// </summary>
  25         public enum RequestStore
  26         {
  27                 /// <summary>
  28                 /// Value is stored in the Session object.
  29                 /// </summary>
  30                 Session = 1,
  31                 /// <summary>
  32                 /// Value is stored in a cookie object.
  33                 /// </summary>
  34                 Cookie = 2,
  35                 /// <summary>
  36                 /// Value is stored in the querystring.
  37                 /// </summary>
  38                 QueryString = 3,
  39                 /// <summary>
  40                 /// Value is stored in the form collection.
  41                 /// </summary>
  42                 Form = 4,
  43                 /// <summary>
  44                 /// Value is stored in either query string or form collection.
  45                 /// </summary>
  46                 Params = 5
  47         }
  48
  49         /// <summary>
  50         /// The LocalizationFilter can be used to determine the culture to use
  51         /// for resources and UI.
  52         /// </summary>
  53         public class LocalizationFilter : IFilter, IFilterAttributeAware
  54         {
  55                 private LocalizationFilterAttribute setup;
  56
  57                 #region IFilterAttributeAware Members
  58
  59                 public FilterAttribute Filter
  60                 {
  61                         set
  62                         {
  63                                 if (!(value is LocalizationFilterAttribute))
  64                                 {
  65                                         String message = "LocalizationFilter can only be defined by a LocalizationFilterAttribute.";
  66                                         throw new ConfigurationErrorsException(message);
  67                                 }
  68
  69                                 setup = value as LocalizationFilterAttribute;
  70                         }
  71                 }
  72
  73                 #endregion
  74
  75                 #region IFilter Members
  76
  77                 public bool Perform(ExecuteEnum exec, IRailsEngineContext context, Controller controller)
  78                 {
  79                         try
  80                         {
  81                                 String localeId = GetLocaleId(context);
  82
  83                                 if (localeId == null && setup.UseBrowser)
  84                                         localeId = GetUserLanguage(context.Request);
  85
  86                                 if (localeId != null)
  87                                 {
  88                                         CultureInfo culture = CultureInfo.CreateSpecificCulture(localeId);
  89
  90                                         Thread.CurrentThread.CurrentCulture = culture;
  91                                         Thread.CurrentThread.CurrentUICulture = culture;
  92                                 }
  93                         }
  94                         catch
  95                         {
  96                                 if (setup.FailOnError) throw;
  97                         }
  98
  99                         return true;
 100                 }
 101
 102                 #endregion
 103
 104                 #region Get locale id from the store
 105
 106                 private String GetUserLanguage(IRequest request)
 107                 {
 108                         if (request.UserLanguages != null && request.UserLanguages.Length > 0)
 109                                 return request.UserLanguages[0];
 110
 111                         return null;
 112                 }
 113
 114                 private String GetLocaleId(IRailsEngineContext context)
 115                 {
 116                         switch(setup.Store)
 117                         {
 118                                 case RequestStore.Session:
 119                                         return context.Session[setup.Key] as String;
 120                                 case RequestStore.Cookie:
 121                                         return context.Request.ReadCookie(setup.Key);
 122                                 case RequestStore.QueryString:
 123                                         return context.Request.QueryString[setup.Key];
 124                                 case RequestStore.Form:
 125                                         return context.Request.Form[setup.Key];
 126                                 case RequestStore.Params:
 127                                         return context.Request.Params[setup.Key];
 128                         }
 129
 130                         return null;
 131                 }
 132
 133                 #endregion
 134         }
 135 }