Failed to add custom component at runtime

anonymous_user_f138d870 · October 28, 2015, 6:18am

I’m tried to add a custom component to blueprint A by blueprint B at runtime.
If the custom component doesn’t have any variable “expose on spawn”,
everything will be fine.
Custom component will be added to blueprint A, variable will be set before beginplay.

However, if I add a variable with “expose on spawn” checked,
component will be added to wrong blueprint B,
and it won’t call beginplay or it calls beginplay without setting the variable.
Lots of strange things will happen.

Is this a bug?
Should I only call add component only in blueprint A?

anonymous_user_359f4d3c · October 28, 2015, 9:02am

Can you show a screenshot of how you’re spawning the component and add it to the other blueprint?

anonymous_user_f138d870 · October 28, 2015, 9:24am

Correct (Added to TestActor):

64471-add+component+(correct).png

Wrong (Added to TestSystem):

64472-add+comopnent+(wrong).png

Sean_L · October 28, 2015, 3:06pm

Hello Katalla,

What does your Add Test Component function look like? Could you provide a screenshot?

anonymous_user_f138d870 · October 29, 2015, 1:43am

Test Component is a custom component. I just call the add component function.
It’s a default function generated by Unreal for every class inherented to Actor Component.

Sean_L · October 30, 2015, 2:01pm

I have attempted to reproduce your issue, but I haven’t been able to do so. Could you create and attach a simple test project that shows your issue so that I could get a better look at what’s causing the problem? Thank you.

anonymous_user_f138d870 · November 2, 2015, 2:12am

Our version is 4.9.0 with PS4 platform.
Test Project:
[link text][1]

Test Method:

Use Main.umap as Game Default Map
Press Play to simulate
TestSystem will add CorrectComponent to TestActor but add WrongComponent to TestSystem itself

CorrectComponent’s Debug Filter:

WrongComponent’s Debug Filter:

Sean_L · November 2, 2015, 2:48pm

Hello,

I have been able to reproduce your issue, and have entered a bug report, UE-22839. Thank you for your report, and for providing a test project.

Have a great day,

Sean Flint

anonymous_user_2d3ed244 · January 14, 2016, 7:20pm

A fix has been committed to the 4.11 release branch. Terrible bug, thanks so much for following up on it.

The fix is quite small, so if you’re building your own version of the engine it is trivial to pull in.