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         [SuppressMessage("Microsoft.Naming", "CA1704:IdentifiersShouldBeSpelledCorrectly", MessageId = "Xrds", Justification = "Correct spelling")]
  47         [DefaultProperty("XrdsLocation")]
  48         [ToolboxData("<{0}:XrdsPublisher runat=server></{0}:XrdsPublisher>")]
  49         public class XrdsPublisher : Control {
  50                 /// <summary>
  51                 /// The view state key to ues for storing the value of the <see cref="XrdsUrl"/> property.
  52                 /// </summary>
  53                 private const string XrdsUrlViewStateKey = "XrdsUrl";
  54
  55                 /// <summary>
  56                 /// The default value for the <see cref="XrdsAdvertisement"/> property.
  57                 /// </summary>
  58                 private const XrdsUrlLocations XrdsAdvertisementDefault = XrdsUrlLocations.HttpHeader;
  59
  60                 /// <summary>
  61                 /// The view state key to ues for storing the value of the <see cref="XrdsAdvertisement"/> property.
  62                 /// </summary>
  63                 private const string XrdsAdvertisementViewStateKey = "XrdsAdvertisement";
  64
  65                 /// <summary>
  66                 /// The default value for the <see cref="XrdsAutoAnswer"/> property.
  67                 /// </summary>
  68                 private const bool XrdsAutoAnswerDefault = true;
  69
  70                 /// <summary>
  71                 /// The view state key to ues for storing the value of the <see cref="XrdsAutoAnswer"/> property.
  72                 /// </summary>
  73                 private const string XrdsAutoAnswerViewStateKey = "XrdsAutoAnswer";
  74
  75                 /// <summary>
  76                 /// The default value for the <see cref="Enabled"/> property.
  77                 /// </summary>
  78                 private const bool EnabledDefault = true;
  79
  80                 /// <summary>
  81                 /// The view state key to ues for storing the value of the <see cref="Enabled"/> property.
  82                 /// </summary>
  83                 private const string EnabledViewStateKey = "Enabled";
  84
  85                 #region Properties
  86
  87                 /// <summary>
  88                 /// Gets or sets the location of the XRDS document.
  89                 /// </summary>
  90                 [SuppressMessage("Microsoft.Design", "CA1056:UriPropertiesShouldNotBeStrings", Justification = "Property grid")]
  91                 [SuppressMessage("Microsoft.Naming", "CA1704:IdentifiersShouldBeSpelledCorrectly", MessageId = "Xrds", Justification = "Correct spelling")]
  92                 [Category("Behavior"), Bindable(true)]
  93                 public string XrdsUrl {
  94                         get {
  95                                 return (string)ViewState[XrdsUrlViewStateKey];
  96                         }
  97
  98                         set {
  99                                 UriUtil.ValidateResolvableUrl(Page, DesignMode, value);
 100                                 ViewState[XrdsUrlViewStateKey] = value;
 101                         }
 102                 }
 103
 104                 /// <summary>
 105                 /// Gets or sets where the XRDS document URL is advertised in the web response.
 106                 /// </summary>
 107                 [SuppressMessage("Microsoft.Naming", "CA1704:IdentifiersShouldBeSpelledCorrectly", MessageId = "Xrds", Justification = "Correct spelling")]
 108                 [Category("Behavior"), DefaultValue(XrdsAdvertisementDefault), Bindable(true)]
 109                 [Description("Where the XRDS document URL is advertised in the web response.")]
 110                 public XrdsUrlLocations XrdsAdvertisement {
 111                         get {
 112                                 return ViewState[XrdsAdvertisementViewStateKey] == null ?
 113                                         XrdsAdvertisementDefault : (XrdsUrlLocations)ViewState[XrdsAdvertisementViewStateKey];
 114                         }
 115
 116                         set {
 117                                 ViewState[XrdsAdvertisementViewStateKey] = value;
 118                         }
 119                 }
 120
 121                 /// <summary>
 122                 /// Gets or sets a value indicating whether a specially crafted YADIS
 123                 /// search for an XRDS document is immediately answered by this control.
