Microsoft.Azure.Cosmos/src/Spatial/Converters/PositionJsonConverter.cs

//------------------------------------------------------------
// Copyright (c) Microsoft Corporation.  All rights reserved.
//------------------------------------------------------------

namespace Microsoft.Azure.Cosmos.Spatial.Converters
{
    using System;
    using Microsoft.Azure.Documents;
    using Newtonsoft.Json;

    /// <summary>
    /// Converter for <see cref="Position" /> class.
    /// </summary>
    internal sealed class PositionJsonConverter : JsonConverter
    {
        /// <summary>
        /// Writes the JSON representation of the object.
        /// </summary>
        /// <param name="writer">
        /// The <see cref="T:Newtonsoft.Json.JsonWriter" /> to write to.
        /// </param>
        /// <param name="value">The existingValue.</param>
        /// <param name="serializer">The calling serializer.</param>
        public override void WriteJson(JsonWriter writer, object value, JsonSerializer serializer)
        {
            Position position = (Position)value;
            serializer.Serialize(writer, position.Coordinates);
        }

        /// <summary>
        /// Reads the JSON representation of the object.
        /// </summary>
        /// <param name="reader">The <see cref="T:Newtonsoft.Json.JsonReader" /> to read from.</param>
        /// <param name="objectType">Type of the object.</param>
        /// <param name="existingValue">The existing existingValue of object being read.</param>
        /// <param name="serializer">The calling serializer.</param>
        /// <returns>
        /// Deserialized object.
        /// </returns>
        public override object ReadJson(
            JsonReader reader,
            Type objectType,
            object existingValue,
            JsonSerializer serializer)
        {
            double[] coordinates = serializer.Deserialize<double[]>(reader);

            if (coordinates == null || coordinates.Length < 2)
            {
                throw new JsonSerializationException(RMResources.SpatialInvalidPosition);
            }

            return new Position(coordinates);
        }

        /// <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 override bool CanConvert(Type objectType)
        {
            return objectType == typeof(Position);
        }
    }
}