Function PushFunction

Plugins/UnLua/Source/UnLua/Private/LuaCore.cpp:887–929

* Push a Lua function (by a function name) and push a UObject instance as its first parameter */

 * Push a Lua function (by a function name) and push a UObject instance as its first parameter
 */
int32 PushFunction(lua_State *L, UObjectBaseUtility *Object, const char *FunctionName)
{
    int32 N = lua_gettop(L);
    lua_pushcfunction(L, UnLua::ReportLuaCallError);
    const auto& Env = UnLua::FLuaEnv::FindEnv(L);
    const auto Ref = Env->GetObjectRegistry()->GetBoundRef((UObject*)Object);
    if (Ref != LUA_NOREF)
    {
        lua_rawgeti(L, LUA_REGISTRYINDEX, Ref);
        int32 Type = lua_type(L, -1);
        if (Type == LUA_TTABLE /*|| Type == LUA_TUSERDATA*/)
        {
            if (lua_getmetatable(L, -1) == 1)
            {
                do
                {
                    lua_pushstring(L, FunctionName);
                    lua_rawget(L, -2);
                    if (lua_isfunction(L, -1))
                    {
                        lua_pushvalue(L, -3);
                        lua_remove(L, -3);
                        lua_remove(L, -3);
                        lua_pushvalue(L, -2);
                        return luaL_ref(L, LUA_REGISTRYINDEX);
                    }
                    else
                    {
                        lua_pop(L, 1);
                        lua_pushstring(L, "Super");
                        lua_rawget(L, -2);
                        lua_remove(L, -2);
                    }
                } while (lua_istable(L, -1));
            }
        }
    }
    if (int32 NumToPop = lua_gettop(L) - N)
    {
        lua_pop(L, NumToPop);
    }
    return LUA_NOREF;
}

/**
 * Push a Lua function (by a function reference) and push a UObject instance as its first parameter