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

   1 //
   2 // System.Web.UI.WebControls.Parameter
   3 //
   4 // Authors:
   5 //      Ben Maurer (bmaurer@users.sourceforge.net)
   6 //      Sanjay Gupta (gsanjay@novell.com)
   7 //
   8 // (C) 2003 Ben Maurer
   9 // (C) 2004 Novell, Inc. (http://www.novell.com)
  10 //
  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
  33 #if NET_2_0
  34 using System.Collections;
  35 using System.Collections.Specialized;
  36 using System.Text;
  37 using System.Data;
  38 using System.ComponentModel;
  39
  40 namespace System.Web.UI.WebControls {
  41         [DefaultPropertyAttribute ("DefaultValue")]
  42         public class Parameter : ICloneable, IStateManager {
  43
  44                 public Parameter () : base ()
  45                 {
  46                 }
  47
  48                 protected Parameter (Parameter original)
  49                 {
  50                         this.DefaultValue = original.DefaultValue;
  51                         this.Direction = original.Direction;
  52                         this.ConvertEmptyStringToNull = original.ConvertEmptyStringToNull;
  53                         this.Type = original.Type;
  54                         this.Name = original.Name;
  55                 }
  56
  57                 public Parameter (string name)
  58                 {
  59                         this.Name = name;
  60                 }
  61
  62                 public Parameter(string name, TypeCode type) : this (name)
  63                 {
  64                         this.Type = type;
  65                 }
  66
  67                 public Parameter (string name, TypeCode type, string defaultValue) : this (name, type)
  68                 {
  69                         this.DefaultValue = defaultValue;
  70                 }
  71
  72                 protected virtual Parameter Clone ()
  73                 {
  74                         return new Parameter (this);
  75                 }
  76
  77                 protected void OnParameterChanged ()
  78                 {
  79                         if (_owner != null)
  80                                 _owner.CallOnParameterChanged ();
  81                 }
  82
  83                 protected virtual void LoadViewState (object savedState)
  84                 {
  85                         ViewState.LoadViewState (savedState);
  86                 }
  87
  88                 protected virtual object SaveViewState ()
  89                 {
  90                         return ViewState.SaveViewState ();
  91                 }
  92
  93                 protected virtual void TrackViewState ()
  94                 {
  95                         isTrackingViewState = true;
  96                         if (viewState != null)
  97                                 viewState.TrackViewState ();
  98                 }
  99
 100                 object ICloneable.Clone ()
 101                 {
 102                         return this.Clone ();
 103                 }
 104
 105                 void IStateManager.LoadViewState (object savedState)
 106                 {
 107                         this.LoadViewState (savedState);
 108                 }
 109
 110                 object IStateManager.SaveViewState ()
 111                 {
 112                         return this.SaveViewState ();
 113                 }
 114
 115                 void IStateManager.TrackViewState ()
 116                 {
 117                         this.TrackViewState ();
 118                 }
 119
 120                 bool IStateManager.IsTrackingViewState {
 121                         get { return this.IsTrackingViewState; }
 122                 }
 123
 124                 public override string ToString ()
 125                 {
 126                         object o = GetValue (HttpContext.Current, null);
 127                         if (o != null) return o.ToString();
 128                         return "";
 129                 }
 130
 131                 [WebCategoryAttribute ("Parameter")]
 132                 [DefaultValueAttribute (null)]
 133                 [WebSysDescriptionAttribute ("Default value to be used in case value is null.")]
 134                 public string DefaultValue {
 135                         get { return ViewState.GetString ("DefaultValue", null); }
 136                         set {
 137
 138                                 if (DefaultValue != value) {
 139                                         ViewState ["DefaultValue"] = value;
 140                                         OnParameterChanged ();
 141                                 }
 142                         }
 143                 }
 144
 145                 [WebCategoryAttribute ("Parameter")]
 146                 [DefaultValueAttribute ("Input")]
 147                 [WebSysDescriptionAttribute ("Parameter's direction.")]
