More general cleanup in MCP

Plugins/BlueprintMCP/Source/BlueprintMCP/Private/MCPHandlerPopulate.cpp

@@ -1,227 +0,0 @@
-#include "MCPHandler.h"
-#include "MCPUtils.h"
-#include "Dom/JsonObject.h"
-#include "UObject/UnrealType.h"
-#include "UObject/EnumProperty.h"
-
-namespace MCPPopulate
-{
-
-// Try to set a single FProperty on a handler from a JSON field.
-// Returns an empty string on success, or an error message on failure.
-FString SetPropertyFromJson(
-	void* Container,
-	FProperty* Prop,
-	const FString& FieldName,
-	const FJsonObject* Json)
-{
-	void* ValuePtr = Prop->ContainerPtrToValuePtr<void>(Container);
-
-	// FString
-	if (FStrProperty* StrProp = CastField<FStrProperty>(Prop))
-	{
-		if (!Json->HasTypedField<EJson::String>(FieldName))
-		{
-			return FString::Printf(TEXT("'%s' must be a string"), *FieldName);
-		}
-		StrProp->SetPropertyValue(ValuePtr, Json->GetStringField(FieldName));
-		return FString();
-	}
-
-	// int32
-	if (FIntProperty* IntProp = CastField<FIntProperty>(Prop))
-	{
-		if (!Json->HasTypedField<EJson::Number>(FieldName))
-		{
-			return FString::Printf(TEXT("'%s' must be a number"), *FieldName);
-		}
-		IntProp->SetPropertyValue(ValuePtr, (int32)Json->GetNumberField(FieldName));
-		return FString();
-	}
-
-	// float
-	if (FFloatProperty* FloatProp = CastField<FFloatProperty>(Prop))
-	{
-		if (!Json->HasTypedField<EJson::Number>(FieldName))
-		{
-			return FString::Printf(TEXT("'%s' must be a number"), *FieldName);
-		}
-		FloatProp->SetPropertyValue(ValuePtr, (float)Json->GetNumberField(FieldName));
-		return FString();
-	}
-
-	// double
-	if (FDoubleProperty* DoubleProp = CastField<FDoubleProperty>(Prop))
-	{
-		if (!Json->HasTypedField<EJson::Number>(FieldName))
-		{
-			return FString::Printf(TEXT("'%s' must be a number"), *FieldName);
-		}
-		DoubleProp->SetPropertyValue(ValuePtr, Json->GetNumberField(FieldName));
-		return FString();
-	}
-
-	// bool
-	if (FBoolProperty* BoolProp = CastField<FBoolProperty>(Prop))
-	{
-		if (!Json->HasTypedField<EJson::Boolean>(FieldName))
-		{
-			return FString::Printf(TEXT("'%s' must be a boolean"), *FieldName);
-		}
-		BoolProp->SetPropertyValue(ValuePtr, Json->GetBoolField(FieldName));
-		return FString();
-	}
-
-	// Enum (FEnumProperty — C++ enum class)
-	if (FEnumProperty* EnumProp = CastField<FEnumProperty>(Prop))
-	{
-		if (!Json->HasTypedField<EJson::String>(FieldName))
-		{
-			return FString::Printf(TEXT("'%s' must be a string"), *FieldName);
-		}
-		FString ValueStr = Json->GetStringField(FieldName);
-		UEnum* Enum = EnumProp->GetEnum();
-		int64 EnumVal = Enum->GetValueByNameString(ValueStr);
-		if (EnumVal == INDEX_NONE)
-		{
-			return FString::Printf(TEXT("'%s': unknown enum value '%s'"), *FieldName, *ValueStr);
-		}
-		FNumericProperty* UnderlyingProp = EnumProp->GetUnderlyingProperty();
-		UnderlyingProp->SetIntPropertyValue(ValuePtr, EnumVal);
-		return FString();
-	}
-
-	// Enum (FByteProperty with Enum — old-style UENUM)
-	if (FByteProperty* ByteProp = CastField<FByteProperty>(Prop))
-	{
-		if (ByteProp->Enum)
-		{
-			if (!Json->HasTypedField<EJson::String>(FieldName))
-			{
-				return FString::Printf(TEXT("'%s' must be a string"), *FieldName);
-			}
-			FString ValueStr = Json->GetStringField(FieldName);
-			int64 EnumVal = ByteProp->Enum->GetValueByNameString(ValueStr);
-			if (EnumVal == INDEX_NONE)
-			{
-				return FString::Printf(TEXT("'%s': unknown enum value '%s'"), *FieldName, *ValueStr);
-			}
-			ByteProp->SetPropertyValue(ValuePtr, (uint8)EnumVal);
-			return FString();
