client.LiveEvents
Every method in this namespace: its signature, its parameters, what it returns and an example.
Methods
Follow the mailbox as it changes, without polling: one event each time a message arrives or is sent and each time a conversation changes or is deleted, resumed where it left off after a dropped connection.
LiveEvents.Stream
Follow the mailbox as it changes
Stream(ctx context.Context, opts ...nextmail.RequestOption) *nextmail.LiveEventStreamOpens the live event stream, GET /live-events as server-sent events, and delivers one event at a time for as long as you read it: message.received when a message is filed for an address, message.sent when a message sent from an address is filed in its Sent folder, thread.changed when a conversation gains or loses labels (read, starred, archived, moved, snoozed or labelled), thread.deleted when one is deleted for good, and message.status_changed when the delivery of an email sent from an address moves on, with its status: delivered, delivery_delayed, bounced, complained, failed, suppressed or cancelled. Each event is a nextmail.LiveEvent with ID, Type, OccurredAt and Data, where Data is a nextmail.Object whose addresses names the addresses it concerns and whose threadId and messageId name the conversation and the message, where there is one. No content travels in an event, so read the conversation with Threads.Get or the message with Threads.GetMessage when you need it.
The stream never ends by itself. The server closes it after 30 minutes, when the credential stops being valid, or when the connection drops, and the stream opens it again and resumes where it left off through Last-Event-ID: at once after the server closes it, and with backoff after a failure. When the server can no longer replay from that point, which happens once the event is more than 10 minutes or 1,000 events back, the stream delivers an event whose Type is nextmail.LiveEventReset before the next events: anything may have changed in between, so list again what you keep in sync. Its ID is the point the stream carries on from, and its Data holds reason, expired or unknown.
Range over All(), or call Next, Event and Err in a plain loop. Leaving the loop of All() closes the stream, and so do Close and cancelling the context, all three without an error. Close may be called from another goroutine to stop a loop that is waiting for the next event.
A key or an app limited to particular addresses gets only the events of the addresses it reaches, enforced on the server for every event.
Parameters
nextmail.WithTypes...stringOnly these kinds of event, the
constants.LiveEventTypesValues:message.received,message.sent,thread.changed,thread.deletedandmessage.status_changed. Left out, all of them. A reset is always delivered.nextmail.WithAddressstringOnly the events of this address. One the key does not reach delivers nothing rather than failing.
nextmail.WithLastEventIDstringResume after this event id, the
IDof an event an earlier stream delivered, sent as theLast-Event-IDheader. Left out, the stream starts with what happens from now on.nextmail.WithAPIKeystringOverrides the client's API key for this stream only.
Returns
The *nextmail.LiveEventStream, delivering each event as a nextmail.LiveEvent with ID, Type, OccurredAt and Data. Data holds addresses, threadId and messageId and, by type, labelIds (received), emailId (sent), addedLabelIds and removedLabelIds (changed), or emailId, status and recipients (status changed, where threadId may be null). A reset holds only reason.
Example
for event, err := range client.LiveEvents.Stream(ctx, nextmail.WithTypes(constants.LiveEventTypesMessageReceived)).All() { if err != nil { return err } if event.Type == nextmail.LiveEventReset { fmt.Println("Resync: the stream could not resume") continue } thread, err := client.Threads.Get(ctx, event.Data.String("threadId")) if err != nil { return err } fmt.Println("New mail for", event.Data.Strings("addresses"), "in", thread.ID()) return nil}Notes
One key, app or session holds at most 5 open streams, and a workspace at most 50. Past that the stream is refused with 429
too_many_streams.The server sends a keepalive every 25 seconds and a
retryhint of 3 seconds. Events are kept for resuming for 10 minutes and at most 1,000 per workspace.A network failure and a 408, 429 or 5xx answer are retried for as long as you read, waiting about a second at first and doubling up to 30 seconds, or longer when
Retry-Afterasks, up to 5 minutes.nextmail.WithMaxRetriesdoes not limit it. When no byte arrives for 60 seconds, the stream drops the connection and opens it again.A 400, 401, 403, 404 or 422 ends the stream with the
*nextmail.ErrorthatErrreturns instead of retrying, so an expired or revoked credential ends it on the next attempt to open it. An answer that is not an event stream ends it the same way, with the codeunrecognised_response.The client timeout, or
nextmail.WithTimeouton the call, bounds only the wait for the stream to open, not how long it stays open.
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