 148                 public ParameterDirection Direction
 149                 {
 150                         get { return (ParameterDirection) ViewState.GetInt ("Direction", (int)ParameterDirection.Input); }
 151                         set {
 152                                 if (Direction != value) {
 153                                         ViewState ["Direction"] = value;
 154                                         OnParameterChanged ();
 155                                 }
 156                         }
 157                 }
 158
 159
 160                 [WebCategoryAttribute ("Parameter")]
 161                 [DefaultValueAttribute ("")]
 162                 [WebSysDescriptionAttribute ("Parameter's name.")]
 163                 public string Name
 164                 {
 165                         get {
 166                                 string s = ViewState ["Name"] as string;
 167                                 if (s != null)
 168                                         return s;
 169
 170                                 return "";
 171                         }
 172                         set {
 173
 174                                 if (Name != value) {
 175                                         ViewState ["Name"] = value;
 176                                         OnParameterChanged ();
 177                                 }
 178                         }
 179                 }
 180
 181                 [WebCategoryAttribute ("Parameter")]
 182                 [DefaultValueAttribute (true)]
 183                 [WebSysDescriptionAttribute ("Checks whether an empty string is treated as a null value.")]
 184                 public bool ConvertEmptyStringToNull
 185                 {
 186                         get { return ViewState.GetBool ("ConvertEmptyStringToNull", true); }
 187                         set {
 188                                 if (ConvertEmptyStringToNull != value) {
 189                                         ViewState["ConvertEmptyStringToNull"] = value;
 190                                         OnParameterChanged ();
 191                                 }
 192                         }
 193                 }
 194
 195                 [DefaultValue (0)]
 196                 public int Size {
 197                         get { return ViewState.GetInt ("Size", 0); }
 198                         set {
 199                                 if (Size != value) {
 200                                         ViewState["Size"] = value;
 201                                         OnParameterChanged ();
 202                                 }
 203                         }
 204                 }
 205
 206                 [DefaultValueAttribute (TypeCode.Empty)]
 207                 [WebCategoryAttribute ("Parameter"),
 208                 WebSysDescriptionAttribute("Represents type of the parameter.")]
 209                 public TypeCode Type
 210                 {
 211                         get { return (TypeCode) ViewState.GetInt ("Type", (int)TypeCode.Empty); }
 212                         set {
 213
 214                                 if (Type != value) {
 215                                         ViewState ["Type"] = value;
 216                                         OnParameterChanged ();
 217                                 }
 218                         }
 219                 }
 220
 221                 StateBag viewState;
 222                 [BrowsableAttribute (false),
 223                 DesignerSerializationVisibilityAttribute (DesignerSerializationVisibility.Hidden)]
 224                 protected StateBag ViewState {
 225                         get {
 226                                 if (viewState == null) {
 227                                         viewState = new StateBag ();
 228                                         if (IsTrackingViewState)
 229                                                 viewState.TrackViewState ();
 230                                 }
 231                                 return viewState;
 232                         }
 233                 }
 234
 235                 bool isTrackingViewState = false;
 236                 protected bool IsTrackingViewState {
 237                         get { return isTrackingViewState; }
 238                 }
 239
 240                 protected virtual object Evaluate (HttpContext context, Control control)
 241                 {
 242                         return this.DefaultValue;
 243                 }
 244
 245                 internal object GetValue (HttpContext context, Control control)
 246                 {
 247                         object oldValue = ViewState ["ParameterValue"];
 248
 249                         object newValue = ConvertValue (Evaluate (context, control));
 250                         if (newValue == null)
 251                                 newValue = ConvertValue (DefaultValue);
 252
 253                         if (!object.Equals (oldValue, newValue)) {
 254                                 ViewState ["ParameterValue"] = newValue;
 255                                 OnParameterChanged ();
 256                         }
 257                         return newValue;
 258                 }
 259
 260                 object ConvertValue (object val)
 261                 {
 262                         if (val == null) return null;
 263                         if (ConvertEmptyStringToNull && val.Equals (string.Empty))
 264                                 return null;
 265                         return Convert.ChangeType (val, Type);
 266                 }
 267
 268                 protected internal virtual void SetDirty()
 269                 {
 270                         ViewState.SetDirty (true);
 271                 }
 272
 273
 274                 private ParameterCollection _owner;
 275
 276                 internal void SetOwnerCollection (ParameterCollection own)
 277                 {
 278                         _owner = own;
 279                 }
 280         }
 281 }
 282 #endif
 283