-		}
-		// Plain byte without enum — treat as number
-		if (!Json->HasTypedField<EJson::Number>(FieldName))
-		{
-			return FString::Printf(TEXT("'%s' must be a number"), *FieldName);
-		}
-		ByteProp->SetPropertyValue(ValuePtr, (uint8)Json->GetNumberField(FieldName));
-		return FString();
-	}
-
-	// FMCPJsonObject — stash a JSON object into the struct
-	if (FStructProperty* StructProp = CastField<FStructProperty>(Prop))
-	{
-		if (StructProp->Struct == FMCPJsonObject::StaticStruct())
-		{
-			if (!Json->HasTypedField<EJson::Object>(FieldName))
-			{
-				return FString::Printf(TEXT("'%s' must be an object"), *FieldName);
-			}
-			FMCPJsonObject* Obj = StructProp->ContainerPtrToValuePtr<FMCPJsonObject>(Container);
-			Obj->Json = Json->GetObjectField(FieldName);
-			return FString();
-		}
-
-		// FMCPJsonArray — stash a JSON array into the struct
-		if (StructProp->Struct == FMCPJsonArray::StaticStruct())
-		{
-			if (!Json->HasTypedField<EJson::Array>(FieldName))
-			{
-				return FString::Printf(TEXT("'%s' must be an array"), *FieldName);
-			}
-			FMCPJsonArray* Arr = StructProp->ContainerPtrToValuePtr<FMCPJsonArray>(Container);
-			Arr->Array = Json->GetArrayField(FieldName);
-			return FString();
-		}
-	}
-
-	return FString::Printf(TEXT("'%s': unsupported property type '%s'"),
-		*FieldName, *Prop->GetCPPType());
-}
-
-// Convert a property name from PascalCase to camelCase, matching JSON conventions.
-// e.g. "BlueprintName" -> "blueprintName", "PosX" -> "posX"
-FString PropertyNameToJsonKey(const FString& PropName)
-{
-	if (PropName.IsEmpty())
-	{
-		return PropName;
-	}
-	FString Result = PropName;
-	Result[0] = FChar::ToLower(Result[0]);
-	return Result;
-}
-
-} // namespace MCPPopulate
-
-FString MCPUtils::PopulateFromJson(
-	UStruct* StructType,
-	void* Container,
-	const TSharedPtr<FJsonValue>& JsonValue)
-{
-	if (!JsonValue.IsValid() || (JsonValue->Type != EJson::Object))
-	{
-		return TEXT("Expected a JSON object");
-	}
-	return PopulateFromJson(StructType, Container, JsonValue->AsObject().Get());
-}
-
-FString MCPUtils::PopulateFromJson(
-	UStruct* StructType,
-	void* Container,
-	const FJsonObject* Json)
-{
-	// Build a set of known property names (as JSON keys) for the unknown-field check.
-	TSet<FString> KnownKeys;
-	TArray<FProperty*> Properties;
-
-	for (TFieldIterator<FProperty> It(StructType, EFieldIterationFlags::None); It; ++It)
-	{
-		FProperty* Prop = *It;
-		Properties.Add(Prop);
-		KnownKeys.Add(MCPPopulate::PropertyNameToJsonKey(Prop->GetName()));
-	}
-
-	// Check for unknown fields in the JSON
-	for (const auto& KV : Json->Values)
-	{
-		if (!KnownKeys.Contains(KV.Key))
-		{
-			return FString::Printf(TEXT("Unknown parameter '%s'"), *KV.Key);
-		}
-	}
-
-	// Populate each property from JSON
-	for (FProperty* Prop : Properties)
-	{
-		FString JsonKey = MCPPopulate::PropertyNameToJsonKey(Prop->GetName());
-		bool bOptional = Prop->HasMetaData(TEXT("Optional"));
-
-		if (!Json->HasField(JsonKey))
-		{
-			if (!bOptional)
-			{
-				return FString::Printf(TEXT("Missing required parameter '%s'"), *JsonKey);
-			}
-			continue;
-		}
-
-		FString Error = MCPPopulate::SetPropertyFromJson(Container, Prop, JsonKey, Json);
-		if (!Error.IsEmpty())
-		{
-			return Error;
-		}
-	}
-
-	return FString();
-}

Plugins/BlueprintMCP/Source/BlueprintMCP/Private/MCPUtils.cpp

@@ -1,4 +1,5 @@
 #include "MCPUtils.h"
+#include "MCPHandler.h"
 #include "BlueprintActionDatabase.h"
 #include "BlueprintNodeSpawner.h"
 #include "Dom/JsonValue.h"
