Revision Difference
EventSystem#544154
<cat>Code.Misc</cat>
<title>Event System</title>
The event system is like the Hook system in Garry's Mod. It allows you to register functions on classes to receive a callback on certain global events.
## Registering a callback
Adding an `[Event]` attribute will add it to the list to be called.
```
[Event( "server.tick" )]
public void MyCallback()
{
// will get called every server tick
}
```
## Engine events
The various events called from the engine currently:
⤶
### buildinput⤶
⤶
Called clientside every frame to process input and encode outputs into a user command.⤶
⤶
```csharp⤶
[Event.BuildInput]⤶
public void MyBuildInput( InputBuilder input )⤶
{⤶
⤶
}⤶
```⤶
### client.disconnect
Called when a client disconnects.
```csharp
[Event( "client.disconnected" )]
```
Called from `GameLoop.ClientDisconnected`
### frame
Called just before the beginning of a rendering frame.
```csharp
[Event( "frame" )]⤶
[Event.Frame]⤶
```
Called from `GameLoop.PreRender`
### tick
Called every <page text="server or client tick">GameLoop#everytick</page> (60 times a second by default).
```csharp
[Event( "tick" )]⤶
[Event.Tick]⤶
[Event( "server.tick" )]
[Event( "client.tick" )]
```
Called from `GameLoop.ServerFrame_Think` and `GameLoop.ClientFrame_Think`.
### physics.step
Called after each physics step, this is usually every tick but can be more depending on <page text="Global.PhysicsSubSteps">Sandbox.Global.PhysicsSubSteps</page>.
```csharp
[Event( "physics.step" )]
```
Called from `GameLoop.PostPhysicsStep`.
### hotloaded
Called each time your C# is hotloaded after successful recompile.
```csharp
[Event( "hotloaded" )]⤶
[Event.Hotload]⤶
```
Called from `HotloadManager.DoSwap`.
## Custom Events
You can register your own custom event callbacks and call them.
```csharp
[Event( "mygame.gameover" )]
public void OnGameOver()
{
}
public void DoGameOver()
{
Event.Run( "mygame.gameover" )
}
```
### Event arguments
Events can pass any amount of arguments too.
```csharp
[Event( "mygame.gameover" )]
public void OnGameOver( Player winner )
{
}
public void DoGameOver( Player winner )
{
Event.Run( "mygame.gameover", winner )
}
```