mcs/class/System.Configuration/System.Configuration/ConfigurationProperty.cs

   1 //
   2 // System.Configuration.ConfigurationProperty.cs
   3 //
   4 // Authors:
   5 //      Duncan Mak (duncan@ximian.com)
   6 //  Lluis Sanchez Gual (lluis@novell.com)
   7 //
   8 // Permission is hereby granted, free of charge, to any person obtaining
   9 // a copy of this software and associated documentation files (the
  10 // "Software"), to deal in the Software without restriction, including
  11 // without limitation the rights to use, copy, modify, merge, publish,
  12 // distribute, sublicense, and/or sell copies of the Software, and to
  13 // permit persons to whom the Software is furnished to do so, subject to
  14 // the following conditions:
  15 //
  16 // The above copyright notice and this permission notice shall be
  17 // included in all copies or substantial portions of the Software.
  18 //
  19 // THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
  20 // EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
  21 // MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
  22 // NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
  23 // LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
  24 // OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
  25 // WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
  26 //
  27 // Copyright (C) 2004 Novell, Inc (http://www.novell.com)
  28 //
  29
  30 using System;
  31 using System.ComponentModel;
  32
  33 namespace System.Configuration
  34 {
  35         public sealed class ConfigurationProperty
  36         {
  37                 internal static readonly object NoDefaultValue = new object ();
  38
  39                 string name;
  40                 Type type;
  41                 object default_value;
  42                 TypeConverter converter;
  43                 ConfigurationValidatorBase validation;
  44                 ConfigurationPropertyOptions flags;
  45                 string description;
  46                 ConfigurationCollectionAttribute collectionAttribute;
  47
  48                 public ConfigurationProperty (string name, Type type)
  49                         : this (name, type, NoDefaultValue, TypeDescriptor.GetConverter (type), new DefaultValidator(), ConfigurationPropertyOptions.None, null)
  50                 { }
  51
  52                 public ConfigurationProperty (string name, Type type, object default_value)
  53                         : this (name, type, default_value, TypeDescriptor.GetConverter (type), new DefaultValidator(), ConfigurationPropertyOptions.None, null)
  54                 { }
  55
  56                 public ConfigurationProperty (
  57                                         string name, Type type, object default_value,
  58                                         ConfigurationPropertyOptions flags)
  59                         :this (name, type, default_value, TypeDescriptor.GetConverter (type), new DefaultValidator(), flags, null)
  60                 { }
  61
  62                 public ConfigurationProperty (
  63                                         string name, Type type, object default_value,
  64                                         TypeConverter converter,
  65                                         ConfigurationValidatorBase validation,
  66                                         ConfigurationPropertyOptions flags)
  67                         : this (name, type, default_value, converter, validation, flags, null)
  68                 { }
  69
  70                 public ConfigurationProperty (
  71                                         string name, Type type, object default_value,
  72                                         TypeConverter converter,
  73                                         ConfigurationValidatorBase validation,
  74                                         ConfigurationPropertyOptions flags,
  75                                         string description)
  76                 {
  77                         this.name = name;
  78                         this.converter = converter != null ? converter : TypeDescriptor.GetConverter (type);
  79                         if (default_value != null) {
  80                                 if (default_value == NoDefaultValue) {
  81                                         switch (Type.GetTypeCode (type)) {
  82                                         case TypeCode.Object:
  83                                                 default_value = null;
  84                                                 break;
  85                                         case TypeCode.String:
  86                                                 default_value = String.Empty;
  87                                                 break;
  88                                         default:
  89                                                 default_value = Activator.CreateInstance (type);
  90                                                 break;
  91                                         }
  92                                 }
  93                                 else
  94                                         if (!type.IsAssignableFrom (default_value.GetType ())) {
  95                                                 if (!this.converter.CanConvertFrom (default_value.GetType ()))
  96                                                         throw new ConfigurationErrorsException (String.Format ("The default value for property '{0}' has a different type than the one of the property itself: expected {1} but was {2}",
  97                                                                                                            name, type, default_value.GetType ()));
  98
  99                                                 default_value = this.converter.ConvertFrom (default_value);
 100                                         }
 101                         }
 102                         this.default_value = default_value;
 103                         this.flags = flags;
 104                         this.type = type;
 105                         this.validation = validation != null ? validation : new DefaultValidator ();
 106                         this.description = description;
 107                 }
 108
 109                 public TypeConverter Converter {
 110                         get { return converter; }
 111                 }
 112
 113                 public object DefaultValue {
 114                         get { return default_value; }
 115                 }
 116
 117                 public bool IsKey {
 118                         get { return (flags & ConfigurationPropertyOptions.IsKey) != 0; }
 119                 }
 120
 121                 public bool IsRequired {
 122                         get { return (flags & ConfigurationPropertyOptions.IsRequired) != 0; }
 123                 }
 124
 125                 public bool IsDefaultCollection {
 126                         get { return (flags & ConfigurationPropertyOptions.IsDefaultCollection) != 0; }
 127                 }
 128
 129                 public string Name {
 130                         get { return name; }
 131                 }
 132
 133                 public string Description {
 134                         get { return description; }
 135                 }
 136
 137                 public Type Type {
 138                         get { return type; }
 139                 }
 140
 141                 public ConfigurationValidatorBase Validator {
 142                         get { return validation; }
 143                 }
 144
 145                 internal object ConvertFromString (string value)
 146                 {
 147                         if (converter != null)
 148                                 return converter.ConvertFromInvariantString (value);
 149                         else
 150                                 throw new NotImplementedException ();
 151                 }
 152
 153                 internal string ConvertToString (object value)
 154                 {
 155                         if (converter != null)
 156                                 return converter.ConvertToInvariantString (value);
 157                         else
 158                                 throw new NotImplementedException ();
 159                 }
 160
 161                 internal bool IsElement {
 162                         get {
 163                                 return (typeof(ConfigurationElement).IsAssignableFrom (type));
 164                         }
 165                 }
 166
 167                 internal ConfigurationCollectionAttribute CollectionAttribute {
 168                         get { return collectionAttribute; }
 169                         set { collectionAttribute = value; }
 170                 }
 171
 172                 internal void Validate (object value)
 173                 {
 174                         if (validation != null)
 175                                 validation.Validate (value);
 176                 }
 177         }
 178 }
 179