#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
#if !SILVERLIGHT
using System;
using System.Data;
namespace Newtonsoft.Json.Converters{
/// <summary>
/// Converts a <see cref="DataTable"/> to and from JSON.
/// </summary>
public class DataTableConverter : JsonConverter
{
/// <summary>
/// Writes the JSON representation of the object.
/// </summary>
/// <param name="writer">The <see cref="JsonWriter"/> to write to.</param>
/// <param name="value">The value.</param>
/// <param name="serializer">The calling serializer.</param>
public override void WriteJson(JsonWriter writer, object value, JsonSerializer serializer)
{
DataTable table = (DataTable)value;
writer.WriteStartArray();
foreach (DataRow row in table.Rows)
{
writer.WriteStartObject();
foreach (DataColumn column in row.Table.Columns)
{
writer.WritePropertyName(column.ColumnName);
serializer.Serialize(writer, row[column]);
}
writer.WriteEndObject();
}
writer.WriteEndArray();
}
/// <summary>
/// Reads the JSON representation of the object.
/// </summary>
/// <param name="reader">The <see cref="JsonReader"/> to read from.</param>
/// <param name="objectType">Type of the object.</param>
/// <param name="existingValue">The existing value of object being read.</param>
/// <param name="serializer">The calling serializer.</param>
/// <returns>The object value.</returns>
public override object ReadJson(JsonReader reader, Type objectType, object existingValue, JsonSerializer serializer)
{
DataTable dt;
if (reader.TokenType == JsonToken.PropertyName)
{
dt = new DataTable((string)reader.Value);
reader.Read();
}
else
{
dt = new DataTable();
}
reader.Read();
while (reader.TokenType == JsonToken.StartObject)
{
DataRow dr = dt.NewRow();
reader.Read();
while (reader.TokenType == JsonToken.PropertyName)
{
string columnName = (string) reader.Value;
reader.Read();
if (!dt.Columns.Contains(columnName))
{
Type columnType = GetColumnDataType(reader.TokenType);
dt.Columns.Add(new DataColumn(columnName, columnType));
}
dr[columnName] = reader.Value;
reader.Read();
}
dr.EndEdit();
dt.Rows.Add(dr);
reader.Read();
}
reader.Read();
return dt;
}
private static Type GetColumnDataType(JsonToken tokenType)
{
switch (tokenType)
{
case JsonToken.Integer:
return typeof (long);
case JsonToken.Float:
return typeof (double);
case JsonToken.String:
case JsonToken.Null:
case JsonToken.Undefined:
return typeof (string);
case JsonToken.Boolean:
return typeof (bool);
case JsonToken.Date:
return typeof (DateTime);
default:
throw new ArgumentOutOfRangeException();
}
}
/// <summary>
/// Determines whether this instance can convert the specified value type.
/// </summary>
/// <param name="valueType">Type of the value.</param>
/// <returns>
/// <c>true</c> if this instance can convert the specified value type; otherwise, <c>false</c>.
/// </returns>
public override bool CanConvert(Type valueType)
{
return (valueType == typeof(DataTable));
}
}
}
#endif
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