View Source megaco_transport behaviour (megaco v4.6)
Megaco transport behaviour.
The following functions should be exported from a megaco_transport
callback
module:
- send_message/2 [
mandatory
] - send_message/3 [
optional
] resend_message/2 [
optional
]
Summary
Callbacks
-callback resend_message(Handle, Msg) -> ok | {cancel, Reason :: term()} | Error when Handle :: term(), Msg :: iodata(), Error :: term().
Re-send a megaco message.
Note that this function will only be called if the user has set the
resend_indication config option to
true
and it is in fact a message resend. If not both of these condition's
are meet, send_message
will be called.
If the function returns {cancel, Reason}
, this means the transport module
decided not to send the message. This is not an error. No error messages will
be issued and no error counters incremented. What actions this will result in
depends on what kind of message was sent.
In the case of requests, megaco will cancel the message in much the same way as
if megaco:cancel
had been called (after a successfull send). The information
will be propagated back to the user differently depending on how the request(s)
where issued: For requests issued using megaco:call, the info
will be delivered in the return value. For requests issued using megaco:cast
the info will be delivered via a call to the callback function
handle_trans_reply.
In the case of reply, megaco will cancel the reply and information of this will be returned to the user via a call to the callback function handle_trans_ack.
-callback send_message(Handle, Msg, Resend) -> ok | {cancel, Reason :: term()} | Error when Handle :: term(), Msg :: iodata(), Resend :: boolean(), Error :: term().
Send a megaco message.
If the function returns {cancel, Reason}
, this means the transport module
decided not to send the message. This is not an error. No error messages will
be issued and no error counters incremented. What actions this will result in
depends on what kind of message was sent.
In the case of requests, megaco will cancel the message in much the same way as
if megaco:cancel
had been called (after a successfull send). The information
will be propagated back to the user differently depending on how the request(s)
where issued: For requests issued using megaco:call, the info
will be delivered in the return value. For requests issued using megaco:cast
the info will be delivered via a call to the callback function
handle_trans_reply.
In the case of reply, megaco will cancel the reply and information of this will be returned to the user via a call to the callback function handle_trans_ack.
The function send_message/3
will only be called if the
resend_indication config option has been set
to the value flag
. The third argument, Resend
then indicates if the message
send is a resend or not.