mcs/class/System.Web/System.Web.UI.WebControls/LinkButton.cs

   1 //
   2 // System.Web.UI.WebControls.LinkButton.cs
   3 //
   4 // Authors:
   5 //   Gaurav Vaish (gvaish@iitk.ac.in)
   6 //   Andreas Nahr (ClassDevelopment@A-SoftTech.com)
   7 //
   8 // (C) Gaurav Vaish (2002)
   9 // (C) 2003 Andreas Nahr
  10 //\r
  11
  12 //
  13 // Permission is hereby granted, free of charge, to any person obtaining
  14 // a copy of this software and associated documentation files (the
  15 // "Software"), to deal in the Software without restriction, including
  16 // without limitation the rights to use, copy, modify, merge, publish,
  17 // distribute, sublicense, and/or sell copies of the Software, and to
  18 // permit persons to whom the Software is furnished to do so, subject to
  19 // the following conditions:
  20 //
  21 // The above copyright notice and this permission notice shall be
  22 // included in all copies or substantial portions of the Software.
  23 //
  24 // THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
  25 // EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
  26 // MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
  27 // NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
  28 // LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
  29 // OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
  30 // WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
  31 //
  32 \r
  33 using System;\r
  34 using System.Web;\r
  35 using System.Web.UI;\r
  36 using System.ComponentModel;
  37 using System.ComponentModel.Design;\r
  38 \r
  39 namespace System.Web.UI.WebControls\r
  40 {\r
  41         [DefaultEvent("Click")]\r
  42         [DefaultProperty("Text")]\r
  43         [ControlBuilder(typeof(LinkButtonControlBuilder))]\r
  44         [Designer("System.Web.UI.Design.WebControls.LinkButtonDesigner, " + Consts.AssemblySystem_Design, typeof (IDesigner))]\r
  45         [DataBindingHandler("System.Web.UI.Design.TextDataBindingHandler, " + Consts.AssemblySystem_Design)]\r
  46         [ParseChildren(false)]\r
  47         [ToolboxData("<{0}:LinkButton runat=\"server\">LinkButton</{0}:LinkButton>")]\r
  48         public class LinkButton : WebControl, IPostBackEventHandler\r
  49         {\r
  50                 private static readonly object ClickEvent   = new object();\r
  51                 private static readonly object CommandEvent = new object();\r
  52 \r
  53                 public LinkButton () : base (HtmlTextWriterTag.A)\r
  54                 {\r
  55                 }\r
  56
  57                 [DefaultValue (true), Bindable (false), WebCategory ("Behavior")]
  58                 [WebSysDescription ("Determines if validation is performed when clicked.")]\r
  59                 public bool CausesValidation\r
  60                 {\r
  61                         get {\r
  62                                 object o = ViewState ["CausesValidation"];\r
  63                                 return (o == null) ? true : (bool) o;\r
  64                         }\r
  65 \r
  66                         set { ViewState ["CausesValidation"] = value; }\r
  67                 }\r
  68
  69                 [DefaultValue (""), Bindable (true), WebCategory ("Behavior")]
  70                 [WebSysDescription ("An argument for the Command of this control.")]\r
  71                 public string CommandArgument\r
  72                 {\r
  73                         get {\r
  74                                 object o = ViewState ["CommandArgument"];\r
  75                                 return (o == null) ? String.Empty : (string) o;\r
  76                         }\r
  77 \r
  78                         set { ViewState ["CommandArgument"] = value; }\r
  79                 }\r
  80
  81                 [DefaultValue (""), WebCategory ("Behavior")]
  82                 [WebSysDescription ("The name of the Command of this control.")]\r
  83                 public string CommandName\r
  84                 {\r
  85                         get {\r
  86                                 object o = ViewState ["CommandName"];\r
  87                                 return (o == null) ? String.Empty : (string) o;\r
  88                         }\r
  89 \r
  90                         set { ViewState ["CommandName"] = value; }\r
  91                 }\r
  92
  93                 [DefaultValue (""), Bindable (true), WebCategory ("Appearance")]
  94                 [PersistenceMode (PersistenceMode.InnerDefaultProperty)]
  95                 [WebSysDescription ("The text that should be shown on this LinkButton.")]\r
  96                 public virtual string Text\r
  97                 {\r
  98                         get {\r
  99                                 object o = ViewState ["Text"];\r
 100                                 return (o == null) ? String.Empty : (string) o;\r
 101                         }\r
 102 \r
 103                         set { ViewState ["Text"] = value; }\r
 104                 }\r
 105
 106                 [WebCategory ("Action")]
