#region License
// Copyright (c) 2007 James Newton-King
//
// Permission is hereby granted, free of charge, to any person
// obtaining a copy of this software and associated documentation
// files (the "Software"), to deal in the Software without
// restriction, including without limitation the rights to use,
// copy, modify, merge, publish, distribute, sublicense, and/or sell
// copies of the Software, and to permit persons to whom the
// Software is furnished to do so, subject to the following
// conditions:
//
// The above copyright notice and this permission notice shall be
// included in all copies or substantial portions of the Software.
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
// EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES
// OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
// NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT
// HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
// WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
// FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
// OTHER DEALINGS IN THE SOFTWARE.
#endregion
using System;
using System.Collections.Generic;
using System.Globalization;
using System.Reflection;
using System.Runtime.Serialization;
using Newtonsoft.Json.Utilities;
#if NET20
using Newtonsoft.Json.Utilities.LinqBridge;
#else
using System.Linq;
#endif
namespace Newtonsoft.Json.Converters
{
///
/// Converts an to and from its name string value.
///
internal class StringEnumConverter : JsonConverter
{
///
/// Gets or sets a value indicating whether the written enum text should be camel case.
/// The default value is false.
///
/// true if the written enum text will be camel case; otherwise, false.
public bool CamelCaseText { get; set; }
///
/// Gets or sets a value indicating whether integer values are allowed when deserializing.
/// The default value is true.
///
/// true if integers are allowed when deserializing; otherwise, false.
public bool AllowIntegerValues { get; set; }
///
/// Initializes a new instance of the class.
///
public StringEnumConverter()
{
AllowIntegerValues = true;
}
///
/// Initializes a new instance of the class.
///
/// true if the written enum text will be camel case; otherwise, false.
public StringEnumConverter(bool camelCaseText)
: this()
{
CamelCaseText = camelCaseText;
}
///
/// Writes the JSON representation of the object.
///
/// The to write to.
/// The value.
/// The calling serializer.
public override void WriteJson(JsonWriter writer, object value, JsonSerializer serializer)
{
if (value == null)
{
writer.WriteNull();
return;
}
Enum e = (Enum)value;
if (!EnumUtils.TryToString(e.GetType(), value, CamelCaseText, out string enumName))
{
if (!AllowIntegerValues)
{
throw JsonSerializationException.Create(null, writer.ContainerPath, "Integer value {0} is not allowed.".FormatWith(CultureInfo.InvariantCulture, e.ToString("D")), null);
}
// enum value has no name so write number
writer.WriteValue(value);
}
else
{
writer.WriteValue(enumName);
}
}
///
/// Reads the JSON representation of the object.
///
/// The to read from.
/// Type of the object.
/// The existing value of object being read.
/// The calling serializer.
/// The object value.
public override object ReadJson(JsonReader reader, Type objectType, object existingValue, JsonSerializer serializer)
{
if (reader.TokenType == JsonToken.Null)
{
if (!ReflectionUtils.IsNullableType(objectType))
{
throw JsonSerializationException.Create(reader, "Cannot convert null value to {0}.".FormatWith(CultureInfo.InvariantCulture, objectType));
}
return null;
}
bool isNullable = ReflectionUtils.IsNullableType(objectType);
Type t = isNullable ? Nullable.GetUnderlyingType(objectType) : objectType;
try
{
if (reader.TokenType == JsonToken.String)
{
string enumText = reader.Value.ToString();
if (enumText == string.Empty && isNullable)
{
return null;
}
return EnumUtils.ParseEnum(t, enumText, !AllowIntegerValues);
}
if (reader.TokenType == JsonToken.Integer)
{
if (!AllowIntegerValues)
{
throw JsonSerializationException.Create(reader, "Integer value {0} is not allowed.".FormatWith(CultureInfo.InvariantCulture, reader.Value));
}
return ConvertUtils.ConvertOrCast(reader.Value, CultureInfo.InvariantCulture, t);
}
}
catch (Exception ex)
{
throw JsonSerializationException.Create(reader, "Error converting value {0} to type '{1}'.".FormatWith(CultureInfo.InvariantCulture, MiscellaneousUtils.FormatValueForPrint(reader.Value), objectType), ex);
}
// we don't actually expect to get here.
throw JsonSerializationException.Create(reader, "Unexpected token {0} when parsing enum.".FormatWith(CultureInfo.InvariantCulture, reader.TokenType));
}
///
/// Determines whether this instance can convert the specified object type.
///
/// Type of the object.
///
/// true if this instance can convert the specified object type; otherwise, false.
///
public override bool CanConvert(Type objectType)
{
Type t = (ReflectionUtils.IsNullableType(objectType))
? Nullable.GetUnderlyingType(objectType)
: objectType;
return t.IsEnum();
}
}
}