Custom events

Custom events are automatically validating the arguments the client send via a client event. Everything that is possible with custom events can also be created via Alt.OnPlayerEvent.

Custom events are registered via Alt.On(eventName, delegate). The delegate can have any signature and the module checks when a event occurs if the signature of the delegate fits the event arguments the client sends.

For custom events you can't use the lambda operator because it needs to know the parameter types.

Here is a very basic sample that expects just a single string from a client event named myMessage.

We register it via Alt.On. We need to help the compiler a bit by defining the method parameter types for the generic method. The types are defined from left ro right same as in the method definition itself.

Alt.On<IPlayer, string>("myMessage", MyMessageHandler);

And the method is defined as this.

public void MyMessageHandler(IPlayer player, string message)
{            
}

The method will be called like this from client

alt.emitServer("myMessage", "my test message").

The method name doesn't really matter in this case and i just named it similar to the event name.

Supported parameter types are object, bool, int, long, uint, ulong, float, double, string, IPlayer (or any types extending IPlayer), IVehicle (or any types extending IVehicle), Dictionary<string, (any type listed here), Alt.Function, any type listed here as array e.g. int[]. Also any dictionary in dictionary, array in array, ect. endless depth types are supported, because they are resolved recursively.

Dictionaries

Any js object send via alt.emitServer will be a dictionary.

Alt.On<IPlayer, Dictionary<string, string>>("myBigObject", MyBigObjectHandler);
...
public void MyBigObjectHandler(IPlayer player, Dictionary<string, string> myBigObject)
{            
  if(!myBigObject.TryGetValue("eyeColor", out var eyeColor)) return;
  Console.WriteLine($"EyeColor: {eyeColor}");
}

And this is the client code.

const myBigObject = {firstName:"John", lastName:"Doe", eyeColor:"blue"};
alt.emitServer("myBigObject", myBigObject);

When you use object as a parameter, or type in dictionary, it will accept any type and you can manually check which type it is.