mcs/class/System.Web/System.Web.UI.HtmlControls/HtmlInputHidden.cs

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   4 // "Software"), to deal in the Software without restriction, including
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   7 // permit persons to whom the Software is furnished to do so, subject to
   8 // the following conditions:
   9 //
  10 // The above copyright notice and this permission notice shall be
  11 // included in all copies or substantial portions of the Software.
  12 //
  13 // THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
  14 // EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
  15 // MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
  16 // NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
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  19 // WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
  20 //
  21 //
  22 // System.Web.UI.HtmlControls.HtmlInputHidden.cs
  23 //
  24 // Authors:
  25 //      Jackson Harper (jackson@ximian.com)
  26 //
  27 // (C) 2005-2010 Novell, Inc.
  28
  29 using System.ComponentModel;
  30 using System.Collections.Specialized;
  31 using System.Security.Permissions;
  32
  33 namespace System.Web.UI.HtmlControls {
  34
  35         // CAS
  36         [AspNetHostingPermission (SecurityAction.LinkDemand, Level = AspNetHostingPermissionLevel.Minimal)]
  37         [AspNetHostingPermission (SecurityAction.InheritanceDemand, Level = AspNetHostingPermissionLevel.Minimal)]
  38         // attributes
  39         [DefaultEvent ("ServerChange")]
  40         [SupportsEventValidation]
  41         public class HtmlInputHidden : HtmlInputControl, IPostBackDataHandler {
  42
  43                 static readonly object ServerChangeEvent = new object ();
  44
  45                 public HtmlInputHidden () : base ("hidden")
  46                 {
  47                 }
  48
  49                 bool LoadPostDataInternal (string postDataKey, NameValueCollection postCollection)
  50                 {
  51                         string data = postCollection [postDataKey];
  52                         if (data != null && data != Value) {
  53                                 ValidateEvent (postDataKey, String.Empty);
  54                                 Value = data;
  55                                 return true;
  56                         }
  57                         return false;
  58                 }
  59
  60                 void RaisePostDataChangedEventInternal ()
  61                 {
  62                         OnServerChange (EventArgs.Empty);
  63                 }
  64
  65                 protected virtual bool LoadPostData (string postDataKey, NameValueCollection postCollection)
  66                 {
  67                         return LoadPostDataInternal (postDataKey, postCollection);
  68                 }
  69
  70                 protected virtual void RaisePostDataChangedEvent ()
  71                 {
  72                         RaisePostDataChangedEventInternal ();
  73                 }
  74
  75                 bool IPostBackDataHandler.LoadPostData (string postDataKey,
  76                                                         NameValueCollection postCollection)
  77                 {
  78                         return LoadPostData (postDataKey, postCollection);
  79                 }
  80
  81                 void IPostBackDataHandler.RaisePostDataChangedEvent ()
  82                 {
  83                         RaisePostDataChangedEvent ();
  84                 }
  85
  86                 protected override void RenderAttributes (HtmlTextWriter writer)
  87                 {
  88                         Page page = Page;
  89                         if (page != null)
  90                                 page.ClientScript.RegisterForEventValidation (Name);
  91                         base.RenderAttributes (writer);
  92                 }
  93
  94                 protected internal override void OnPreRender (EventArgs e)
  95                 {
  96                         base.OnPreRender (e);
  97
  98                         Page page = Page;
  99                         if (page != null && !Disabled) {
 100                                 page.RegisterRequiresPostBack (this);
 101                                 page.RegisterEnabledControl (this);
 102                         }
 103                 }
 104
 105                 protected virtual void OnServerChange (EventArgs e)
 106                 {
 107                         EventHandler handler = (EventHandler) Events [ServerChangeEvent];
 108                         if (handler != null)
 109                                 handler (this, e);
 110                 }
 111
 112                 [WebSysDescription("")]
 113                 [WebCategory("Action")]
 114                 public event EventHandler ServerChange {
 115                         add { Events.AddHandler (ServerChangeEvent, value); }
 116                         remove { Events.RemoveHandler (ServerChangeEvent, value); }
 117                 }
 118         }
 119 }