FJsonObjectConverter::UStructToJsonObjectString

anonymous_user_85f60f41 · February 17, 2016, 5:16am

Hi, we’ve encountered an issue about property’s name in JsonObjectString, the situation is:
We have a UPROPERTY which’s type is FString named GUID.
If I launch UE4 Server from Editor and then the property’s name in JsonObjectString is “gUId”, but if I launch UE4 Server from a packaged server then it will be “guid”.

Thanks for your help .
Best regard.

anonymous_user_69b87708 · February 17, 2016, 4:01pm

Just a guess, but could GUID be protected? Have you tried renaming GUID to something else, like Id?

anonymous_user_85f60f41 · February 18, 2016, 2:27am

Nope, I’ve declared serval variables named GUID, others’s output will be “gUId”, only one will be “guid”.

anonymous_user_69b87708 · February 18, 2016, 6:41am

Ah right, sorry then, I’ve got no more ideas. You’ll have to wait for someone with more xp at this which, unfortunately, is usually a very long time (if at all). Its a pity, but the community here is not very active - I suspect that it is because ue4 has not been around for as long as some others. Good luck!

anonymous_user_b9532c9a · February 22, 2016, 9:36pm

Hi 任遊陳龍進,

Where are you seeing this case error occur? Is it within a specific blueprint? Was the original name set to gUId and then altered later?

anonymous_user_85f60f41 · February 23, 2016, 1:32am

Nope, It’s a native C++ UPROPERTY in USTRUCT, And I called jsonconverter api in native C++ as well without blueprint. And the original name is “FString GUID”.

lluo · February 23, 2016, 1:49am

Inside JsonObjectConverter.cpp, the first function reads:

FString FJsonObjectConverter::StandardizeCase(const FString &StringIn)
{
	// this probably won't work for all cases, consider downcaseing the string fully
	FString FixedString = StringIn;
	FixedString[0] = FChar::ToLower(FixedString[0]); // our json classes/variable start lower case
	FixedString.ReplaceInline(TEXT("ID"), TEXT("Id"), ESearchCase::CaseSensitive); // Id is standard instead of ID, some of our fnames use ID
	return FixedString;
}

So, the logic seems to convert the first character to lowercase, and replace any ‘ID’ to 'Id", so “GUID” will be converted like this:

“GUID” ==> “gUID”
“gUID” ==> “gUId”

But as to why in the packaged game “GUID” becomes “guid”, I have no idea

anonymous_user_85f60f41 · February 23, 2016, 2:04am

I know, I’ve no idea either.

anonymous_user_b9532c9a · February 29, 2016, 9:17pm

Hi 任遊陳龍進,

I wanted to post to let you know I am still looking into this. Once I have more information I will post back here.

anonymous_user_b9532c9a · March 1, 2016, 7:30pm

Try these changes to see if it alters the results:

Comment out the function block FJsonObjectConverter::StandardizeCase
Add string directly into FJsonObjectConverter::UStructtoJsonAttributes
Basically, comment out //FString VariableName = StandardizeCase (Property->GetName());
Next change OutJsonAttributes.Add(VariableName, JsonValue); to OutJsonAttributes.Add (Property->GetName(), JsonValue);

Please let me know if this addresses the error. If not, post back and I will continue looking for potential solutions to the errors you are seeing.

anonymous_user_b9532c9a · March 7, 2016, 6:00pm

Hi 任遊陳龍進,

We have not heard from you in several days. I am marking this thread as answered for tracking purposes. If you are still experiencing this issue, please comment with the requested information.