From e6ce1cebb31b460883e78756ad5356dbe8d2aa53 Mon Sep 17 00:00:00 2001
From: Sipke Schoorstra <sipkeschoorstra@outlook.com>
Date: Wed, 8 Mar 2023 00:31:51 +0100
Subject: [PATCH] Stash

---
 .../WorkflowDefinitions/Post/Endpoint.cs      |  2 +-
 .../Activities/Composite.cs                   |  2 +-
 .../Attributes/JsonExpandableAttribute.cs     |  9 +++
 .../Converters/JsonExpandableConverter.cs     | 57 +++++++++++++++++++
 .../SerializerOptionsProvider.cs              |  7 ++-
 .../WorkflowDefinitionActivity.cs             |  5 +-
 6 files changed, 78 insertions(+), 4 deletions(-)
 create mode 100644 src/modules/Elsa.Workflows.Core/Attributes/JsonExpandableAttribute.cs
 create mode 100644 src/modules/Elsa.Workflows.Core/Serialization/Converters/JsonExpandableConverter.cs

diff --git a/src/modules/Elsa.Workflows.Api/Endpoints/WorkflowDefinitions/Post/Endpoint.cs b/src/modules/Elsa.Workflows.Api/Endpoints/WorkflowDefinitions/Post/Endpoint.cs
index a80350c12..de8f194e4 100644
--- a/src/modules/Elsa.Workflows.Api/Endpoints/WorkflowDefinitions/Post/Endpoint.cs
+++ b/src/modules/Elsa.Workflows.Api/Endpoints/WorkflowDefinitions/Post/Endpoint.cs
@@ -64,7 +64,7 @@ internal class Post : ElsaEndpoint<WorkflowDefinitionRequest, WorkflowDefinition
 
         // Update the draft with the received model.
         var root = request.Root ?? new Sequence();
-        var serializerOptions = _serializerOptionsProvider.CreateApiOptions();
+        var serializerOptions = _serializerOptionsProvider.CreatePersistenceOptions();
         var stringData = JsonSerializer.Serialize(root, serializerOptions);
         var variables = _variableDefinitionMapper.Map(request.Variables).ToList();
         var inputs = request.Inputs ?? new List<InputDefinition>();
diff --git a/src/modules/Elsa.Workflows.Core/Activities/Composite.cs b/src/modules/Elsa.Workflows.Core/Activities/Composite.cs
index c5953a6a7..05925dd3e 100644
--- a/src/modules/Elsa.Workflows.Core/Activities/Composite.cs
+++ b/src/modules/Elsa.Workflows.Core/Activities/Composite.cs
@@ -43,7 +43,7 @@ public abstract class Composite : Activity, IVariableContainer
     /// </summary>
     [Port]
     [Browsable(false)]
-    [JsonIgnore] // Composite activities' Root is intended to be constructed from code only.
+    //[JsonExpandable] // Composite activities' Root is intended to be constructed from code only.
     public IActivity Root { get; set; } = new Sequence();
 
