feature: Add Parse & TryParse to EmbedBuilder & Add ToJsonString extension (#2284)

* Add parse & tryparse to embedbuilder.

* Add tostring extension for embeds

* Modify comments

* Resolve suggestions

* Update src/Discord.Net.Rest/Extensions/StringExtensions.cs

Co-authored-by: Quin Lynch <49576606+quinchs@users.noreply.github.com>

src/Discord.Net.Core/Entities/Messages/EmbedBuilder.cs

@@ -3,6 +3,7 @@ using System.Collections.Generic;
 using System.Collections.Immutable;
 using System.Linq;
 using Discord.Utils;
+using Newtonsoft.Json;
 
 namespace Discord
 {
@@ -155,6 +156,55 @@ namespace Discord
             }
         }
 
+        /// <summary>
+        ///     Tries to parse a string into an <see cref="EmbedBuilder"/>. 
+        /// </summary>
+        /// <param name="json">The json string to parse.</param>
+        /// <param name="builder">The <see cref="EmbedBuilder"/> with populated values. An empty instance if method returns <see langword="false"/>.</param>
+        /// <returns><see langword="true"/> if <paramref name="json"/> was succesfully parsed. <see langword="false"/> if not.</returns>
+        public static bool TryParse(string json, out EmbedBuilder builder)
+        {
+            builder = new EmbedBuilder();
+            try
+            {
+                var model = JsonConvert.DeserializeObject<Embed>(json);
+
+                if (model is not null)
+                {
+                    builder = model.ToEmbedBuilder();
+                    return true;
+                }
+                return false;
+            }
+            catch
+            {
+                return false;
+            }
+        }
+
+        /// <summary>
+        ///     Parses a string into an <see cref="EmbedBuilder"/>.
+        /// </summary>
+        /// <param name="json">The json string to parse.</param>
+        /// <returns>An <see cref="EmbedBuilder"/> with populated values from the passed <paramref name="json"/>.</returns>
+        /// <exception cref="InvalidOperationException">Thrown if the string passed is not valid json.</exception>
+        public static EmbedBuilder Parse(string json)
+        {
+            try
+            {
+                var model = JsonConvert.DeserializeObject<Embed>(json);
+
+                if (model is not null)
+                    return model.ToEmbedBuilder();
+
+                return new EmbedBuilder();
+            }
+            catch
+            {
+                throw;
+            }
+        }
+
         /// <summary>
         ///     Sets the title of an <see cref="Embed"/>.
         /// </summary>

src/Discord.Net.Rest/Extensions/StringExtensions.cs

@@ -0,0 +1,47 @@
+using Discord.Net.Converters;
+using Newtonsoft.Json;
+using System.Linq;
+using System;
+
+namespace Discord.Rest
+{
+    /// <summary>
+    ///     Responsible for formatting certain entities as Json <see langword="string"/>, to reuse later on.
+    /// </summary>
+    public static class StringExtensions
+    {
+        private static Lazy<JsonSerializerSettings> _settings = new(() =>
+        {
+            var serializer = new JsonSerializerSettings()
+            {
+                ContractResolver = new DiscordContractResolver()
+            };
+            serializer.Converters.Add(new EmbedTypeConverter());
+            return serializer;
+        });
+
+        /// <summary>
+        ///     Gets a Json formatted <see langword="string"/> from an <see cref="EmbedBuilder"/>.
+        /// </summary>
+        /// <remarks>
+        ///     See <see cref="EmbedBuilder.TryParse(string, out EmbedBuilder)"/> to parse Json back into embed.
+        /// </remarks>
+        /// <param name="builder">The builder to format as Json <see langword="string"/>.</param>
+        /// <param name="formatting">The formatting in which the Json will be returned.</param>
+        /// <returns>A Json <see langword="string"/> containing the data from the <paramref name="builder"/>.</returns>
+        public static string ToJsonString(this EmbedBuilder builder, Formatting formatting = Formatting.Indented)
+            => ToJsonString(builder.Build(), formatting);
+
+        /// <summary>
+        ///     Gets a Json formatted <see langword="string"/> from an <see cref="Embed"/>.
+        /// </summary>
+        /// <remarks>
+        ///     See <see cref="EmbedBuilder.TryParse(string, out EmbedBuilder)"/> to parse Json back into embed.
+        /// </remarks>
+        /// <param name="embed">The embed to format as Json <see langword="string"/>.</param>
+        /// <param name="formatting">The formatting in which the Json will be returned.</param>
+        /// <returns>A Json <see langword="string"/> containing the data from the <paramref name="embed"/>.</returns>
+        public static string ToJsonString(this Embed embed, Formatting formatting = Formatting.Indented)
+            => JsonConvert.SerializeObject(embed.ToModel(), formatting, _settings.Value);
+    }
+}