Hide duplicates on WordCamp attendees page

[hlashbrooke]

If someone buys a WordCamp ticket and then also registers for Contributor Day using a ticket (which is how many WordCamps manage things), then by default they appear twice on the Attendees page. Example of this on the WCEU 2019 page here: ​https://2019.europe.wordcamp.org/attendees/

We should hide duplicates from appearing on that page. The simplest solution would be to hide them based on their email address, but it might be more robust to match on multiple criteria (name, surname and email address together).

[coreymckrill]

@hlashbrooke the camptix_attendees shortcode takes a comma-separated list of ticket IDs as a parameter. Could this be fixed by only including the ID for the general admission ticket, and not the separate Contributor Day ticket? It looks like that might be what was done for 2019.europe.

[casiepa]

@coreymckrill as a workaround this might have done the job, but the same issue exists with volunteer tickets: Somebody buys a standard ticket, then decides to apply as volunteer, gets accepted and is asked to take the (normally free) volunteer ticket. So that person now has 2 tickets and will (probably) be shown twice.
There will be both cases for volunteers:

• Bought a normal ticket, then took the volunteers one (so keeps both)
• Waited for the volunteers ticket and only has that one

A check might have to be done to exclude any double entries of name-email unique combination.

[dd32]

Replying to casiepa:

@coreymckrill as a workaround this might have done the job, but the same issue exists with volunteer tickets: Somebody buys a standard ticket, then decides to apply as volunteer, gets accepted and is asked to take the (normally free) volunteer ticket. So that person now has 2 tickets and will (probably) be shown twice.

It used to be that only one attendee would be shown per email address, but it looks like that was recently changed - ​https://github.com/Automattic/camptix/commit/594077b9500ae18a04b7d76d06b1d5919d4d139c

You can also just mark one of the tickets as private, so that it doesn't show in the attendee listing.

[dd32]

This ticket has been moved to GitHub ​https://github.com/WordPress/wordcamp.org/issues/623