Import YamlDotNet.

Assets/YamlDotNet/Serialization/Converters/DateTimeConverter.cs

@@ -0,0 +1,115 @@
+// This file is part of YamlDotNet - A .NET library for YAML.
+// Copyright (c) Antoine Aubry and contributors
+//
+// 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.
+
+using System;
+using System.Globalization;
+using System.Linq;
+
+using YamlDotNet.Core;
+using YamlDotNet.Core.Events;
+
+namespace YamlDotNet.Serialization.Converters
+{
+    /// <summary>
+    /// This represents the YAML converter entity for <see cref="DateTime"/>.
+    /// </summary>
+    public class DateTimeConverter : IYamlTypeConverter
+    {
+        private readonly DateTimeKind kind;
+        private readonly IFormatProvider provider;
+        private readonly string[] formats;
+
+        /// <summary>
+        /// Initializes a new instance of the <see cref="DateTimeConverter"/> class.
+        /// </summary>
+        /// <param name="kind"><see cref="DateTimeKind"/> value. Default value is <see cref="DateTimeKind.Utc"/>. <see cref="DateTimeKind.Unspecified"/> is considered as <see cref="DateTimeKind.Utc"/>.</param>
+        /// <param name="provider"><see cref="IFormatProvider"/> instance. Default value is <see cref="CultureInfo.InvariantCulture"/>.</param>
+        /// <param name="formats">List of date/time formats for parsing. Default value is "<c>G</c>".</param>
+        /// <remarks>On deserializing, all formats in the list are used for conversion, while on serializing, the first format in the list is used.</remarks>
+        public DateTimeConverter(DateTimeKind kind = DateTimeKind.Utc, IFormatProvider? provider = null, params string[] formats)
+        {
+            this.kind = kind == DateTimeKind.Unspecified ? DateTimeKind.Utc : kind;
+            this.provider = provider ?? CultureInfo.InvariantCulture;
+            this.formats = formats.DefaultIfEmpty("G").ToArray();
+        }
+
+        /// <summary>
+        /// Gets a value indicating whether the current converter supports converting the specified type.
+        /// </summary>
+        /// <param name="type"><see cref="Type"/> to check.</param>
+        /// <returns>Returns <c>True</c>, if the current converter supports; otherwise returns <c>False</c>.</returns>
+        public bool Accepts(Type type)
+        {
+            return type == typeof(DateTime);
+        }
+
+        /// <summary>
+        /// Reads an object's state from a YAML parser.
+        /// </summary>
+        /// <param name="parser"><see cref="IParser"/> instance.</param>
+        /// <param name="type"><see cref="Type"/> to convert.</param>
+        /// <returns>Returns the <see cref="DateTime"/> instance converted.</returns>
+        /// <remarks>On deserializing, all formats in the list are used for conversion.</remarks>
+        public object ReadYaml(IParser parser, Type type)
+        {
+            var value = parser.Consume<Scalar>().Value;
+            var style = this.kind == DateTimeKind.Local ? DateTimeStyles.AssumeLocal : DateTimeStyles.AssumeUniversal;
+
+            var dt = DateTime.ParseExact(value, this.formats, this.provider, style);
+            dt = EnsureDateTimeKind(dt, this.kind);
+            return dt;
+        }
+
+        /// <summary>
+        /// Writes the specified object's state to a YAML emitter.
+        /// </summary>
+        /// <param name="emitter"><see cref="IEmitter"/> instance.</param>
+        /// <param name="value">Value to write.</param>
+        /// <param name="type"><see cref="Type"/> to convert.</param>
+        /// <remarks>On serializing, the first format in the list is used.</remarks>
+        public void WriteYaml(IEmitter emitter, object? value, Type type)
+        {
+            var dt = (DateTime)value!;
+            var adjusted = this.kind == DateTimeKind.Local ? dt.ToLocalTime() : dt.ToUniversalTime();
+            var formatted = adjusted.ToString(this.formats.First(), this.provider); // Always take the first format of the list.
+
+            emitter.Emit(new Scalar(AnchorName.Empty, TagName.Empty, formatted, ScalarStyle.Any, true, false));
+        }
+
+        private static DateTime EnsureDateTimeKind(DateTime dt, DateTimeKind kind)
+        {
+            DateTime ensured;
+            if (dt.Kind == DateTimeKind.Local && kind == DateTimeKind.Utc)
+            {
+                ensured = dt.ToUniversalTime();
+                return ensured;
+            }
+
+            if (dt.Kind == DateTimeKind.Utc && kind == DateTimeKind.Local)
+            {
+                ensured = dt.ToLocalTime();
+                return ensured;
+            }
+
+            return dt;
+        }
+    }
+}