Pure Ocaml implementation of the D-Bus protocol
Library obus
Module OBus_signal
Emitting signals
val emit : 'a OBus_member.Signal.t -> 'b OBus_object.t -> ?peer:OBus_peer.t -> 'a -> unit Lwt.t

emit signal obj ?peer args emits signal from obj. The destinations of the signal are selected as follow:

  • if peer is provided, then the message is sent only to it
  • otherwise, if the the object has an owner, it is sent to the owner,
  • otherwise, the message is broadcasted on all the connections obj is exported on.
Receving signals
type 'a t

Type of a signal descriptor. A signal descriptor represent the source of a signal and describes how the value should be transformed.

val make : 'a OBus_member.Signal.t -> OBus_proxy.t -> 'a t

make signal proxy creates a signal descriptor.

val make_any : 'a OBus_member.Signal.t -> OBus_peer.t -> (OBus_proxy.t * 'a) t

make_any signal peer creates a signal descriptor for receiving signals from any object of peer.

val connect : ?switch:Lwt_switch.t -> 'a t -> 'a React.event Lwt.t

connect ?switch sd connects the signal descriptor sd and returns the event which occurs when the given D-Bus signal is received.

Signals transformations and parameters
val map_event : ( (OBus_context.t * 'a) React.event -> (OBus_context.t * 'b) React.event ) -> 'a t -> 'b t

map_event f sd transforms with f the event that is created when sd is connected.

val map : ( 'a -> 'b ) -> 'a t -> 'b t

Simplified version of map_event.

val map_with_context : ( OBus_context.t -> 'a -> 'b ) -> 'a t -> 'b t

Same as map but the mapping function also receive the context.

val with_context : 'a t -> (OBus_context.t * 'a) t
  • returns

    a signal descriptor that returns contexts in which signals are received.

val with_filters : OBus_match.arguments -> 'a t -> 'a t

with_filters filters sd is the signal descriptor sd with the given list of argument filters. When connected, obus will add this filters to the matching rule send to the message bus, so the bus can use them to drop messages that do not match these filters.

The goal of argument filters is to reduce the number of messages received, and so to reduce the number of wakeup of the program.

Note that match rule management must be activated for filters to take effect (see with_match_rule).

val with_match_rule : bool -> 'a t -> 'a t

with_match_rule state sd enables or disables the automatic management of matching rules. If the endpoint of the underlying connection is a message bus it defaults to true, otherwise it default to false.