 124                 /// </summary>
 125                 [SuppressMessage("Microsoft.Naming", "CA1704:IdentifiersShouldBeSpelledCorrectly", MessageId = "Xrds", Justification = "Correct spelling")]
 126                 [Category("Behavior"), DefaultValue(XrdsAutoAnswerDefault), Bindable(true)]
 127                 [Description("Whether XRDS requests should be immediately answered with the XRDS document if it is served by this web application.")]
 128                 public bool XrdsAutoAnswer {
 129                         get {
 130                                 return ViewState[XrdsAutoAnswerViewStateKey] == null ?
 131                                         XrdsAutoAnswerDefault : (bool)ViewState[XrdsAutoAnswerViewStateKey];
 132                         }
 133
 134                         set {
 135                                 ViewState[XrdsAutoAnswerViewStateKey] = value;
 136                         }
 137                 }
 138
 139                 /// <summary>
 140                 /// Gets or sets a value indicating whether the XRDS document is advertised.
 141                 /// </summary>
 142                 [Category("Behavior"), DefaultValue(EnabledDefault)]
 143                 public bool Enabled {
 144                         get {
 145                                 return ViewState[EnabledViewStateKey] == null ?
 146                                 EnabledDefault : (bool)ViewState[EnabledViewStateKey];
 147                         }
 148
 149                         set {
 150                                 ViewState[EnabledViewStateKey] = value;
 151                         }
 152                 }
 153
 154                 #endregion
 155
 156                 /// <summary>
 157                 /// Detects YADIS requests for the XRDS document and responds immediately
 158                 /// if <see cref="XrdsAutoAnswer"/> is true.
 159                 /// </summary>
 160                 /// <param name="e">The <see cref="T:System.EventArgs"/> object that contains the event data.</param>
 161                 protected override void OnLoad(EventArgs e) {
 162                         base.OnLoad(e);
 163
 164                         if (!this.Enabled) {
 165                                 return;
 166                         }
 167
 168                         if (!this.Page.IsPostBack) {
 169                                 if (this.XrdsAutoAnswer && !string.IsNullOrEmpty(this.XrdsUrl) &&
 170                                         this.XrdsUrl.StartsWith("~/", StringComparison.Ordinal)) {
 171                                         // Check for the presence of an accept types header that is looking
 172                                         // for the XRDS document specifically.
 173                                         if (this.Page.Request.AcceptTypes != null && Array.IndexOf(this.Page.Request.AcceptTypes, ContentTypes.Xrds) >= 0) {
 174                                                 // Respond to the caller immediately with an XRDS document
 175                                                 // and avoid sending the whole web page's contents to the
 176                                                 // client since it isn't interested anyway.
 177                                                 // We do NOT simply send a 301 redirect here because that would
 178                                                 // alter the Claimed Identifier.
 179                                                 this.Page.Server.Transfer(this.XrdsUrl);
 180                                         }
 181                                 }
 182                         }
 183                 }
 184
 185                 /// <summary>
 186                 /// Renders the HTTP Header and/or HTML HEAD tags.
 187                 /// </summary>
 188                 /// <param name="writer">The <see cref="T:System.Web.UI.HtmlTextWriter"/> object that receives the server control content.</param>
 189                 protected override void Render(HtmlTextWriter writer) {
 190                         if (this.Enabled && this.Visible && !string.IsNullOrEmpty(this.XrdsUrl)) {
 191                                 Uri xrdsAddress = new Uri(MessagingUtilities.GetRequestUrlFromContext(), Page.Response.ApplyAppPathModifier(this.XrdsUrl));
 192                                 if ((this.XrdsAdvertisement & XrdsUrlLocations.HttpHeader) != 0) {
 193                                         Page.Response.AddHeader(Yadis.Yadis.HeaderName, xrdsAddress.AbsoluteUri);
 194                                 }
 195                                 if ((this.XrdsAdvertisement & XrdsUrlLocations.HtmlMeta) != 0) {
 196                                         writer.WriteBeginTag("meta");
 197                                         writer.WriteAttribute("http-equiv", Yadis.Yadis.HeaderName);
 198                                         writer.WriteAttribute("content", xrdsAddress.AbsoluteUri);
 199                                         writer.Write("/>");
 200                                         writer.WriteLine();
 201                                 }
 202                         }
 203                 }
 204         }
 205 }