src/DotNetOpenAuth/XrdsPublisher.cs

   1 //-----------------------------------------------------------------------
   2 // <copyright file="XrdsPublisher.cs" company="Andrew Arnott">
   3 //     Copyright (c) Andrew Arnott. All rights reserved.
   4 // </copyright>
   5 //-----------------------------------------------------------------------
   6
   7 namespace DotNetOpenAuth {
   8         using System;
   9         using System.Collections.Generic;
  10         using System.ComponentModel;
  11         using System.Diagnostics.CodeAnalysis;
  12         using System.Text;
  13         using System.Web;
  14         using System.Web.UI;
  15         using System.Web.UI.WebControls;
  16         using DotNetOpenAuth.Messaging;
  17         using DotNetOpenAuth.Yadis;
  18
  19         /// <summary>
  20         /// The locations the YADIS protocol describes can contain a reference
  21         /// to an XRDS document.
  22         /// </summary>
  23         [SuppressMessage("Microsoft.Naming", "CA1704:IdentifiersShouldBeSpelledCorrectly", MessageId = "Xrds", Justification = "Correct spelling")]
  24         [Flags]
  25         public enum XrdsUrlLocations {
  26                 /// <summary>
  27                 /// Indicates XRDS document referencing from an HTTP protocol header (outside the HTML).
  28                 /// </summary>
  29                 HttpHeader = 0x1,
  30
  31                 /// <summary>
  32                 /// Indicates XRDS document referencing from within an HTML page's &lt;HEAD&gt; tag.
  33                 /// </summary>
  34                 HtmlMeta = 0x2,
  35
  36                 /// <summary>
  37                 /// Indicates XRDS document referencing in both HTTP headers and HTML HEAD tags.
  38                 /// </summary>
  39                 Both = 0x3,
  40         }
  41
  42         /// <summary>
  43         /// An ASP.NET control that advertises an XRDS document and even responds to specially
  44         /// crafted requests to retrieve it.
  45         /// </summary>
  46         [DefaultProperty("XrdsLocation")]
  47         [ToolboxData("<{0}:XrdsPublisher runat=server></{0}:XrdsPublisher>")]
  48         public class XrdsPublisher : Control {
  49                 /// <summary>
  50                 /// The view state key to ues for storing the value of the <see cref="XrdsUrl"/> property.
  51                 /// </summary>
  52                 private const string XrdsUrlViewStateKey = "XrdsUrl";
  53
  54                 /// <summary>
  55                 /// The default value for the <see cref="XrdsAdvertisement"/> property.
  56                 /// </summary>
  57                 private const XrdsUrlLocations XrdsAdvertisementDefault = XrdsUrlLocations.HttpHeader;
  58
  59                 /// <summary>
  60                 /// The view state key to ues for storing the value of the <see cref="XrdsAdvertisement"/> property.
  61                 /// </summary>
  62                 private const string XrdsAdvertisementViewStateKey = "XrdsAdvertisement";
  63
  64                 /// <summary>
  65                 /// The default value for the <see cref="XrdsAutoAnswer"/> property.
  66                 /// </summary>
  67                 private const bool XrdsAutoAnswerDefault = true;
  68
  69                 /// <summary>
  70                 /// The view state key to ues for storing the value of the <see cref="XrdsAutoAnswer"/> property.
  71                 /// </summary>
  72                 private const string XrdsAutoAnswerViewStateKey = "XrdsAutoAnswer";
  73
  74                 /// <summary>
  75                 /// The default value for the <see cref="Enabled"/> property.
  76                 /// </summary>
  77                 private const bool EnabledDefault = true;
  78
  79                 /// <summary>
  80                 /// The view state key to ues for storing the value of the <see cref="Enabled"/> property.
  81                 /// </summary>
  82                 private const string EnabledViewStateKey = "Enabled";
  83
  84                 #region Properties
  85
  86                 /// <summary>
  87                 /// Gets or sets the location of the XRDS document.
  88                 /// </summary>
  89                 [SuppressMessage("Microsoft.Design", "CA1056:UriPropertiesShouldNotBeStrings", Justification = "Property grid")]
  90                 [SuppressMessage("Microsoft.Naming", "CA1704:IdentifiersShouldBeSpelledCorrectly", MessageId = "Xrds", Justification = "Correct spelling")]
  91                 [Category("Behavior"), Bindable(true)]
  92                 public string XrdsUrl {
  93                         get {
  94                                 return (string)ViewState[XrdsUrlViewStateKey];
  95                         }
  96
  97                         set {
  98                                 UriUtil.ValidateResolvableUrl(Page, DesignMode, value);
  99                                 ViewState[XrdsUrlViewStateKey] = value;
 100                         }
 101                 }
 102
 103                 /// <summary>
 104                 /// Gets or sets where the XRDS document URL is advertised in the web response.
 105                 /// </summary>
 106                 [SuppressMessage("Microsoft.Naming", "CA1704:IdentifiersShouldBeSpelledCorrectly", MessageId = "Xrds", Justification = "Correct spelling")]
 107                 [Category("Behavior"), DefaultValue(XrdsAdvertisementDefault), Bindable(true)]
 108                 [Description("Where the XRDS document URL is advertised in the web response.")]
