[JAMES-3531] JMAP RFC-8620 SSE transport should manage Last-Event-Id

• Type: Sub-task
• Status: Open
• Priority: Major
• Resolution: Unresolved
• Affects Version/s: 3.6.0
• Component/s: JMAP
• Assignee: Antoine Duprat
• Reporter: Benoit Tellier
• Created: 04/Apr/21 10:15
• Updated: 04/Apr/21 10:15

Description

According to https://jmap.io/spec-core.html#event-source

The server SHOULD also send a new event id that encodes the entire server state visible to 
the user immediately after sending a state event. When a new connection is made to the 
event-source endpoint, a client following the server-sent events specification will send a 
Last-Event-ID HTTP header field with the last id it saw, which the server can use to work 
out whether the client has missed some changes. If so, it SHOULD send these changes 
immediately on connection.

This is currently not implemented.

This enable re-synchronization in the face of intermittent network connection using only SSE, without API calls.

This is somehow equivalent to RFC-8887 (JMAP over websocket) `pushState` mechanism. See https://tools.ietf.org/html/rfc8887.