Resumption of multiple sessions

[tidoust]

Description

If a page created two different sessions for the same URL and presentation ID on two different screens, how can it reconnect to both sessions?

The current algorithm for reconnecting sessions returns the session that was most recently connected to.

Proposal

Should joinSession rather return an array of PresentationSession objects?
Should the page rather use different presentation IDs?

References

See initial discussion in https://lists.w3.org/Archives/Public/public-secondscreen/2015Jan/0012.html

[markafoltz]

A related issue is when the page calls startSession(url, id) when there is an existing presentation with the same url and id. The current algorithm indicates that a new presentation session is always started, but the fate of the existing session is not specified. The user agent could:

1. Keep the existing session, which would allow the scenario posted originally in this issue to occur. However, joinSession and other algorithms would need to be modified to handle the (url, id) ambiguity.
2. Close the existing session only if a different screen was chosen. Otherwise act as if joinSession was called and reconnect to the existing presentation.
3. Always close the existing session (even if the same screen was chosen)

2 seems to match the intent of the user in most cases (i.e. redirecting a presentation to a different screen), as opposed to multicasting an identical presentation to multiple screens.

[tidoust]

See related discussion at F2F:
http://www.w3.org/2015/05/20-webscreens-minutes.html#item06

PROPOSED RESOLUTION: drop id from startSession() without strong use case, the UA generates the id

[markafoltz]

Closing this issue as PR #109 implements the resolution from the F2F, and there hasn't been further comment.