#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 Newtonsoft.Json.Utilities; using System.Globalization; namespace Newtonsoft.Json { /// <summary> /// Converts an object to and from JSON. /// </summary> internal abstract class 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 abstract void WriteJson(JsonWriter writer, object value, JsonSerializer serializer); /// <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 abstract object ReadJson(JsonReader reader, Type objectType, object existingValue, JsonSerializer serializer); /// <summary> /// Determines whether this instance can convert the specified object type. /// </summary> /// <param name="objectType">Type of the object.</param> /// <returns> /// <c>true</c> if this instance can convert the specified object type; otherwise, <c>false</c>. /// </returns> public abstract bool CanConvert(Type objectType); /// <summary> /// Gets a value indicating whether this <see cref="JsonConverter"/> can read JSON. /// </summary> /// <value><c>true</c> if this <see cref="JsonConverter"/> can read JSON; otherwise, <c>false</c>.</value> public virtual bool CanRead => true; /// <summary> /// Gets a value indicating whether this <see cref="JsonConverter"/> can write JSON. /// </summary> /// <value><c>true</c> if this <see cref="JsonConverter"/> can write JSON; otherwise, <c>false</c>.</value> public virtual bool CanWrite => true; } /// <summary> /// Converts an object to and from JSON. /// </summary> /// <typeparam name="T">The object type to convert.</typeparam> internal abstract class JsonConverter<T> : 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 sealed override void WriteJson(JsonWriter writer, object value, JsonSerializer serializer) { if (!(value != null ? value is T : ReflectionUtils.IsNullable(typeof(T)))) { throw new JsonSerializationException("Converter cannot write specified value to JSON. {0} is required.".FormatWith(CultureInfo.InvariantCulture, typeof(T))); } WriteJson(writer, (T)value, serializer); } /// <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 abstract void WriteJson(JsonWriter writer, T value, JsonSerializer serializer); /// <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 sealed override object ReadJson(JsonReader reader, Type objectType, object existingValue, JsonSerializer serializer) { bool existingIsNull = existingValue == null; if (!(existingIsNull || existingValue is T)) { throw new JsonSerializationException("Converter cannot read JSON with the specified existing value. {0} is required.".FormatWith(CultureInfo.InvariantCulture, typeof(T))); } return ReadJson(reader, objectType, existingIsNull ? default(T) : (T)existingValue, !existingIsNull, serializer); } /// <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. If there is no existing value then <c>null</c> will be used.</param> /// <param name="hasExistingValue">The existing value has a value.</param> /// <param name="serializer">The calling serializer.</param> /// <returns>The object value.</returns> public abstract T ReadJson(JsonReader reader, Type objectType, T existingValue, bool hasExistingValue, JsonSerializer serializer); /// <summary> /// Determines whether this instance can convert the specified object type. /// </summary> /// <param name="objectType">Type of the object.</param> /// <returns> /// <c>true</c> if this instance can convert the specified object type; otherwise, <c>false</c>. /// </returns> public sealed override bool CanConvert(Type objectType) { return typeof(T).IsAssignableFrom(objectType); } } }