mcs/class/System.Web/System.Web.UI/DataBinder.cs

   1 //
   2 // System.Web.UI.DataBinder.cs
   3 //
   4 // Authors:
   5 //      Duncan Mak  (duncan@ximian.com)
   6 //      Gonzalo Paniagua Javier (gonzalo@ximian.com)
   7 //
   8 // (C) 2002 Ximian, Inc. (http://www.ximian.com)
   9 //
  10
  11 //
  12 // Permission is hereby granted, free of charge, to any person obtaining
  13 // a copy of this software and associated documentation files (the
  14 // "Software"), to deal in the Software without restriction, including
  15 // without limitation the rights to use, copy, modify, merge, publish,
  16 // distribute, sublicense, and/or sell copies of the Software, and to
  17 // permit persons to whom the Software is furnished to do so, subject to
  18 // the following conditions:
  19 //
  20 // The above copyright notice and this permission notice shall be
  21 // included in all copies or substantial portions of the Software.
  22 //
  23 // THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
  24 // EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
  25 // MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
  26 // NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
  27 // LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
  28 // OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
  29 // WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
  30 //
  31
  32 using System;
  33 using System.Collections;
  34 using System.ComponentModel;
  35 using System.Reflection;
  36
  37 namespace System.Web.UI {
  38
  39         public sealed class DataBinder
  40         {
  41                 public DataBinder ()
  42                 {
  43                 }
  44
  45                 private static string FormatResult (object result, string format)
  46                 {
  47                         if (result == null)
  48                                 return String.Empty;
  49
  50                         if (format == null)
  51                                 return result.ToString ();
  52
  53                         return String.Format (format, result);
  54                 }
  55
  56                 public static object Eval (object container, string expression)
  57                 {
  58                         if (expression == null)
  59                                 throw new ArgumentNullException ("expression");
  60
  61                         object current = container;
  62
  63                         while (current != null) {
  64                                 int dot = expression.IndexOf ('.');
  65                                 int size = (dot == -1) ? expression.Length : dot;
  66                                 string prop = expression.Substring (0, size);
  67                                 if (prop.IndexOf ('[') != -1)
  68                                         current = GetIndexedPropertyValue (current, prop);
  69                                 else
  70                                         current = GetPropertyValue (current, prop);
  71
  72                                 if (dot == -1)
  73                                         break;
  74
  75                                 expression = expression.Substring (prop.Length + 1);
  76                         }
  77
  78                         return current;
  79                 }
  80
  81                 public static string Eval (object container, string expression, string format)
  82                 {
  83                         object result = Eval (container, expression);
  84                         return FormatResult (result, format);
  85                 }
  86
  87                 public static object GetIndexedPropertyValue (object container, string expr)
  88                 {
  89                         if (expr == null)
  90                                 throw new ArgumentNullException ("expr");
  91
  92                         int openIdx = expr.IndexOf ('[');
  93                         int closeIdx = expr.IndexOf (']'); // see the test case. MS ignores all after the first ]
  94                         if (openIdx < 0 || closeIdx < 0 || closeIdx - openIdx <= 1)
  95                                 throw new ArgumentException (expr + " is not a valid indexed expression.");
  96
  97                         string val = expr.Substring (openIdx + 1, closeIdx - openIdx - 1);
  98                         val = val.Trim ();
  99                         if (val.Length == 0)
 100                                 throw new ArgumentException (expr + " is not a valid indexed expression.");
 101
 102                         bool is_string = false;
 103                         // a quoted val means we have a string
 104                         if ((val[0] == '\'' && val[val.Length - 1] == '\'') ||
 105                                 (val[0] == '\"' && val[val.Length - 1] == '\"')) {
 106                                 is_string = true;
 107                                 val = val.Substring(1, val.Length - 2);
 108                         } else {
 109                                 // if all chars are digits, then we have a int
 110                                 for(int i = 0; i < val.Length; i++)
 111                                         if (!Char.IsDigit(val[i])) {
 112                                                 is_string = true;
 113                                                 break;
 114                                         }
 115                         }
 116
 117                         int intVal = 0;
 118                         if (!is_string) {
 119                                 try {
 120                                         intVal = Int32.Parse (val);
 121                                 } catch {
 122                                         throw new ArgumentException (expr + " is not a valid indexed expression.");
 123                                 }
 124                         }
 125
 126                         string property = null;
 127                         if (openIdx > 0) {
 128                                 property = expr.Substring (0, openIdx);
 129                                 if (property != null && property != String.Empty)
 130                                         container = GetPropertyValue (container, property);
 131                         }
 132
 133                         if (container == null)
 134                                 return null;
 135
 136                         if (container is System.Collections.IList) {
 137                                 IList l = (IList) container;
 138                                 return l [intVal];
 139                         }
 140
 141                         Type t = container.GetType ();
 142                         // MS does not seem to look for any other than "Item"!!!
 143                         object [] atts = t.GetCustomAttributes (typeof (DefaultMemberAttribute), false);
 144                         if (atts.Length != 1)
 145                                 throw new ArgumentException (expr + " indexer not found.");
 146
 147                         property = ((DefaultMemberAttribute) atts [0]).MemberName;
 148
 149                         Type [] argTypes = new Type [] { (is_string) ? typeof (string) : typeof (int) };
 150                         PropertyInfo prop = t.GetProperty (property, argTypes);
 151                         if (prop == null)
 152                                 throw new ArgumentException (expr + " indexer not found.");
 153
 154                         object [] args = new object [1];
 155                         if (is_string)
 156                                 args [0] = val;
 157                         else
 158                                 args [0] = intVal;
 159
 160                         return prop.GetValue (container, args);
 161                 }
 162
 163                 public static string GetIndexedPropertyValue (object container, string expr, string format)
 164                 {
 165                         object result = GetIndexedPropertyValue (container, expr);
 166                         return FormatResult (result, format);
 167                 }
 168
 169                 public static object GetPropertyValue (object container, string propName)
 170                 {
 171                         if (propName == null)
 172                                 throw new ArgumentNullException ("propName");
 173
 174                         PropertyDescriptor prop = TypeDescriptor.GetProperties (container).Find (propName, true);
 175                         if (prop == null) {
 176                                 throw new HttpException ("Property " + propName + " not found in " +
 177                                                          container.GetType ());
 178                         }
 179
 180                         return prop.GetValue (container);
 181                 }
 182
 183                 public static string GetPropertyValue (object container, string propName, string format)
 184                 {
 185                         object result = GetPropertyValue (container, propName);
 186                         return FormatResult (result, format);
 187                 }
 188
 189                 #if NET_2_0
 190                 public static object GetDataItem (object container, out bool foundDataItem)
 191                 {
 192                         foundDataItem = false;
 193                         if (container == null)
 194                                 return null;
 195
 196                         PropertyInfo pi = container.GetType ().GetProperty ("DataItem", BindingFlags.Public | BindingFlags.Instance);
 197                         if (pi == null)
 198                                 return null;
 199
 200                         foundDataItem = true;
 201                         return pi.GetValue (container, null);
 202                 }
 203
 204
 205                 public static object GetDataItem (object container)
 206                 {
 207                         bool flag;
 208                         return GetDataItem (container, out flag);
 209                 }
 210                 #endif
 211         }
 212 }
 213