mcs/class/System.Web.Mvc/System.Web.Mvc/ViewDataDictionary.cs

   1 /* ****************************************************************************\r
   2  *\r
   3  * Copyright (c) Microsoft Corporation. All rights reserved.\r
   4  *\r
   5  * This software is subject to the Microsoft Public License (Ms-PL). \r
   6  * A copy of the license can be found in the license.htm file included \r
   7  * in this distribution.\r
   8  *\r
   9  * You must not remove this notice, or any other, from this software.\r
  10  *\r
  11  * ***************************************************************************/\r
  12 \r
  13 namespace System.Web.Mvc {\r
  14     using System;\r
  15     using System.Collections;\r
  16     using System.Collections.Generic;\r
  17     using System.ComponentModel;\r
  18     using System.Diagnostics.CodeAnalysis;\r
  19     using System.Globalization;\r
  20     using System.Reflection;\r
  21     using System.Web.Mvc.Resources;\r
  22 \r
  23     // TODO: Unit test ModelState interaction with VDD\r
  24 \r
  25     public class ViewDataDictionary : IDictionary<string, object> {\r
  26 \r
  27         private readonly Dictionary<string, object> _innerDictionary = new Dictionary<string, object>(StringComparer.OrdinalIgnoreCase);\r
  28         private object _model;\r
  29         private readonly ModelStateDictionary _modelState = new ModelStateDictionary();\r
  30 \r
  31         public ViewDataDictionary()\r
  32             : this((object)null) {\r
  33         }\r
  34 \r
  35         [SuppressMessage("Microsoft.Usage", "CA2214:DoNotCallOverridableMethodsInConstructors",\r
  36             Justification = "See note on SetModel() method.")]\r
  37         public ViewDataDictionary(object model) {\r
  38             Model = model;\r
  39         }\r
  40 \r
  41         [SuppressMessage("Microsoft.Usage", "CA2214:DoNotCallOverridableMethodsInConstructors",\r
  42             Justification = "See note on SetModel() method.")]\r
  43         public ViewDataDictionary(ViewDataDictionary dictionary) {\r
  44             if (dictionary == null) {\r
  45                 throw new ArgumentNullException("dictionary");\r
  46             }\r
  47 \r
  48             foreach (var entry in dictionary) {\r
  49                 _innerDictionary.Add(entry.Key, entry.Value);\r
  50             }\r
  51             foreach (var entry in dictionary.ModelState) {\r
  52                 ModelState.Add(entry.Key, entry.Value);\r
  53             }\r
  54             Model = dictionary.Model;\r
  55         }\r
  56 \r
  57         [SuppressMessage("Microsoft.Security", "CA2123:OverrideLinkDemandsShouldBeIdenticalToBase")]\r
  58         public int Count {\r
  59             get {\r
  60                 return _innerDictionary.Count;\r
  61             }\r
  62         }\r
  63 \r
  64         [SuppressMessage("Microsoft.Security", "CA2123:OverrideLinkDemandsShouldBeIdenticalToBase")]\r
  65         public bool IsReadOnly {\r
  66             get {\r
  67                 return ((IDictionary<string, object>)_innerDictionary).IsReadOnly;\r
  68             }\r
  69         }\r
  70 \r
  71         [SuppressMessage("Microsoft.Security", "CA2123:OverrideLinkDemandsShouldBeIdenticalToBase")]\r
  72         public ICollection<string> Keys {\r
  73             get {\r
  74                 return _innerDictionary.Keys;\r
  75             }\r
  76         }\r
  77 \r
  78         public object Model {\r
  79             get {\r
  80                 return _model;\r
  81             }\r
  82             set {\r
  83                 SetModel(value);\r
  84             }\r
  85         }\r
  86 \r
  87         public ModelStateDictionary ModelState {\r
  88             get {\r
  89                 return _modelState;\r
  90             }\r
  91         }\r
  92 \r
  93         [SuppressMessage("Microsoft.Security", "CA2123:OverrideLinkDemandsShouldBeIdenticalToBase")]\r