 107                 [WebSysDescription ("Raised when the LinkButton is clicked.")]\r
 108                 public event EventHandler Click\r
 109                 {\r
 110                         add { Events.AddHandler(ClickEvent, value); }\r
 111                         remove { Events.RemoveHandler(ClickEvent, value); }\r
 112                 }\r
 113
 114                 [WebCategory ("Action")]
 115                 [WebSysDescription ("Raised when a LinkButton Command is executed.")]\r
 116                 public event CommandEventHandler Command\r
 117                 {\r
 118                         add { Events.AddHandler(CommandEvent, value); }\r
 119                         remove { Events.RemoveHandler(CommandEvent, value); }\r
 120                 }\r
 121 \r
 122                 protected virtual void OnClick (EventArgs e)\r
 123                 {\r
 124                         if(Events != null){\r
 125                                 EventHandler eh = (EventHandler) (Events [ClickEvent]);\r
 126                                 if (eh != null)\r
 127                                         eh (this, e);\r
 128                         }\r
 129                 }\r
 130 \r
 131                 protected virtual void OnCommand (CommandEventArgs e)\r
 132                 {\r
 133                         if(Events != null){\r
 134                                 CommandEventHandler ceh = (CommandEventHandler) (Events [CommandEvent]);\r
 135                                 if (ceh != null)\r
 136                                         ceh (this, e);\r
 137                         }\r
 138                         RaiseBubbleEvent (this, e);\r
 139                 }\r
 140 \r
 141                 protected override void OnPreRender (EventArgs e)\r
 142                 {\r
 143                         base.OnPreRender(e);\r
 144                 }\r
 145 \r
 146                 void IPostBackEventHandler.RaisePostBackEvent (string eventArgument)\r
 147                 {\r
 148                         if (CausesValidation)\r
 149                                 Page.Validate ();\r
 150                         OnClick (EventArgs.Empty);\r
 151                         OnCommand (new CommandEventArgs (CommandName, CommandArgument));\r
 152                 }\r
 153 \r
 154                 protected override void AddAttributesToRender (HtmlTextWriter writer)\r
 155                 {\r
 156                         base.AddAttributesToRender (writer);\r
 157                         if (Enabled && Page != null){\r
 158                                 if (CausesValidation && Page.Validators.Count > 0){\r
 159                                         writer.AddAttribute (HtmlTextWriterAttribute.Href,\r
 160                                                              "javascript:" + \r
 161                                                              Utils.GetClientValidatedPostBack (this));\r
 162                                         return;\r
 163                                 }\r
 164                                 writer.AddAttribute (HtmlTextWriterAttribute.Href,\r
 165                                                      Page.GetPostBackClientHyperlink (this, ""));\r
 166                         }\r
 167                 }\r
 168 \r
 169                 protected override void AddParsedSubObject (object obj)\r
 170                 {\r
 171                         if (HasControls ()){\r
 172                                 base.AddParsedSubObject (obj);\r
 173                                 return;\r
 174                         }\r
 175 \r
 176                         if (obj is LiteralControl){\r
 177                                 Text = ((LiteralControl) obj).Text;\r
 178                                 return;\r
 179                         }\r
 180 \r
 181                         if (Text.Length > 0){\r
 182                                 base.AddParsedSubObject (new LiteralControl (Text));\r
 183                                 Text = String.Empty;\r
 184                         }\r
 185 \r
 186                         base.AddParsedSubObject (obj);\r
 187                 }\r
 188 \r
 189                 protected override void LoadViewState (object savedState)\r
 190                 {\r
 191                         if (savedState != null){\r
 192                                 base.LoadViewState (savedState);\r
 193                                 string savedText = (string) ViewState ["Text"];\r
 194                                 if (savedText != null)\r
 195                                         Text = savedText;\r
 196                         }\r
 197                 }\r
 198 \r
 199                 protected override void RenderContents (HtmlTextWriter writer)\r
 200                 {\r
 201                         if (HasControls ()){\r
 202                                 base.RenderContents (writer);\r
 203                                 return;\r
 204                         }\r
 205                         writer.Write (Text);\r
 206                 }\r
 207         }\r
 208 }\r