[Bug - Blueprints] Interface functions without return values do not appear under "My Blueprint" for implementing classes

anonymous_user_828ce3681 · August 1, 2014, 10:19pm

I’m using UE 4.3 on Windows 7 and I’m having trouble figuring out where to provide definitions for inherited blueprint functions that do not include return values. Here are repo steps:

Create a blueprint interface and create a function that doesn’t contain any return values. Save/Compile.

2. Create an actor, add interface, save/compile, and notice function doesn’t seem to appear for actor.

3. Add another function with a return value in same interface created in step 1. Save/compile.

4. Notice only function with a return value is listed under “Interfaces” for actor created in step 2.

Is this intended behavior? official docs don’t seem to mention anything about it.

Thanks for any help/insight.

anonymous_user_dede2580 · August 1, 2014, 10:46pm

Interface functions without return values appear as custom events in implementing classes, for some reason (just in case you had not noticed and really need to implement something like right now

anonymous_user_828ce3681 · August 1, 2014, 11:13pm

Thanks , that clears up confusion. That’s a really strange and inconsistent behavior for blueprint interfaces.

anonymous_user_828ce3681 · August 2, 2014, 12:11am

Thanks to Xeonme’s clarification about where Unreal places interface functions without return values I was able to figure out how to provide definitions. Here’s full answer:

Interface functions without return values apparently will not be listed in the “My Blueprint” tab. Instead I had to use the Palette window to find generated event for function:

2. I dropped event node in a new graph and provided definition (can also use default event graph).

anonymous_user_33800a51 · August 6, 2014, 9:51pm

Hey schmit,

As points out, functions without parameters are placed as Events. interface is a bit confusing, but that is intended. I’m checking with developers to see if they want to include Events in My Blueprint panel. In meantime, what you posted above should work fine. Thanks for posting this answer for other users to find!

Villason · March 21, 2015, 9:37pm

My workaround is to always add a “success” output parameter. I don’t see why you consider a function without a return an “event”.

YogevNa · April 11, 2017, 9:19pm

Helpful workaround even after 2 years…Thanks mate, hopefully it will be changed.