[impossible_cc]

I'm sorry if this was mentioned somewhere.

Everything below is about players-entities only (PostThinkPost)

1. Will this be a problem if I hook the same function to the same entity twice in a row without unhooking?

2. Will this be a problem if I unhook something that was not even hooked?

3. Is there any way to check is there any active hook with certain callback?

4. Is disconnecting of a player (or entire plugin stopped working) the only condition when it unhooks everything itself?

5. What is better to do.

a) often hook/unhook
b) hook once but most time it is not needed

Thanks in advance
Sorry for bad English.

[adma]

1. Hooking an entity twice with the same callback will make the callback fire twice
2. No, according to https://sm.alliedmods.net/new-api/sdkhooks/SDKUnhook, there are no error conditions for SDKUnhook
3. Not built into SDKHooks, but it is possible. One way would be to keep a global count for each hook-callback and increment it every time a player is hooked, and then decrement the count when the player leaves (unhooked). Then you can check if count > 0 e.g.

PHP Code:

int g_iCount = 0;
public void OnClientPutInServer(int iClient) {
  SDKHook(iClient, /* blah */);
  g_iCount++;
}

public void OnClientDisconnect(iClient) {
  g_iCount--;
} 


4. Player is unhooked when they disconnect and when the plugin is unloaded
5. Depends on what you want to achieve. Most of the time, you can hook and forget. If you want a one time action, you can hook them, then SDKUnhook in the callback