EventArgs class

Represents data (arguments) that is provided to subscribers when an Event occurs. It includes two values:- whenOccurred - the date/time the Event is broadcast, and eventName - an optional name that can be used to identify the associated event.

Extend this class with your own custom derived class, to provide subscribers with some specific data relating to an Event.

// example custom arguments
class MyValue extends EventArgs {
  int myValue;
  MyValue(this.myValue);
}
...
var e = Event<MyValue>();
e.subscribe((args) => print(args.myValue);
e.broadcast(MyValue(99));
// prints 99
}

Note: An EventArgs instance is broadcast even when not explicitly specified as an argument to the broadcast method. This means that eventName and whenOccurred are always available.

// example ...
var e = Event();   // (#1)
e.subscribe((args) => print(args.whenOccurred);
e.broadcast();  // (#2)

// prints the date/time the Event e is broadcast.
// (#1) equivalent to Event<EventArgs>()
// (#2) same as e.broadcast(EventArgs());

As a shortcut to creating your own custom EventArgs derived class, you can use one of the two provided derived classes:- Value and Values. These classes let you provide one or two typed values to your subscribers. See the descriptions of these two classes.

Implementers

Constructors

EventArgs.new()

Properties

eventName ↔ String?
The name of associated Event. Default value is null. Typically set by external code.
getter/setter pair
hashCode → int
The hash code for this object.
no setterinherited
runtimeType → Type
A representation of the runtime type of the object.
no setterinherited
whenOccurred ↔ DateTime?
The date/time when the event is broadcast. Until broadcast, the value is null.
getter/setter pair

Methods

noSuchMethod(Invocation invocation) → dynamic
Invoked when a nonexistent method or property is accessed.
inherited
toString() → String
A string representation of this object.
inherited

Operators

operator ==(Object other) → bool
The equality operator.
inherited