obus

Pure Ocaml implementation of the D-Bus protocol
Library obus
Module OBus_object

This module allows you to create D-Bus objects and export them on a connection, allowing other programs to acccess them.

Types
type 'a t

Type of local D-Bus objects. It contains informations needed by obus to export it on a connection and dispatch incoming method calls.

'a is the type of value that may be attached to this object.

type 'a interface

An interface description

type 'a method_info

Informations about a method

type 'a signal_info

Informations about a signal

type 'a property_info

Informations about a property

Objects creation
val attach : 'a t -> 'a -> unit

attach obus_object custom_obejct attaches custom_object to obus_object. custom_object will be the value received by method call handlers. Note that you need to attach the object before you can export it on a coneection and you can not attach an object multiple times.

val get : 'a t -> 'a

get obj returns the data attached to the given object

val make : ?owner:OBus_peer.t -> ?common:bool -> ?interfaces:'a interface list -> OBus_path.t -> 'a t

make ?owner ?common ?interfaces path creates a new D-Bus object with path path.

If owner is specified, then:

  • all signals will be sent to it by default,
  • the object will be removed from all its exports when the owner exits,
  • it will automatically be exported on the connection of the owner when attach is invoked.

interfaces is the list of interfaces implemented by the object. New interfaces can be added latter with add_interfaces. If common is true (the default) then introspectable and properties are automatically added.

Properties
val path : 'a t -> OBus_path.t

path obj returns the path of the object

val owner : 'a t -> OBus_peer.t option

owner obj returns the owner of the object, if any

exports obj is a signal holding the list of connnections on which the object is exported.

val introspect : 'a t -> OBus_introspect.interface list

introspect obj returns the introspection of all interfaces implemented by obj

val on_properties_changed : 'a t -> ( OBus_name.interface -> (OBus_name.member * OBus_value.V.single option) list -> unit Lwt.t ) Pervasives.ref

Function called when one or more properties of the given object change. The new contents of the property is given along with the property name according to the org.freedesktop.DBus.Property.EmitsChangedSignal.

The default function uses the standard org.freedesktop.DBus.Properties.PropertiesChanged signal.

Exports
val export : OBus_connection.t -> 'a t -> unit

export connection obj exports obj on connection. It raises OBus_connection.Connection_closed if the connection is closed.

val remove : OBus_connection.t -> 'a t -> unit

remove connection obj removes obj from connection. It does nothing if the connection is closed.

val remove_by_path : OBus_connection.t -> OBus_path.t -> unit

remove_by_path connection path removes the object with path path on connection. It works for normal objects and dynamic nodes. It does nothing if the connection is closed.

val destroy : 'a t -> unit

destroy obj removes obj from all connection it is exported on

val dynamic : connection:OBus_connection.t -> prefix:OBus_path.t -> handler:( OBus_context.t -> OBus_path.t -> 'a t Lwt.t ) -> unit

dynamic ~connection ~prefix ~handler defines a dynamic node in the tree of object. This means that objects with a path prefixed by prefix, will be created on the fly by handler when a process try to access them.

handler receive the context and rest of path after the prefix. It may raises Not_found to indicates that there is no object under the given path.

Note: if you manually export an object with a path prefixed by prefix, it will have precedence over the one created by handler.

Interfaces
val make_interface : name:OBus_name.interface -> ?annotations:OBus_introspect.annotation list -> ?methods:'a method_info list -> ?signals:'a signal_info list -> ?properties:'a property_info list -> unit -> 'a interface

make_interface ~name ?annotations ?methods ?signals ?properties () creates a new interface

val add_interfaces : 'a t -> 'a interface list -> unit

add_interfaces obj ifaces adds suport for the interfaces described by ifaces to the given object. If an interface with the same name is already attached to the object, then it is replaced by the new one.

val remove_interfaces : 'a t -> 'a interface list -> unit

remove_interaces obj ifaces removes informations about the given interfaces from obj. If obj does not implement some of the interfaces, it does nothing.

val remove_interfaces_by_names : 'a t -> OBus_name.interface list -> unit

Same as remove_interfaces but takes only the interface names as argument.

Well-known interfaces
val introspectable : unit -> 'a interface

The org.freedesktop.DBus.Introspectable interface

val properties : unit -> 'a interface

The org.freedesktop.DBus.Properties interface

Members
val method_info : ( 'a, 'b ) OBus_member.Method.t -> ( 'c t -> 'a -> 'b Lwt.t ) -> 'c method_info

method_info desc handler creates a method-call member. handler receive the destination object of the method call and the arguments of the method call. The context of the call is also available to handler by using OBus_context.get.

val signal_info : 'a OBus_member.Signal.t -> 'b signal_info

Defines a signal. It is only used for introspection

val property_r_info : ( 'a, [ `readable ] ) OBus_member.Property.t -> ( 'b t -> 'a React.signal ) -> 'b property_info

property_r_info desc get defines a read-only property. get is called once when data is attached to an object with attach. It must return a signal holding the current value of the property.

val property_w_info : ( 'a, [ `writable ] ) OBus_member.Property.t -> ( 'b t -> 'a -> unit Lwt.t ) -> 'b property_info

property_w_info desc set defines a write-only property. set is used to set the propertry contents.

val property_rw_info : ( 'a, [ `readable | `writable ] ) OBus_member.Property.t -> ( 'b t -> 'a React.signal ) -> ( 'b t -> 'a -> unit Lwt.t ) -> 'b property_info

property_rw_info desc get set defines a readable and writable property. get and set have the same semantic as for property_r_info and property_w_info.

Signals
val emit : 'a t -> interface:OBus_name.interface -> member:OBus_name.member -> ?peer:OBus_peer.t -> 'b OBus_value.C.sequence -> 'b -> unit Lwt.t

emit obj ~interface ~member ?peer typ args emits a signal. it uses the same rules as OBus_signal.emit for choosing the destinations of the signal.