happy-barnacle aka ObjectEventStore

Happy-Barnacle provide a REST interface to store/retrieve object events.

Object Event

An object event is an event which belong to one specific object. Nothing fancy, each event just carries an id of the object and the object's type in addition to the usual fields for a usual event sourcing. The class ObjectEvent has fields

• topic : GUID (non-null)
• time : Date (when event is stored in event store). Set by event store.
• id : number (strictly increases within topic). This uniquely identifies the event. Set by event store.
• type : string (to identify category of event, e.g. "CreateObject", non-null)
• object : GUID (non-null)
• objectType : String (non-null)
• payload: Map<String,String>

ObjectEventStore

Class Server starts a REST interface. You can either start it in your environment or use index.ts to start it directly from the shell. The server allows Cross-Origin-Requests for calls originating from localhost.

GET /objectEvent

Retrieve all objectEvents of a topic. Topic is a mandatory parameter. object and objectType are optional parameters.

POST /objectEvent

Store a new objectEvent. No need to transfer an id or time for the event, as those will be set by the server.

GET /newObjectEvents

Newly stored object events are provided via this server side event stream as well.

Encoding of payload for REST calls

Payload has to be encoded

JSON.stringify(Array.from(objectEvent.payload.entries()))

which can be converted back via

new Map<string, string>(JSON.parse(restObjectEvent.payload))