node-eventstore-postgre
Why I create this eventstore?
I firstly checked Grey Young's event store, but it only provide atom REST interface for node.js, which need too many round trips (each event for each round trip) to get events from a given aggregate.
Later I tried to find node.js event store implementations, however, many are using NOSQL databases which I don't think it will support transaction very well.
Finally, I decide write a simple one using rational database.
Inspired by Grey Young's cqrs document.
Install
npm install node-eventstore-postgre
APIs
I am using coffeescript to the usages. before everything, do this
EventStore = require 'node-eventstore-postgre'eventStore = 'postgres://ronliu:123456@localhost/test'publish #Pass in postgre connection string and publish methodeventStoreinit #Initialise necessary tables and functions using create if not exists style
Get events from a given aggregate id
It will take 2 arguments:
- aggregateId
- startOverVersion, like given 3, it should return events from version 4
events = eventStorereadEvents aggregateIdstatOverVersion
Given aggregate id, output a snap shot with version
It will take 2 arguments:
- aggregateId
snapshot = eventStorereadSnapshot aggregateId # {data: aggregate, version: version} or undefined
Write events to
It will take 4 arguments:
- aggregateId
- aggregate type
- originating version: the version when we read used to check optimistic concurrency conflicts
- events array
- snapshot
eventStorewriteEvents aggregateId'customer'2eventName: 'customerAdded'data: name: 'ron'createdOn:eventName: 'customerActivated'data: comment: 'good customer'name: 'john'isActive: true
Status
- From 0.2, it support snapshot