Better param checks for Studio Mode request types

PROTOCOL.md

@@ -377,7 +377,7 @@ Studio Mode only. Sets the specified scene as the Previewed scene in Studio Mode
 __Request fields__ :  
 - **"scene-name"** (string) : name of the scene to selected as the preview of Studio Mode
 
-__Response__ : OK if specified scene exists, error otherwise.
+__Response__ : OK if Studio Mode is enabled and specified scene exists, error otherwise.
 
 ---
 
@@ -387,10 +387,10 @@ Studio Mode only. Transitions the currently previewed scene to Program (main out
 __Request fields__ :  
 - **"with-transition" (object, optional) : if specified, use this transition when switching from preview to program. This will change the current transition in the frontend to this one.
 
-__Response__ : always OK. No additional fields
+__Response__ : OK if studio mode is enabled and optional transition exists, error otherwise.
 
 An object passed as `"with-transition"` in a request must have the following fields :  
-- **"name"** (string) : transition name
+- **"name"** (string, optional) : transition name
 - **"duration"** (integer, optional) : transition duration in milliseconds
 
 ---

WSRequestHandler.cpp

@@ -788,13 +788,19 @@ void WSRequestHandler::HandleGetPreviewScene(WSRequestHandler *owner)
 
 void WSRequestHandler::HandleSetPreviewScene(WSRequestHandler *owner)
 {
-	const char* scene_name = obs_data_get_string(owner->_requestData, "scene-name");
+	if (!Utils::IsPreviewModeActive())
-	if (!scene_name)
+	{
+		owner->SendErrorResponse("studio mode not enabled");
+		return;
+	}
+
+	if (!obs_data_has_user_value(owner->_requestData, "scene-name"))
 	{
 		owner->SendErrorResponse("invalid request parameters");
 		return;
 	}
 
+	const char* scene_name = obs_data_get_string(owner->_requestData, "scene-name");
 	Utils::SetPreviewScene(scene_name);
 
 	owner->SendOKResponse();
@@ -802,28 +808,36 @@ void WSRequestHandler::HandleSetPreviewScene(WSRequestHandler *owner)
 
 void WSRequestHandler::HandleTransitionToProgram(WSRequestHandler *owner)
 {
-	obs_data_t* transitionInfo = obs_data_get_obj(owner->_requestData, "with-transition");
+	if (!Utils::IsPreviewModeActive())
-
-	if (transitionInfo)
 	{
-		const char* transitionName = obs_data_get_string(transitionInfo, "name");
+		owner->SendErrorResponse("studio mode not enabled");
-		int transitionDuration = obs_data_get_int(transitionInfo, "duration");
+		return;
+	}
 
-		if (!transitionName)
+	if (obs_data_has_user_value(owner->_requestData, "with-transition"))
+	{
+		obs_data_t* transitionInfo = obs_data_get_obj(owner->_requestData, "with-transition");
+
+		if (obs_data_has_user_value(transitionInfo, "name"))
 		{
-			owner->SendErrorResponse("specified transition doesn't exist");
+			const char* transitionName = obs_data_get_string(transitionInfo, "name");
-			return;
+			bool success = Utils::SetTransitionByName(transitionName);
+
+			if (!success)
+			{
+				owner->SendErrorResponse("specified transition doesn't exist");
+				obs_data_release(transitionInfo);
+				return;
+			}
 		}
 
-		bool success = Utils::SetTransitionByName(transitionName);
+		if (obs_data_has_user_value(transitionInfo, "duration"))
-		if (!success)
 		{
-			owner->SendErrorResponse("unknown error while trying to change current transition");
+			int transitionDuration = obs_data_get_int(transitionInfo, "duration");
-			return;
-		}
-
-		if (transitionDuration > 0)
 			Utils::SetTransitionDuration(transitionDuration);
+		}
+		
+		obs_data_release(transitionInfo);
 	}
 
 	Utils::TransitionToProgram();