@@ -1220,3 +1221,220 @@ TArray<UBlueprintNodeSpawner*> MCPUtils::SearchNodeSpawners(const FString& Query
 	}
 	return Result;
 }
+
+// ============================================================
+// PopulateFromJson — fill a USTRUCT from a JSON object
+// ============================================================
+
+#include "UObject/UnrealType.h"
+#include "UObject/EnumProperty.h"
+
+FString MCPUtils::PropertyNameToJsonKey(const FString& PropName)
+{
+	if (PropName.IsEmpty())
+	{
+		return PropName;
+	}
+	FString Result = PropName;
+	Result[0] = FChar::ToLower(Result[0]);
+	return Result;
+}
+
+FString MCPUtils::SetPropertyFromJson(
+	void* Container, FProperty* Prop, const FString& FieldName, const FJsonObject* Json)
+{
+	void* ValuePtr = Prop->ContainerPtrToValuePtr<void>(Container);
+
+	// FString
+	if (FStrProperty* StrProp = CastField<FStrProperty>(Prop))
+	{
+		if (!Json->HasTypedField<EJson::String>(FieldName))
+		{
+			return FString::Printf(TEXT("'%s' must be a string"), *FieldName);
+		}
+		StrProp->SetPropertyValue(ValuePtr, Json->GetStringField(FieldName));
+		return FString();
+	}
+
+	// int32
+	if (FIntProperty* IntProp = CastField<FIntProperty>(Prop))
+	{
+		if (!Json->HasTypedField<EJson::Number>(FieldName))
+		{
+			return FString::Printf(TEXT("'%s' must be a number"), *FieldName);
+		}
+		IntProp->SetPropertyValue(ValuePtr, (int32)Json->GetNumberField(FieldName));
+		return FString();
+	}
+
+	// float
+	if (FFloatProperty* FloatProp = CastField<FFloatProperty>(Prop))
+	{
+		if (!Json->HasTypedField<EJson::Number>(FieldName))
+		{
+			return FString::Printf(TEXT("'%s' must be a number"), *FieldName);
+		}
+		FloatProp->SetPropertyValue(ValuePtr, (float)Json->GetNumberField(FieldName));
+		return FString();
+	}
+
+	// double
+	if (FDoubleProperty* DoubleProp = CastField<FDoubleProperty>(Prop))
+	{
+		if (!Json->HasTypedField<EJson::Number>(FieldName))
+		{
+			return FString::Printf(TEXT("'%s' must be a number"), *FieldName);
+		}
+		DoubleProp->SetPropertyValue(ValuePtr, Json->GetNumberField(FieldName));
+		return FString();
+	}
+
+	// bool
+	if (FBoolProperty* BoolProp = CastField<FBoolProperty>(Prop))
+	{
+		if (!Json->HasTypedField<EJson::Boolean>(FieldName))
+		{
+			return FString::Printf(TEXT("'%s' must be a boolean"), *FieldName);
+		}
+		BoolProp->SetPropertyValue(ValuePtr, Json->GetBoolField(FieldName));
+		return FString();
+	}
+
+	// Enum (FEnumProperty — C++ enum class)
+	if (FEnumProperty* EnumProp = CastField<FEnumProperty>(Prop))
+	{
+		if (!Json->HasTypedField<EJson::String>(FieldName))
+		{
+			return FString::Printf(TEXT("'%s' must be a string"), *FieldName);
+		}
+		FString ValueStr = Json->GetStringField(FieldName);
+		UEnum* Enum = EnumProp->GetEnum();
+		int64 EnumVal = Enum->GetValueByNameString(ValueStr);
+		if (EnumVal == INDEX_NONE)
+		{
+			return FString::Printf(TEXT("'%s': unknown enum value '%s'"), *FieldName, *ValueStr);
+		}
+		FNumericProperty* UnderlyingProp = EnumProp->GetUnderlyingProperty();
+		UnderlyingProp->SetIntPropertyValue(ValuePtr, EnumVal);
+		return FString();
+	}
+
+	// Enum (FByteProperty with Enum — old-style UENUM)
+	if (FByteProperty* ByteProp = CastField<FByteProperty>(Prop))
+	{
+		if (ByteProp->Enum)
+		{
+			if (!Json->HasTypedField<EJson::String>(FieldName))
+			{
+				return FString::Printf(TEXT("'%s' must be a string"), *FieldName);
+			}
+			FString ValueStr = Json->GetStringField(FieldName);
+			int64 EnumVal = ByteProp->Enum->GetValueByNameString(ValueStr);
+			if (EnumVal == INDEX_NONE)
+			{
