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

   1 /**\r
   2  * Namespace: System.Web.UI.WebControls\r
   3  * Class:     LinkButton\r
   4  *\r
   5  * Author:  Gaurav Vaish\r
   6  * Maintainer: gvaish@iitk.ac.in\r
   7  * Contact: <my_scripts2001@yahoo.com>, <gvaish@iitk.ac.in>\r
   8  * Implementation: yes\r
   9  * Status:  100%\r
  10  *\r
  11  * (C) Gaurav Vaish (2001)\r
  12  */\r
  13 \r
  14 using System;\r
  15 using System.Web;\r
  16 using System.Web.UI;\r
  17 \r
  18 namespace System.Web.UI.WebControls\r
  19 {\r
  20         [DefaultEvent("Click")]\r
  21         [DefaultProperty("Text")]\r
  22         //[Designer("??")]\r
  23         [ControlBuilder(typeof(LinkButtonControlBuilder))]\r
  24         //[DataBindingHandler("??")]\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 \r
  36                 public bool CausesValidation\r
  37                 {\r
  38                         get\r
  39                         {\r
  40                                 object o = ViewState["CausesValidation"];\r
  41                                 if(o!=null)\r
  42                                         return (bool)o;\r
  43                                 return true;\r
  44                         }\r
  45                         set\r
  46                         {\r
  47                                 ViewState["CausesValidation"] = value;\r
  48                         }\r
  49                 }\r
  50 \r
  51                 public string CommandArgument\r
  52                 {\r
  53                         get\r
  54                         {\r
  55                                 object o = ViewState["CommandArgument"];\r
  56                                 if(o!=null)\r
  57                                         return (string)o;\r
  58                                 return String.Empty;\r
  59                         }\r
  60                         set\r
  61                         {\r
  62                                 ViewState["CommandArgument"] = value;\r
  63                         }\r
  64                 }\r
  65 \r
  66                 public string CommandName\r
  67                 {\r
  68                         get\r
  69                         {\r
  70                                 object o = ViewState["CommandName"];\r
  71                                 if(o!=null)\r
  72                                         return (string)o;\r
  73                                 return String.Empty;\r
  74                         }\r
  75                         set\r
  76                         {\r
  77                                 ViewState["CommandName"] = value;\r
  78                         }\r
  79                 }\r
  80 \r
  81                 public virtual string Text\r
  82                 {\r
  83                         get\r
  84                         {\r
  85                                 object o = ViewState["Text"];\r
  86                                 if(o != null)\r
  87                                 {\r
  88                                         return (string)o;\r
  89                                 }\r
  90                                 return String.Empty;\r
  91                         }\r
  92                         set\r
  93                         {\r
  94                                 ViewState["Text"] = value;\r
  95                         }\r
  96                 }\r
  97 \r
  98                 public event EventHandler Click\r
  99                 {\r
 100                         add\r
 101                         {\r
 102                                 Events.AddHandler(ClickEvent, value);\r
 103                         }\r
 104                         remove\r
 105                         {\r
 106                                 Events.RemoveHandler(ClickEvent, value);\r
 107                         }\r
 108                 }\r
 109 \r
 110                 public event CommandEventHandler Command\r
 111                 {\r
 112                         add\r
 113                         {\r
 114                                 Events.AddHandler(CommandEvent, value);\r
 115                         }\r
 116                         remove\r
 117                         {\r
 118                                 Events.RemoveHandler(CommandEvent, value);\r
 119                         }\r
 120                 }\r
 121 \r
 122                 protected virtual void OnClick(EventArgs e)\r
 123                 {\r
 124                         if(Events != null)\r
 125                         {\r
 126                                 EventHandler eh = (EventHandler)(Events[ClickEvent]);\r
 127                                 if(eh != null)\r
 128                                         eh(this, e);\r
 129                         }\r
 130                 }\r
 131 \r
 132                 protected virtual void OnCommand(CommandEventArgs e)\r
 133                 {\r
 134                         if(Events != null)\r
 135                         {\r
 136                                 CommandEventHandler ceh = (CommandEventHandler)(Events[CommandEvent]);\r
 137                                 if(ceh != null)\r
 138                                         ceh(this, e);\r
 139                         }\r
 140                 }\r
 141 \r
 142                 void IPostBackEventHandler.RaisePostBackEvent(string eventArgument)\r
 143                 {\r
 144                         if(CausesValidation)\r
 145                         {\r
 146                                 Page.Validate();\r
 147                         }\r
 148                         OnClick(new EventArgs());\r
 149                         OnCommand( new CommandEventArgs(CommandName, CommandArgument));\r
 150                 }\r
 151 \r
 152                 protected override void AddAttributesToRender(HtmlTextWriter writer)\r
 153                 {\r
 154                         base.AddAttributesToRender(writer);\r
 155                         if(Enabled && Page != null)\r
 156                         {\r
 157                                 if(CausesValidation && Page.Validators.Count > 0)\r
 158                                 {\r
 159                                         writer.AddAttribute(HtmlTextWriterAttribute.Href, "javscript:" + Utils.GetClientValidatedPostBack(this));\r
 160                                         return;\r
 161                                 }\r
 162                                 writer.AddAttribute(HtmlTextWriterAttribute.Href, Page.GetPostBackClientHyperlink(this, ""));\r
 163                         }\r
 164                 }\r
 165 \r
 166                 protected override void AddParsedSubObject(object obj)\r
 167                 {\r
 168                         if(HasControls())\r
 169                         {\r
 170                                 AddParsedSubObject(obj);\r
 171                                 return;\r
 172                         }\r
 173                         if(obj is LiteralControl)\r
 174                         {\r
 175                                 Text = ((LiteralControl)obj).Text;\r
 176                                 return;\r
 177                         }\r
 178                         if(Text.Length > 0)\r
 179                         {\r
 180                                 AddParsedSubObject(Text);\r
 181                                 Text = String.Empty;\r
 182                         }\r
 183                         AddParsedSubObject(obj);\r
 184                 }\r
 185 \r
 186                 protected override void LoadViewState(object savedState)\r
 187                 {\r
 188                         if(savedState != null)\r
 189                         {\r
 190                                 base.LoadViewState(savedState);\r
 191                                 string savedText = (string)ViewState["Text"];\r
 192                                 if(savedText != null)\r
 193                                         Text = savedText;\r
 194                         }\r
 195                 }\r
 196 \r
 197                 protected override void RenderContents(HtmlTextWriter writer)\r
 198                 {\r
 199                         if(HasControls())\r
 200                         {\r
 201                                 RenderContents(writer);\r
 202                                 return;\r
 203                         }\r
 204                         writer.Write(Text);\r
 205                 }\r
 206         }\r
 207 }\r