  94         public object this[string key] {\r
  95             get {\r
  96                 object value;\r
  97                 _innerDictionary.TryGetValue(key, out value);\r
  98                 return value;\r
  99             }\r
 100             set {\r
 101                 _innerDictionary[key] = value;\r
 102             }\r
 103         }\r
 104 \r
 105         [SuppressMessage("Microsoft.Security", "CA2123:OverrideLinkDemandsShouldBeIdenticalToBase")]\r
 106         public ICollection<object> Values {\r
 107             get {\r
 108                 return _innerDictionary.Values;\r
 109             }\r
 110         }\r
 111 \r
 112         [SuppressMessage("Microsoft.Security", "CA2123:OverrideLinkDemandsShouldBeIdenticalToBase")]\r
 113         public void Add(KeyValuePair<string, object> item) {\r
 114             ((IDictionary<string, object>)_innerDictionary).Add(item);\r
 115         }\r
 116 \r
 117         [SuppressMessage("Microsoft.Security", "CA2123:OverrideLinkDemandsShouldBeIdenticalToBase")]\r
 118         public void Add(string key, object value) {\r
 119             _innerDictionary.Add(key, value);\r
 120         }\r
 121 \r
 122         [SuppressMessage("Microsoft.Security", "CA2123:OverrideLinkDemandsShouldBeIdenticalToBase")]\r
 123         public void Clear() {\r
 124             _innerDictionary.Clear();\r
 125         }\r
 126 \r
 127         [SuppressMessage("Microsoft.Security", "CA2123:OverrideLinkDemandsShouldBeIdenticalToBase")]\r
 128         public bool Contains(KeyValuePair<string, object> item) {\r
 129             return ((IDictionary<string, object>)_innerDictionary).Contains(item);\r
 130         }\r
 131 \r
 132         [SuppressMessage("Microsoft.Security", "CA2123:OverrideLinkDemandsShouldBeIdenticalToBase")]\r
 133         public bool ContainsKey(string key) {\r
 134             return _innerDictionary.ContainsKey(key);\r
 135         }\r
 136 \r
 137         [SuppressMessage("Microsoft.Security", "CA2123:OverrideLinkDemandsShouldBeIdenticalToBase")]\r
 138         public void CopyTo(KeyValuePair<string, object>[] array, int arrayIndex) {\r
 139             ((IDictionary<string, object>)_innerDictionary).CopyTo(array, arrayIndex);\r
 140         }\r
 141 \r
 142         [SuppressMessage("Microsoft.Naming", "CA1704:IdentifiersShouldBeSpelledCorrectly", MessageId = "Eval",\r
 143             Justification = "Commonly used shorthand for Evaluate.")]\r
 144         public object Eval(string expression) {\r
 145             if (String.IsNullOrEmpty(expression)) {\r
 146                 throw new ArgumentException(MvcResources.Common_NullOrEmpty, "expression");\r
 147             }\r
 148 \r
 149             return ViewDataEvaluator.Eval(this, expression);\r
 150         }\r
 151 \r
 152         [SuppressMessage("Microsoft.Naming", "CA1704:IdentifiersShouldBeSpelledCorrectly", MessageId = "Eval",\r
 153             Justification = "Commonly used shorthand for Evaluate.")]\r
 154         public string Eval(string expression, string format) {\r
 155             object value = Eval(expression);\r
 156 \r
 157             if (value == null) {\r
 158                 return String.Empty;\r
 159             }\r
 160 \r
 161             if (String.IsNullOrEmpty(format)) {\r
 162                 return Convert.ToString(value, CultureInfo.CurrentCulture);\r
 163             }\r
 164             else {\r
 165                 return String.Format(CultureInfo.CurrentCulture, format, value);\r
 166             }\r
 167         }\r
 168 \r
 169         [SuppressMessage("Microsoft.Security", "CA2123:OverrideLinkDemandsShouldBeIdenticalToBase")]\r
 170         public IEnumerator<KeyValuePair<string, object>> GetEnumerator() {\r
 171             return _innerDictionary.GetEnumerator();\r
 172         }\r
 173 \r
 174         [SuppressMessage("Microsoft.Security", "CA2123:OverrideLinkDemandsShouldBeIdenticalToBase")]\r
