Update expression serialization and deserialization

Refined the expression serialization context and its deserialization method for more extensive usage. Also, simplified the handling of value retrieval in the DefaultExpressionDescriptorProvider. This allows greater control over serialization processes and makes the code more concise.

src/modules/Elsa.Expressions/Models/ExpressionDescriptor.cs

@@ -1,3 +1,4 @@
+using System.Text.Json;
 using Elsa.Expressions.Contracts;
 
 namespace Elsa.Expressions.Models;
@@ -7,6 +8,20 @@ namespace Elsa.Expressions.Models;
 /// </summary>
 public class ExpressionDescriptor
 {
+ /// <summary>
+ /// Initializes a new instance of the <see cref="ExpressionDescriptor"/> class.
+ /// </summary>
+ public ExpressionDescriptor()
+ {
+ // Default deserialization function.
+ Deserialize = context =>
+ {
+ return context.JsonElement.ValueKind == JsonValueKind.Object
+ ? context.JsonElement.Deserialize<Expression>((JsonSerializerOptions?)context.Options)!
+ : new Expression(context.ExpressionType, null!);
+ };
+ }
+
  /// <summary>
  /// Gets or sets the syntax name.
  /// </summary>
@@ -41,9 +56,9 @@ public class ExpressionDescriptor
  /// Gets or sets the memory block reference factory.
  /// </summary>
  public Func<MemoryBlockReference> MemoryBlockReferenceFactory { get; set; } = () => new MemoryBlockReference();
- 
+
  /// <summary>
  /// Gets or sets the expression deserialization function.
  /// </summary>
- public Func<ExpressionSerializationContext, Expression> Deserialize { get; set; } = default!; 
+ public Func<ExpressionSerializationContext, Expression> Deserialize { get; set; } = default!;
 }

src/modules/Elsa.Expressions/Models/ExpressionSerializationContext.cs

@@ -2,4 +2,7 @@
 
 namespace Elsa.Expressions.Models;
 
-public record ExpressionSerializationContext(JsonElement JsonElement, JsonSerializerOptions Options, Type MemoryBlockType);
+/// <summary>
+/// Defines the context for expression serialization.
+/// </summary>
+public record ExpressionSerializationContext(string ExpressionType, JsonElement JsonElement, JsonSerializerOptions Options, Type MemoryBlockType);

src/modules/Elsa.Workflows.Core/Serialization/Converters/InputJsonConverter.cs

@@ -47,7 +47,7 @@ public override Input<T> Read(ref Utf8JsonReader reader, Type typeToConvert, Jso
  return default!;
 
  var memoryBlockType = memoryBlockReference.GetType();
- var context = new ExpressionSerializationContext(expressionElement, options, memoryBlockType);
+ var context = new ExpressionSerializationContext(expressionTypeName!, expressionElement, options, memoryBlockType);
  var expression = expressionDescriptor!.Deserialize(context);
 
  return (Input<T>)Activator.CreateInstance(typeof(Input<T>), expression, memoryBlockReference)!;

src/modules/Elsa.Workflows.Management/Providers/DefaultExpressionDescriptorProvider.cs

@@ -62,9 +62,9 @@ private ExpressionDescriptor CreateVariableDescriptor()
  memoryBlockReferenceFactory: () => new Variable(),
  deserialize: context =>
  {
- var expressionValueElement = context.JsonElement.TryGetProperty("value", out var expressionElementValueValue) ? expressionElementValueValue : default;
- var expressionValue = expressionValueElement.Deserialize(context.MemoryBlockType, context.Options);
- return new Expression("Variable", expressionValue);
+ var valueElement = context.JsonElement.TryGetProperty("value", out var v) ? v : default;
+ var value = valueElement.Deserialize(context.MemoryBlockType, context.Options);
+ return new Expression("Variable", value);
  }
  );
  }
@@ -86,16 +86,12 @@ private ExpressionDescriptor CreateVariableDescriptor()
  IsSerializable = isSerializable,
  IsBrowsable = isBrowsable,
  HandlerFactory = sp => ActivatorUtilities.GetServiceOrCreateInstance<THandler>(sp),
- MemoryBlockReferenceFactory = memoryBlockReferenceFactory ?? (() => new MemoryBlockReference()),
- Deserialize = deserialize ??
- (context =>
- {
- return context.JsonElement.ValueKind == JsonValueKind.Object
- ? context.JsonElement.Deserialize<Expression>((JsonSerializerOptions?)context.Options)!
- : new Expression(expressionType, null!);
- })
+ MemoryBlockReferenceFactory = memoryBlockReferenceFactory ?? (() => new MemoryBlockReference())
  };
 
+ if (deserialize != null) 
+ descriptor.Deserialize = deserialize;
+
  if (monacoLanguage != null)
  descriptor.Properties = new
  {