VCB Notification Structure

A VCB notifiable call must have in its extensions the notifyurl key. This key, together with a few other optional extensions, controls the location and format for sending VCB notifications.

The additional keys are:

• notifybody
• notifyenc.

The logic for sending a VCB notification is as follows:

For an ORS Instance

• If notifyurl starts with ors:// then the entire notifyurl should be in the format, ors://orsname/scxml/session/orssession/event/eventname[?params], and URS will try to send an event to the specified ORS and the specified session within it.
• If notifyurl starts with ors: then the entire notifyurl should be in the format, ors:whatever/event/eventname[?params], and URS will try to send an event to the ORS node and the session associated with this VCB call.

In both the above cases, the optional params and notifybody can be provided.

• params should have the format of an URL encoded string of parameters.
• notifybody could either be an URL encoded string of parameters or a JSON string.

Their values if provided will be decoded first – any fragment in square brackets will be replaced with its actual value as given below:

[udata]	entire call attached data (& separated)
[udata.*]	entire call attached data (, separated)
[udata.key]	value of corresponding attached data
[udataj]	entire call attached data as JSON string
[ext]	all call extensions (& separated)
[ext.*]	all call extensions (, separated)
[ext.key]	value of corresponding extension key
[extj]	all call extensions as JSON string
[orssession]	ORS session ID if call has associated ORS session ID
[ors]	host:port of ORS node associated with this VCB call
[call.connid]	Connection ID of this VCB call
[call.uuid]	UUID of this VCB call

For an URS Instance

• If notifyurl starts with urs:// then the entire notifyurl should be in the format, urs://ursname/message and URS will try to send a command to the specified URS.
• If notifyurl starts with urs: then the entire notifyurl should be in the format, urs:message and the particular URS will try to send a command to itself.

In both cases, the command is effectively invoking the RequestRouter function (updated description in the Supplement to the Universal Routing 8.1 Reference Manual):

RequestRouter[ursname, message, notifybody, ","]

Both message and notifybody preliminary will be decoded as described above.

For a Generic HTTP Server

In all other cases, URS will try to send a VCB notification as a REST HTTP message.

• notifyurl must be a valid URL.
• notifybody – If specified, URS will use POST message instead of GET message, and use notifybody as the content of this POST message.
• notifyenc – Used only if notifybody is present and will be used as the content of Content-Type header of the generated HTTP message.

Both notifyurl and notifybody preliminary will be decoded as described above.