 175         public bool Remove(KeyValuePair<string, object> item) {\r
 176             return ((IDictionary<string, object>)_innerDictionary).Remove(item);\r
 177         }\r
 178 \r
 179         [SuppressMessage("Microsoft.Security", "CA2123:OverrideLinkDemandsShouldBeIdenticalToBase")]\r
 180         public bool Remove(string key) {\r
 181             return _innerDictionary.Remove(key);\r
 182         }\r
 183 \r
 184         // This method will execute before the derived type's instance constructor executes. Derived types must\r
 185         // be aware of this and should plan accordingly. For example, the logic in SetModel() should be simple\r
 186         // enough so as not to depend on the "this" pointer referencing a fully constructed object.\r
 187         protected virtual void SetModel(object value) {\r
 188             _model = value;\r
 189         }\r
 190 \r
 191         [SuppressMessage("Microsoft.Security", "CA2123:OverrideLinkDemandsShouldBeIdenticalToBase")]\r
 192         public bool TryGetValue(string key, out object value) {\r
 193             return _innerDictionary.TryGetValue(key, out value);\r
 194         }\r
 195 \r
 196         internal static class ViewDataEvaluator {\r
 197             public static object Eval(ViewDataDictionary vdd, string expression) {\r
 198                 //Given an expression "foo.bar.baz" we look up the following (pseudocode):\r
 199                 //  this["foo.bar.baz.quux"]\r
 200                 //  this["foo.bar.baz"]["quux"]\r
 201                 //  this["foo.bar"]["baz.quux]\r
 202                 //  this["foo.bar"]["baz"]["quux"]\r
 203                 //  this["foo"]["bar.baz.quux"]\r
 204                 //  this["foo"]["bar.baz"]["quux"]\r
 205                 //  this["foo"]["bar"]["baz.quux"]\r
 206                 //  this["foo"]["bar"]["baz"]["quux"]\r
 207 \r
 208                 object evaluated = EvalComplexExpression(vdd, expression);\r
 209                 return evaluated;\r
 210             }\r
 211 \r
 212             private static object EvalComplexExpression(object indexableObject, string expression) {\r
 213                 foreach (ExpressionPair expressionPair in GetRightToLeftExpressions(expression)) {\r
 214                     string subExpression = expressionPair.Left;\r
 215                     string postExpression = expressionPair.Right;\r
 216 \r
 217                     object subtarget = GetPropertyValue(indexableObject, subExpression);\r
 218                     if (subtarget != null) {\r
 219                         if (String.IsNullOrEmpty(postExpression))\r
 220                             return subtarget;\r
 221 \r
 222                         object potential = EvalComplexExpression(subtarget, postExpression);\r
 223                         if (potential != null) {\r
 224                             return potential;\r
 225                         }\r
 226                     }\r
 227                 }\r
 228                 return null;\r
 229             }\r
 230 \r
 231             private static IEnumerable<ExpressionPair> GetRightToLeftExpressions(string expression) {\r
 232                 // Produces an enumeration of all the combinations of complex property names\r
 233                 // given a complex expression. See the list above for an example of the result\r
 234                 // of the enumeration.\r
 235 \r
 236                 yield return new ExpressionPair(expression, String.Empty);\r
 237 \r
 238                 int lastDot = expression.LastIndexOf('.');\r
 239 \r
 240                 string subExpression = expression;\r
 241                 string postExpression = string.Empty;\r
 242 \r
 243                 while (lastDot > -1) {\r
 244                     subExpression = expression.Substring(0, lastDot);\r
 245                     postExpression = expression.Substring(lastDot + 1);\r
