Get GameMode, Call Methods from JavaScript

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1

I am able to call JavaScript functions from an UE4 game. . .but I’d like to go the other way. Basically, I want to see if I can flush out a user interface using HTML/CSS. For instance, I’d like to have a button event that starts the game, pauses the game, etc.

How do I go about getting the GameMode? Call a method within the class?

I’ve tried Embind (Embind — Emscripten 3.1.39-git (dev) documentation) but without success at the moment.

Any help is appreciated.

Thank you.

2

Based on this: [HTML5] Call C++ UFUNCTION from Webpage via JavaScript - Platform & Builds - Epic Developer Community Forums
and this:124477-
I ended up performing the following:

FirstPersonGameMode.cpp



#ifdef EMSCRIPTEN
#include <emscripten.h>
#endif



#ifdef EMSCRIPTEN
extern "C" {

 AFirstPersonGameMode* EMSCRIPTEN_KEEPALIVE EmscriptenGetGameMode()
 {
  if (GEngine)
  {
   TArray<APlayerController*> Players;
   GEngine->GetAllLocalPlayerControllers(Players);

   if (Players.Num() > 0)
   {
    const UWorld* World = Players[0]->GetWorld();
    if (World)
    {
     return Cast<AFirstPersonGameMode>(World->GetAuthGameMode());
    }
   }
  }

  return NULL;
 }


 void EMSCRIPTEN_KEEPALIVE JSStartGame()
 {
  AFirstPersonGameMode* gameMode = EmscriptenGetGameMode();
  if (gameMode)
  {
   gameMode->JSStartPlay();
  }
 }
}
#endif

Then in my JavaScript function:



    <script>
        function startGame() {
            Module.ccall('JSStartGame', ], ]);
        }

        function setScore(score) {
            document.getElementById("score").value = score;
        }
    </script>
<body>
    <div>
        <button id="" type="button" onclick="startGame()">Start Game</button>
        <p>Score: <input type="text" id="score" /></p>
    </div>
</body>

When the score changes I call the JavaScript function from the UE4 FirstPersonPlayerState.cpp:



#ifdef EMSCRIPTEN
#include <emscripten.h>
#endif


void AFirstPersonPlayerState::AddScore(float score)
{
 //GEngine->AddOnScreenDebugMessage(-1, 3.0f, FColor::Red, "AddScore called");
 Score += score;

#ifdef EMSCRIPTEN
 EM_ASM_ARGS({ setScore($0); }, Score);
#endif
}