Example
You can write detailed signals with the [Signal (detailed = true)] attribute.
public class Emitter : Object { [Signal (detailed = true)] public signal void detailed_signal (); public void emit_with_detail (string detail) { this.detailed_signal[detail] (); } } void main () { var emitter = new Emitter (); // Connect only when the detail is "foo". emitter.detailed_signal["foo"].connect (() => { print ("Received the signal with 'foo'.\n"); }); // Connect to the signal, whatever is the detail. emitter.detailed_signal.connect (() => { print ("Received the signal.\n"); }); emitter.emit_with_detail ("foo"); // Both handlers will be triggered. emitter.emit_with_detail ("bar"); // Only the general handler will be triggered. } This feature is often used with the notify signal, that any Object based class has, and which is sent when a property changes. The detail here is the name of the property, so you can choose to connect to this signal only for some of them.
public class Person : Object { public string name { get; set; } public int age { get; set; } } void main () { var john = new Person () { name = "John", age = 42 }); john.notify["age"].connect (() => { print ("Happy birthday!"); }); john.age++; } 
