Creating an event to be fired from C++

Development Programming & Scripting Blueprint
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1

Hello All,

I have been looking all over the web for the answer to this one but I’m getting confused and I don’t think some of the examples I found specifically show me what I need, so here is what I need help with.

I have C++ class that handles my TCPNetworking, When I get a response from the network I want to Fire and event from C++ so that my blueprint will act.

Example:

  1. Blueprint calls function in C++ to send login information to the server (working)
  2. Blueprint now waits for the response (working)
  3. When the C++ receives the message back from the server I would like to fire an event in Blueprint from C++ to continue with the login process.

Cheers

2

After posting I found a possible solution, Typical really.
Here is the link to the solution I got working.

https://answers.unrealengine.com/questions/31728/invoking-event-in-blueprint.html

Is this the recommended way? I appreciate this is only local to the class and will not allow the event to fire in all blueprints.

If anyone has further input that would be appreciated.

Thanks GrendelsMom,

3

Use the BlueprintImplentableEvent !
Create a member function in your class using:

UFUNCTION(BlueprintImplentableEvent, category = "YourCategory")
void MyEvent(/* Params*/);

Then, in your BP graph, search for your event’s name, to place it in the graph.
And when you call this function in your C++ code, it will call the Event in BP !

4

The BlueprintImplentableEvent way is more recommended, for what you are doing (see my answer for more informations).

5

Thanks for the comments,
I couldn’t get the event into a seperate blueprint so I used the following method.

DECLARE_DYNAMIC_MULTICAST_DELEGATE_OneParam(FLoginResponseDelegate, bool, authenticated);

and its delegate

UPROPERTY(BlueprintAssignable, Category = "NDG Events")
		FLoginResponseDelegate OnLogonResponseDelegate;

Then called this with

OnLogonResponseDelegate.Broadcast(authenticated == 1 ? true : false);

This now allows me to just broadcast the message so any blueprint binding to this event will be fired which is perfect.

Note:
The authenticated in the Broadcast is 1 as this is returned via my server as a single bit received in the TCP packet.

Thanks for the assist and I appreciate the extra advice on using BlueprintImplentableEvent this will be required in later classes.

6

Hello, what do you think is the drawback if we use delegate (BlueprintAssignable) instead of function (BlueprintImplentableEvent)?