 109                 public XrdsUrlLocations XrdsAdvertisement {
 110                         get {
 111                                 return ViewState[XrdsAdvertisementViewStateKey] == null ?
 112                                         XrdsAdvertisementDefault : (XrdsUrlLocations)ViewState[XrdsAdvertisementViewStateKey];
 113                         }
 114
 115                         set {
 116                                 ViewState[XrdsAdvertisementViewStateKey] = value;
 117                         }
 118                 }
 119
 120                 /// <summary>
 121                 /// Gets or sets a value indicating whether a specially crafted YADIS
 122                 /// search for an XRDS document is immediately answered by this control.
 123                 /// </summary>
 124                 [SuppressMessage("Microsoft.Naming", "CA1704:IdentifiersShouldBeSpelledCorrectly", MessageId = "Xrds", Justification = "Correct spelling")]
 125                 [Category("Behavior"), DefaultValue(XrdsAutoAnswerDefault), Bindable(true)]
 126                 [Description("Whether XRDS requests should be immediately answered with the XRDS document if it is served by this web application.")]
 127                 public bool XrdsAutoAnswer {
 128                         get {
 129                                 return ViewState[XrdsAutoAnswerViewStateKey] == null ?
 130                                         XrdsAutoAnswerDefault : (bool)ViewState[XrdsAutoAnswerViewStateKey];
 131                         }
 132
 133                         set {
 134                                 ViewState[XrdsAutoAnswerViewStateKey] = value;
 135                         }
 136                 }
 137
 138                 /// <summary>
 139                 /// Gets or sets a value indicating whether the XRDS document is advertised.
 140                 /// </summary>
 141                 [Category("Behavior"), DefaultValue(EnabledDefault)]
 142                 public bool Enabled {
 143                         get {
 144                                 return ViewState[EnabledViewStateKey] == null ?
 145                                 EnabledDefault : (bool)ViewState[EnabledViewStateKey];
 146                         }
 147
 148                         set {
 149                                 ViewState[EnabledViewStateKey] = value;
 150                         }
 151                 }
 152
 153                 #endregion
 154
 155                 /// <summary>
 156                 /// Detects YADIS requests for the XRDS document and responds immediately
 157                 /// if <see cref="XrdsAutoAnswer"/> is true.
 158                 /// </summary>
 159                 /// <param name="e">The <see cref="T:System.EventArgs"/> object that contains the event data.</param>
 160                 protected override void OnLoad(EventArgs e) {
 161                         base.OnLoad(e);
 162
 163                         if (!this.Enabled) {
 164                                 return;
 165                         }
 166
 167                         if (!this.Page.IsPostBack) {
 168                                 if (this.XrdsAutoAnswer && !string.IsNullOrEmpty(this.XrdsUrl) &&
 169                                         this.XrdsUrl.StartsWith("~/", StringComparison.Ordinal)) {
 170                                         // Check for the presence of an accept types header that is looking
 171                                         // for the XRDS document specifically.
 172                                         if (this.Page.Request.AcceptTypes != null && Array.IndexOf(this.Page.Request.AcceptTypes, ContentTypes.Xrds) >= 0) {
 173                                                 // Respond to the caller immediately with an XRDS document
 174                                                 // and avoid sending the whole web page's contents to the
 175                                                 // client since it isn't interested anyway.
 176                                                 // We do NOT simply send a 301 redirect here because that would
 177                                                 // alter the Claimed Identifier.
 178                                                 this.Page.Server.Transfer(this.XrdsUrl);
 179                                         }
 180                                 }
 181                         }
 182                 }
 183
 184                 /// <summary>
 185                 /// Renders the HTTP Header and/or HTML HEAD tags.
 186                 /// </summary>
 187                 /// <param name="writer">The <see cref="T:System.Web.UI.HtmlTextWriter"/> object that receives the server control content.</param>
 188                 protected override void Render(HtmlTextWriter writer) {
 189                         if (this.Enabled && this.Visible && !string.IsNullOrEmpty(this.XrdsUrl)) {
 190                                 Uri xrdsAddress = new Uri(MessagingUtilities.GetRequestUrlFromContext(), Page.Response.ApplyAppPathModifier(this.XrdsUrl));
 191                                 if ((this.XrdsAdvertisement & XrdsUrlLocations.HttpHeader) != 0) {
 192                                         Page.Response.AddHeader(Yadis.Yadis.HeaderName, xrdsAddress.AbsoluteUri);
 193                                 }
 194                                 if ((this.XrdsAdvertisement & XrdsUrlLocations.HtmlMeta) != 0) {
 195                                         writer.WriteBeginTag("meta");
 196                                         writer.WriteAttribute("http-equiv", Yadis.Yadis.HeaderName);
 197                                         writer.WriteAttribute("content", xrdsAddress.AbsoluteUri);
 198                                         writer.Write("/>");
 199                                         writer.WriteLine();
 200                                 }
 201                         }
 202                 }
 203         }
 204 }