For those who don't want to go for Newtonsoft Json.Net or DataContractJsonSerializer for some reason (I can't think of any :) ), here is an implementation of JavaScriptConverter that supports DataContract and enum to string conversion -
public class DataContractJavaScriptConverter : JavaScriptConverter
{
private static readonly List<Type> _supportedTypes = new List<Type>();
static DataContractJavaScriptConverter()
{
foreach (Type type in Assembly.GetExecutingAssembly().DefinedTypes)
{
if (Attribute.IsDefined(type, typeof(DataContractAttribute)))
{
_supportedTypes.Add(type);
}
}
}
private bool ConvertEnumToString = false;
public DataContractJavaScriptConverter() : this(false)
{
}
public DataContractJavaScriptConverter(bool convertEnumToString)
{
ConvertEnumToString = convertEnumToString;
}
public override IEnumerable<Type> SupportedTypes
{
get { return _supportedTypes; }
}
public override object Deserialize(IDictionary<string, object> dictionary, Type type, JavaScriptSerializer serializer)
{
if (Attribute.IsDefined(type, typeof(DataContractAttribute)))
{
try
{
object instance = Activator.CreateInstance(type);
IEnumerable<MemberInfo> members = ((IEnumerable<MemberInfo>)type.GetFields())
.Concat(type.GetProperties().Where(property => property.CanWrite && property.GetIndexParameters().Length == 0))
.Where((member) => Attribute.IsDefined(member, typeof(DataMemberAttribute)));
foreach (MemberInfo member in members)
{
DataMemberAttribute attribute = (DataMemberAttribute)Attribute.GetCustomAttribute(member, typeof(DataMemberAttribute));
object value;
if (dictionary.TryGetValue(attribute.Name, out value) == false)
{
if (attribute.IsRequired)
{
throw new SerializationException(String.Format("Required DataMember with name {0} not found", attribute.Name));
}
continue;
}
if (member.MemberType == MemberTypes.Field)
{
FieldInfo field = (FieldInfo)member;
object fieldValue;
if (ConvertEnumToString && field.FieldType.IsEnum)
{
fieldValue = Enum.Parse(field.FieldType, value.ToString());
}
else
{
fieldValue = serializer.ConvertToType(value, field.FieldType);
}
field.SetValue(instance, fieldValue);
}
else if (member.MemberType == MemberTypes.Property)
{
PropertyInfo property = (PropertyInfo)member;
object propertyValue;
if (ConvertEnumToString && property.PropertyType.IsEnum)
{
propertyValue = Enum.Parse(property.PropertyType, value.ToString());
}
else
{
propertyValue = serializer.ConvertToType(value, property.PropertyType);
}
property.SetValue(instance, propertyValue);
}
}
return instance;
}
catch (Exception)
{
return null;
}
}
return null;
}
public override IDictionary<string, object> Serialize(object obj, JavaScriptSerializer serializer)
{
Dictionary<string, object> dictionary = new Dictionary<string, object>();
if (obj != null && Attribute.IsDefined(obj.GetType(), typeof(DataContractAttribute)))
{
Type type = obj.GetType();
IEnumerable<MemberInfo> members = ((IEnumerable<MemberInfo>)type.GetFields())
.Concat(type.GetProperties().Where(property => property.CanRead && property.GetIndexParameters().Length == 0))
.Where((member) => Attribute.IsDefined(member, typeof(DataMemberAttribute)));
foreach (MemberInfo member in members)
{
DataMemberAttribute attribute = (DataMemberAttribute)Attribute.GetCustomAttribute(member, typeof(DataMemberAttribute));
object value;
if (member.MemberType == MemberTypes.Field)
{
FieldInfo field = (FieldInfo)member;
if (ConvertEnumToString && field.FieldType.IsEnum)
{
value = field.GetValue(obj).ToString();
}
else
{
value = field.GetValue(obj);
}
}
else if (member.MemberType == MemberTypes.Property)
{
PropertyInfo property = (PropertyInfo)member;
if (ConvertEnumToString && property.PropertyType.IsEnum)
{
value = property.GetValue(obj).ToString();
}
else
{
value = property.GetValue(obj);
}
}
else
{
continue;
}
if (dictionary.ContainsKey(attribute.Name))
{
throw new SerializationException(String.Format("More than one DataMember found with name {0}", attribute.Name));
}
dictionary[attribute.Name] = value;
}
}
return dictionary;
}
}
Note: This DataContractJavaScriptConverter will only handle DataContract classes defined in the assembly where it is placed. If you want classes from separate assemblies, modify the _supportedTypes list accordingly in the static constructror.
This can be used as follows -
JavaScriptSerializer serializer = new JavaScriptSerializer();
serializer.RegisterConverters(new JavaScriptConverter[] { new DataContractJavaScriptConverter(true) });
DataObject dataObject = serializer.Deserialize<DataObject>(JsonData);
The DataObject class would look like this -
using System.Runtime.Serialization;
[DataContract]
public class DataObject
{
[DataMember(Name = "user_id")]
public int UserId { get; set; }
[DataMember(Name = "detail_level")]
public string DetailLevel { get; set; }
}
Please note that this solution doesn't handle EmitDefaultValue and Order properties supported by DataMember attribute.