Reading Events

Some reads need the events themselves rather than a state, and fit neither Load nor a projection, for example one page of a long history, the events up to a certain one, or a single event. To read the events of a subject as they are stored, call the Read function with a context, the store, the subject, and the options of the client SDK. It returns an iterator over the events and errors:

options := eventsourcingdb.ReadEventsOptions{
  LowerBound: &eventsourcingdb.Bound{ID: afterEventID, Type: eventsourcingdb.BoundTypeExclusive},
}

for event, err := range architecturekit.Read(context.TODO(), store, "/books/42", options) {
  if err != nil {
    // ...
  }

  // ...
}

Every event is verified, like everything else the store reads, before the loop sees it (see Verifying Events). A failure belongs to a category, as with Load (see Handling Errors), and ends the iteration. The store stops reading as soon as the loop ends, so breaking out of it after a page is fine.

The events come as they are stored, without upcasters or rules, since there is no state. To get at the data of an event, call the Decode function (see Executing Commands).