+				return FString::Printf(TEXT("'%s': unknown enum value '%s'"), *FieldName, *ValueStr);
+			}
+			ByteProp->SetPropertyValue(ValuePtr, (uint8)EnumVal);
+			return FString();
+		}
+		// Plain byte without enum — treat as number
+		if (!Json->HasTypedField<EJson::Number>(FieldName))
+		{
+			return FString::Printf(TEXT("'%s' must be a number"), *FieldName);
+		}
+		ByteProp->SetPropertyValue(ValuePtr, (uint8)Json->GetNumberField(FieldName));
+		return FString();
+	}
+
+	// FMCPJsonObject — stash a JSON object into the struct
+	if (FStructProperty* StructProp = CastField<FStructProperty>(Prop))
+	{
+		if (StructProp->Struct == FMCPJsonObject::StaticStruct())
+		{
+			if (!Json->HasTypedField<EJson::Object>(FieldName))
+			{
+				return FString::Printf(TEXT("'%s' must be an object"), *FieldName);
+			}
+			FMCPJsonObject* Obj = StructProp->ContainerPtrToValuePtr<FMCPJsonObject>(Container);
+			Obj->Json = Json->GetObjectField(FieldName);
+			return FString();
+		}
+
+		// FMCPJsonArray — stash a JSON array into the struct
+		if (StructProp->Struct == FMCPJsonArray::StaticStruct())
+		{
+			if (!Json->HasTypedField<EJson::Array>(FieldName))
+			{
+				return FString::Printf(TEXT("'%s' must be an array"), *FieldName);
+			}
+			FMCPJsonArray* Arr = StructProp->ContainerPtrToValuePtr<FMCPJsonArray>(Container);
+			Arr->Array = Json->GetArrayField(FieldName);
+			return FString();
+		}
+	}
+
+	return FString::Printf(TEXT("'%s': unsupported property type '%s'"),
+		*FieldName, *Prop->GetCPPType());
+}
+
+FString MCPUtils::PopulateFromJson(
+	UStruct* StructType,
+	void* Container,
+	const TSharedPtr<FJsonValue>& JsonValue)
+{
+	if (!JsonValue.IsValid() || (JsonValue->Type != EJson::Object))
+	{
+		return TEXT("Expected a JSON object");
+	}
+	return PopulateFromJson(StructType, Container, JsonValue->AsObject().Get());
+}
+
+FString MCPUtils::PopulateFromJson(
+	UStruct* StructType,
+	void* Container,
+	const FJsonObject* Json)
+{
+	// Build a set of known property names (as JSON keys) for the unknown-field check.
+	TSet<FString> KnownKeys;
+	TArray<FProperty*> Properties;
+
+	for (TFieldIterator<FProperty> It(StructType, EFieldIterationFlags::None); It; ++It)
+	{
+		FProperty* Prop = *It;
+		Properties.Add(Prop);
+		KnownKeys.Add(PropertyNameToJsonKey(Prop->GetName()));
+	}
+
+	// Check for unknown fields in the JSON
+	for (const auto& KV : Json->Values)
+	{
+		if (!KnownKeys.Contains(KV.Key))
+		{
+			return FString::Printf(TEXT("Unknown parameter '%s'"), *KV.Key);
+		}
+	}
+
+	// Populate each property from JSON
+	for (FProperty* Prop : Properties)
+	{
+		FString JsonKey = PropertyNameToJsonKey(Prop->GetName());
+		bool bOptional = Prop->HasMetaData(TEXT("Optional"));
+
+		if (!Json->HasField(JsonKey))
+		{
+			if (!bOptional)
+			{
+				return FString::Printf(TEXT("Missing required parameter '%s'"), *JsonKey);
+			}
+			continue;
+		}
+
+		FString Error = SetPropertyFromJson(Container, Prop, JsonKey, Json);
+		if (!Error.IsEmpty())
+		{
+			return Error;
+		}
+	}
+
+	return FString();
+}

Plugins/BlueprintMCP/Source/BlueprintMCP/Public/MCPUtils.h

@@ -94,4 +94,8 @@ public:
 	// ----- Property population -----
 	static FString PopulateFromJson(UStruct* StructType, void* Container, const TSharedPtr<FJsonValue>& JsonValue);
 	static FString PopulateFromJson(UStruct* StructType, void* Container, const FJsonObject* Json);
+
+private:
+	static FString PropertyNameToJsonKey(const FString& PropName);
+	static FString SetPropertyFromJson(void* Container, FProperty* Prop, const FString& FieldName, const FJsonObject* Json);
 };