     /// <inheritdoc />
diff --git a/src/modules/Elsa.Workflows.Core/Attributes/JsonExpandableAttribute.cs b/src/modules/Elsa.Workflows.Core/Attributes/JsonExpandableAttribute.cs
new file mode 100644
index 000000000..82f4ac540
--- /dev/null
+++ b/src/modules/Elsa.Workflows.Core/Attributes/JsonExpandableAttribute.cs
@@ -0,0 +1,9 @@
+namespace Elsa.Workflows.Core.Attributes;
+
+/// <summary>
+/// Used by a custom converter to indicate that the property should be expanded into a JSON object.
+/// </summary>
+[AttributeUsage(AttributeTargets.Property)]
+public class JsonExpandableAttribute : Attribute
+{
+}
\ No newline at end of file
diff --git a/src/modules/Elsa.Workflows.Core/Serialization/Converters/JsonExpandableConverter.cs b/src/modules/Elsa.Workflows.Core/Serialization/Converters/JsonExpandableConverter.cs
new file mode 100644
index 000000000..80d6390bd
--- /dev/null
+++ b/src/modules/Elsa.Workflows.Core/Serialization/Converters/JsonExpandableConverter.cs
@@ -0,0 +1,57 @@
+using System.Reflection;
+using System.Text.Json;
+using System.Text.Json.Serialization;
+using Elsa.Extensions;
+using Elsa.Workflows.Core.Attributes;
+
+namespace Elsa.Workflows.Core.Serialization.Converters;
+
+/// <summary>
+/// Ignores properties with the <see cref="JsonExpandableAttribute"/> attribute.
+/// </summary>
+public class JsonExpandableConverter<T> : JsonConverter<T>
+{
+    /// <inheritdoc />
+    public override T Read(ref Utf8JsonReader reader, Type typeToConvert, JsonSerializerOptions options)
+    {
+        throw new NotImplementedException();
+    }
+
+    /// <inheritdoc />
+    public override void Write(Utf8JsonWriter writer, T value, JsonSerializerOptions options)
+    {
+        writer.WriteStartObject();
+
+        var properties = typeof(T).GetProperties(BindingFlags.Public | BindingFlags.Instance);
+        var newOptions = new JsonSerializerOptions(options);
+        
+        newOptions.Converters.RemoveWhere(x => x is JsonExpandableConverterFactory<T>);
+
+        foreach (var property in properties)
+        {
+            if (property.GetCustomAttribute<JsonExpandableAttribute>() != null)
+                continue;
+
+            var propName = options.PropertyNamingPolicy?.ConvertName(property.Name) ?? property.Name;
+            writer.WritePropertyName(propName);
+            JsonSerializer.Serialize(writer, property.GetValue(value), newOptions);
+        }
+
+        writer.WriteEndObject();
+    }
+}
+
+/// <summary>
+/// A <see cref="JsonConverterFactory"/> that creates <see cref="JsonExpandableConverter{T}"/> instances.
+/// </summary>
+public class JsonExpandableConverterFactory<T> : JsonConverterFactory
+{
+    /// <inheritdoc />
+    public override bool CanConvert(Type typeToConvert) => typeof(T).IsAssignableFrom(typeToConvert);
+
+    /// <inheritdoc />
+    public override JsonConverter CreateConverter(Type typeToConvert, JsonSerializerOptions options)
+    {
+        return new JsonExpandableConverter<T>();
+    }
+}
\ No newline at end of file
diff --git a/src/modules/Elsa.Workflows.Core/Serialization/SerializerOptionsProvider.cs b/src/modules/Elsa.Workflows.Core/Serialization/SerializerOptionsProvider.cs
index ffc225c5c..b09e37ad1 100644
--- a/src/modules/Elsa.Workflows.Core/Serialization/SerializerOptionsProvider.cs
+++ b/src/modules/Elsa.Workflows.Core/Serialization/SerializerOptionsProvider.cs
@@ -21,7 +21,12 @@ public class SerializerOptionsProvider
 
     public JsonSerializerOptions CreateApiOptions(ReferenceHandler? referenceHandler = default) => CreateDefaultOptions(referenceHandler ?? ReferenceHandler.IgnoreCycles);
 
-    public JsonSerializerOptions CreatePersistenceOptions(ReferenceHandler? referenceHandler = default) => CreateDefaultOptions(referenceHandler ?? ReferenceHandler.IgnoreCycles);
+    public JsonSerializerOptions CreatePersistenceOptions(ReferenceHandler? referenceHandler = default)
+    {
+        var options = CreateDefaultOptions(referenceHandler ?? ReferenceHandler.IgnoreCycles);
+        options.Converters.Add(Create<JsonExpandableConverterFactory<IActivity>>());
+        return options;
+    }
 
     public JsonSerializerOptions CreateDefaultOptions(ReferenceHandler? referenceHandling = default)
     {
diff --git a/src/modules/Elsa.Workflows.Management/Activities/WorkflowDefinitionActivity/WorkflowDefinitionActivity.cs b/src/modules/Elsa.Workflows.Management/Activities/WorkflowDefinitionActivity/WorkflowDefinitionActivity.cs
index f8c97bc53..6292907b3 100644
--- a/src/modules/Elsa.Workflows.Management/Activities/WorkflowDefinitionActivity/WorkflowDefinitionActivity.cs
+++ b/src/modules/Elsa.Workflows.Management/Activities/WorkflowDefinitionActivity/WorkflowDefinitionActivity.cs
@@ -17,7 +17,10 @@ namespace Elsa.Workflows.Management.Activities.WorkflowDefinitionActivity;
 [Browsable(false)]
 public class WorkflowDefinitionActivity : Activity, IInitializable
 {
-    internal IActivity Root { get; set; } = default!;
+    /// <summary>
+    /// The activity to schedule for execution.
+    /// </summary>
+    public IActivity Root { get; set; } = default!;
 
     /// <summary>
     /// The definition ID of the workflow to schedule for execution.