Takes a reducer and an adapter and returns a repository. A repository is the layer of our Onion Architecture (see Introduction) which handles data persistence.
The write-model repository has a single method called getById. When invoked, it uses the adapter to load all events for given ID and runs them through the reducer to calculate the current state. It returns an object that contains state and also a save method, which is used to append new events.
build({ adapter, reducer })
builds a repository
| attribute | type | description |
|---|---|---|
adapter |
object |
Any object which implements the write-model Adapter Interface. |
reducer |
function |
a function which, given a list of events, knows how to calculate the current state of an object. |
{ getById } - an object with the getById function.
getById(id)
Loads and returns the current state of an entity. Also returns a save function for appending new events to the data store.
| attribute | type | description |
|---|---|---|
id |
string |
the id of the entity |
{ state, save } - an object containing an arbitrary state object, and a save function.
save(events)
Appends new events to the datastore
| attribute | type | description |
|---|---|---|
events |
array |
an array of arbitrary event objects |
null