Summary
Modified properties on child classes does not get saved. This includes scenarios such as compiling/building verse, pushing changes (only verse and full), reopening project and so on.
Please select what you are reporting on:
Unreal Editor for Fortnite
What Type of Bug are you experiencing?
Verse
Steps to Reproduce
Assume the following structure:
parent_class := class {
@editable
MyValue : int = 4
}
child_class := class(parent_class) {
MyValue<override> : int = 12
}
some_device := class(creative_device) {
@editable
Thing1 : parent_class = parent_class{}
@editable
Thing2 : child_class = child_class{}
OnBegin<override>():void = {
Print("Thing1 value is: {Thing1.MyValue}") # Works correctly with the expected value even after changing it on editor
Print("Thing2 value is: {Thing2.MyValue}") # Will ignore any overriden value in code or editor and always shows "4"
}
}
-
On “
Thing1”, it will work properly, will show “4” on editor, and after changing the value to anything else, will properly save the updated/new value as expected without any issues. -
On “
Thing2”, it will show “4” on editor (already wrong since was supposed to be “12”). And, even if we change the value to anything else (ex. to “50”), it will not be saved. The next time that verse is compiled, project opened, or even pushing changes/launching session, that will be reverted back to being “4”.
This problem is not exclusive to this example scenario: It also happens on interfaces, on fields with unitialized values, optionals and so on… All gets reverted to the original state of closest parent with the “@editable” keyword.
On some places it can even leads to crashes (ex. unitialized properties being reseted to none). Before I discovered how to isolate and replicate the issue, this caused a lot of confusion during the development of some projects and infrastructures.
Expected Result
Overriden values (both internally on code or edited in editor) should be saved properly on devices inside the editor.
Observed Result
Overriden values does not get saved, and revert back to the initial state of the “closest” parent that implements “@editable” keyword again.
Platform(s)
UEFN/Editor
Windows 11 (v26100.4770)
Additional Notes
For additional info, as mentioned earlier on this post, it gets reverted to the closest parent that has the “@editable” keyword, such as on this example:
parent_class := class {
@editable
MyValue : int = 4
}
middle_class := class(parent_class) {
@editable # note the editable keyword here
MyValue<override> : int = 37
}
child_class := class(middle_class) {
MyValue<override> : int = 16 # no editable keyword here
}
some_device := class(creative_device) {
@editable
Thing : child_class = child_class{}
OnBegin<override>():void = {
Print("Thing value is: {Thing.MyValue}") # Will always show "37"
}
}
On the example above, the value shown in the editor will always revert back to the “37” of the “middle_class”, and not the “4” of the “parent_class”, since it is the closest parent that has the “@editable” keyword on that property.
Also note that this only happens with exposed classes as editables on the editor (such as on Creative Devices, NPC Behaviors and SceneGraph Components). If we instantiate the class only inside the code without ever exposing it to the editor, it will work properly as expected:
parent_class := class {
@editable
MyValue : int = 4
}
child_class := class(parent_class) {
MyValue<override> : int = 12
}
####
MyFunction():void = {
Thing := child_class{} # not editor exposed
Print("Value is: {Thing.MyValue}") # Prints 12 as expected
}
