[Hiitch]

For me I just did this :

new Spawned[MAX_PLAYERS]; (can go anywhere)

Under > OnPlayerRequestSpawn < put : Spawned[playerid] = 0;

Under > OnPlayerSpawn < put : Spawned[playerid] = 1;

Under > OnPlayerText < put :

if (Spawned[playerid] == 0)
{
SendClientMessage(playerid, 0xFF0000FF, "You need to spawn to talk !");
return 0;
}

and under OnPlayerCommandText put :

if (Spawned[playerid] == 0) return SendClientMessage(playerid, 0xFF0000FF, "You are not spawned !");
{
}

See if that works. I made this today because I was thinking about that too

For the login part, you will have to put Spawned[playerid] = 1) somewhere // 1 means Is Spawned and 0 means isnt spawned.