plainleaf/website/Service.md

The SilverBullet service bus is an extension mechanism built into SilverBullet.

Concepts

• Discovery: the process of discovering available services based on a selector.
• Selector: a string (possibly with a wildcard *) used to advertise as well as discover services.
• Service: defined via API/service#service.define(spec)), implements a service advertised via a selector.
• Invocation: running a discovered service.

Architecture

Services are an abstraction built on top of Event. When a new service is defined, it registers itself listening to the discover:<<selector>> event (to be discovered), and under service:<<guid>> to be invoked.

Service discovery happens by broadcasting an event on the event bus with the given selector, returning a list of services that are a match, ordered by (self assigned) priority. One (or all) of these services can then be invoked based on their returned ID.

See API/service for API details.