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 \r
  12 using System;\r
  13 using System.Web;\r
  14 using System.Web.UI;\r
  15 using System.ComponentModel;
  16 using System.ComponentModel.Design;\r
  17 \r
  18 namespace System.Web.UI.WebControls\r
  19 {\r
  20         [DefaultEvent("Click")]\r
  21         [DefaultProperty("Text")]\r
  22         [ControlBuilder(typeof(LinkButtonControlBuilder))]\r
  23         [Designer("System.Web.UI.Design.WebControls.LinkButtonDesigner, " + Consts.AssemblySystem_Design, typeof (IDesigner))]\r
  24         [DataBindingHandler("System.Web.UI.Design.TextDataBindingHandler, " + Consts.AssemblySystem_Design)]\r
  25         [ParseChildren(false)]\r
  26         [ToolboxData("<{0}:LinkButton runat=\"server\">LinkButton</{0}:LinkButton>")]\r
  27         public class LinkButton : WebControl, IPostBackEventHandler\r
  28         {\r
  29                 private static readonly object ClickEvent   = new object();\r
  30                 private static readonly object CommandEvent = new object();\r
  31 \r
  32                 public LinkButton () : base (HtmlTextWriterTag.A)\r
  33                 {\r
  34                 }\r
  35
  36                 [DefaultValue (true), Bindable (false), WebCategory ("Behavior")]
  37                 [WebSysDescription ("Determines if validation is performed when clicked.")]\r
  38                 public bool CausesValidation\r
  39                 {\r
  40                         get {\r
  41                                 object o = ViewState ["CausesValidation"];\r
  42                                 return (o == null) ? true : (bool) o;\r
  43                         }\r
  44 \r
  45                         set { ViewState ["CausesValidation"] = value; }\r
  46                 }\r
  47
  48                 [DefaultValue (""), Bindable (true), WebCategory ("Behavior")]
  49                 [WebSysDescription ("An argument for the Command of this control.")]\r
  50                 public string CommandArgument\r
  51                 {\r
  52                         get {\r
  53                                 object o = ViewState ["CommandArgument"];\r
  54                                 return (o == null) ? String.Empty : (string) o;\r
  55                         }\r
  56 \r
  57                         set { ViewState ["CommandArgument"] = value; }\r
  58                 }\r
  59
  60                 [DefaultValue (""), WebCategory ("Behavior")]
  61                 [WebSysDescription ("The name of the Command of this control.")]\r
  62                 public string CommandName\r
  63                 {\r
  64                         get {\r
  65                                 object o = ViewState ["CommandName"];\r
  66                                 return (o == null) ? String.Empty : (string) o;\r
  67                         }\r
  68 \r
  69                         set { ViewState ["CommandName"] = value; }\r
  70                 }\r
  71
  72                 [DefaultValue (""), Bindable (true), WebCategory ("Appearance")]
  73                 [PersistenceMode (PersistenceMode.InnerDefaultProperty)]
  74                 [WebSysDescription ("The text that should be shown on this LinkButton.")]\r
  75                 public virtual string Text\r
  76                 {\r
  77                         get {\r
  78                                 object o = ViewState ["Text"];\r
  79                                 return (o == null) ? String.Empty : (string) o;\r
  80                         }\r
  81 \r
  82                         set { ViewState ["Text"] = value; }\r
  83                 }\r
  84
  85                 [WebCategory ("Action")]
  86                 [WebSysDescription ("Raised when the LinkButton is clicked.")]\r
  87                 public event EventHandler Click\r
  88                 {\r
  89                         add { Events.AddHandler(ClickEvent, value); }\r
  90                         remove { Events.RemoveHandler(ClickEvent, value); }\r
  91                 }\r
  92
  93                 [WebCategory ("Action")]
  94                 [WebSysDescription ("Raised when a LinkButton Command is executed.")]\r
  95                 public event CommandEventHandler Command\r
  96                 {\r
  97                         add { Events.AddHandler(CommandEvent, value); }\r
  98                         remove { Events.RemoveHandler(CommandEvent, value); }\r
  99                 }\r
 100 \r
 101                 protected virtual void OnClick (EventArgs e)\r
 102                 {\r
 103                         if(Events != null){\r
 104                                 EventHandler eh = (EventHandler) (Events [ClickEvent]);\r
 105                                 if (eh != null)\r
 106                                         eh (this, e);\r
 107                         }\r
 108                 }\r
 109 \r
 110                 protected virtual void OnCommand (CommandEventArgs e)\r
 111                 {\r
 112                         if(Events != null){\r
 113                                 CommandEventHandler ceh = (CommandEventHandler) (Events [CommandEvent]);\r
 114                                 if (ceh != null)\r
 115                                         ceh (this, e);\r
 116                         }\r
 117                         RaiseBubbleEvent (this, e);\r
 118                 }\r
 119 \r
 120                 protected override void OnPreRender (EventArgs e)\r
 121                 {\r
 122                         base.OnPreRender(e);\r
 123                 }\r
 124 \r
 125                 void IPostBackEventHandler.RaisePostBackEvent (string eventArgument)\r
 126                 {\r
 127                         if (CausesValidation)\r
 128                                 Page.Validate ();\r
 129                         OnClick (EventArgs.Empty);\r
 130                         OnCommand (new CommandEventArgs (CommandName, CommandArgument));\r
 131                 }\r
 132 \r
 133                 protected override void AddAttributesToRender (HtmlTextWriter writer)\r
 134                 {\r
 135                         base.AddAttributesToRender (writer);\r
 136                         if (Enabled && Page != null){\r
 137                                 if (CausesValidation && Page.Validators.Count > 0){\r
 138                                         writer.AddAttribute (HtmlTextWriterAttribute.Href,\r
 139                                                              "javascript:" + \r
 140                                                              Utils.GetClientValidatedPostBack (this));\r
 141                                         return;\r
 142                                 }\r
 143                                 writer.AddAttribute (HtmlTextWriterAttribute.Href,\r
 144                                                      Page.GetPostBackClientHyperlink (this, ""));\r
 145                         }\r
 146                 }\r
 147 \r
 148                 protected override void AddParsedSubObject (object obj)\r
 149                 {\r
 150                         if (HasControls ()){\r
 151                                 base.AddParsedSubObject (obj);\r
 152                                 return;\r
 153                         }\r
 154 \r
 155                         if (obj is LiteralControl){\r
 156                                 Text = ((LiteralControl) obj).Text;\r
 157                                 return;\r
 158                         }\r
 159 \r
 160                         if (Text.Length > 0){\r
 161                                 base.AddParsedSubObject (new LiteralControl (Text));\r
 162                                 Text = String.Empty;\r
 163                         }\r
 164 \r
 165                         base.AddParsedSubObject (obj);\r
 166                 }\r
 167 \r
 168                 protected override void LoadViewState (object savedState)\r
 169                 {\r
 170                         if (savedState != null){\r
 171                                 base.LoadViewState (savedState);\r
 172                                 string savedText = (string) ViewState ["Text"];\r
 173                                 if (savedText != null)\r
 174                                         Text = savedText;\r
 175                         }\r
 176                 }\r
 177 \r
 178                 protected override void RenderContents (HtmlTextWriter writer)\r
 179                 {\r
 180                         if (HasControls ()){\r
 181                                 base.RenderContents (writer);\r
 182                                 return;\r
 183                         }\r
 184                         writer.Write (Text);\r
 185                 }\r
 186         }\r
 187 }\r