I have a function that returns a String but needs to validate the input before returning it. I've seen that in Godot there is no try/catch/exceptions but error codes are expected to be returned and parsed instead. However, if my function returns String, how can I return an error code if the inputs are invalid?
#How to raise error on function that returns String?
winter lodge
urban snow
The pattern I've been personally following for situations like this is similar to Linux's errno. Basically, the object has a field called _last_error with only public get access. On error, this is populated in the function that errored and it returns default of the type (like empty String).
I suppose another option could be to wrap String with a new RefCounted type and use it as an out parameter of the function. Then return Error instead.
🙂
winter lodge
thanks for the super quick response! i just have one question, your mention about RefCounted got me curious, im reading about it in the docs because i didn't know about it, but i can't quite understand how would you use it in this situation?
like, you create a RefCounted using the string if no errors arise, and set reference count = 1; but create the RefCounted without the string (or empty string) and set reference count to 0?
urban snow
Good question 🙂
Basically, you would create a new class (class_name RefCountedString extends RefCounted) which has a field of the string (var value: String = ""). You would create one of these in the calling code, then pass it in as a parameter to the function. Because RefCounted types are pass by reference, the function can change its value: String and the calling code can call my_ref_counted_string.value after the function returns to get the value.