 246                     yield return new ExpressionPair(subExpression, postExpression);\r
 247 \r
 248                     lastDot = subExpression.LastIndexOf('.');\r
 249                 }\r
 250             }\r
 251 \r
 252             private static object GetIndexedPropertyValue(object indexableObject, string key) {\r
 253                 Type indexableType = indexableObject.GetType();\r
 254 \r
 255                 ViewDataDictionary vdd = indexableObject as ViewDataDictionary;\r
 256                 if (vdd != null) {\r
 257                     return vdd[key];\r
 258                 }\r
 259 \r
 260                 MethodInfo containsKeyMethod = indexableType.GetMethod("ContainsKey", BindingFlags.Public | BindingFlags.Instance, null, new Type[] { typeof(string) }, null);\r
 261                 if (containsKeyMethod != null) {\r
 262                     if (!(bool)containsKeyMethod.Invoke(indexableObject, new object[] { key })) {\r
 263                         return null;\r
 264                     }\r
 265                 }\r
 266 \r
 267                 PropertyInfo info = indexableType.GetProperty("Item", BindingFlags.Public | BindingFlags.Instance, null, null, new Type[] { typeof(string) }, null);\r
 268                 if (info != null) {\r
 269                     return info.GetValue(indexableObject, new object[] { key });\r
 270                 }\r
 271 \r
 272                 PropertyInfo objectInfo = indexableType.GetProperty("Item", BindingFlags.Public | BindingFlags.Instance, null, null, new Type[] { typeof(object) }, null);\r
 273                 if (objectInfo != null) {\r
 274                     return objectInfo.GetValue(indexableObject, new object[] { key });\r
 275                 }\r
 276                 return null;\r
 277             }\r
 278 \r
 279             private static object GetPropertyValue(object container, string propertyName) {\r
 280                 // This method handles one "segment" of a complex property expression\r
 281 \r
 282                 // First, we try to evaluate the property based on its indexer\r
 283                 object value = GetIndexedPropertyValue(container, propertyName);\r
 284                 if (value != null) {\r
 285                     return value;\r
 286                 }\r
 287 \r
 288                 // If the indexer didn't return anything useful, continue...\r
 289 \r
 290                 // If the container is a ViewDataDictionary then treat its Model property\r
 291                 // as the container instead of the ViewDataDictionary itself.\r
 292                 ViewDataDictionary vdd = container as ViewDataDictionary;\r
 293                 if (vdd != null) {\r
 294                     container = vdd.Model;\r
 295                 }\r
 296 \r
 297                 // Second, we try to use PropertyDescriptors and treat the expression as a property name\r
 298                 PropertyDescriptor descriptor = TypeDescriptor.GetProperties(container).Find(propertyName, true);\r
 299                 if (descriptor == null) {\r
 300                     return null;\r
 301                 }\r
 302 \r
 303                 return descriptor.GetValue(container);\r
 304             }\r
 305 \r
 306             private struct ExpressionPair {\r
 307                 public readonly string Left;\r
 308                 public readonly string Right;\r
 309 \r
 310                 public ExpressionPair(string left, string right) {\r
 311                     Left = left;\r
 312                     Right = right;\r
 313                 }\r
 314             }\r
 315         }\r
 316 \r
 317         #region IEnumerable Members\r
 318         [SuppressMessage("Microsoft.Security", "CA2123:OverrideLinkDemandsShouldBeIdenticalToBase")]\r
 319         IEnumerator IEnumerable.GetEnumerator() {\r
 320             return ((IEnumerable)_innerDictionary).GetEnumerator();\r
 321         }\r
 322         #endregion\r
 323 \r
 324     }\r
 325 }\r