CampTix: Add "Remote" ticket type

[ryelle]

Set up a "Ticket Type", which pulls from a global list of types (set up in code) and can conditionally alter the registration process. Types are set up as a safelist of slug+name, and the type is saved in ticket post meta. This also updates the allergy & accommodations questions, by adding filters to skip rendering the question and/or reword the question text. Other ticket types are possible in the future, by filtering camptix_ticket_types & similarly working with CampTix filters.

Fixes #385

👩🏼‍💻 Dev notes…

I went through 2 architecture iterations before landing here— intentionally not using the CampTix_Addon class & instead sticking to plain namespacing so that the ticket-type files can easily access the get_type* functions. This way, we can add another file to ticket-types, ex workshop.php, and just like remote.php set it up to filter camptix_ticket_types. I tried to make minimal changes to CampTix itself & the hardcoded questions. Overall this works pretty well but I'd still be interested in any feedback.

📝 I could use copy advice!

You can see these strings "in context" in the screenshots below, but I'd appreciate better phrasing or even re-worked ideas.

• Ticket type name: I went with "Default" & "Remote/Livestream"
• Describing what the ticket types are:

  The type of ticket will determine how we set up the required questions. This
  cannot be changed once someone buys a ticket.
  
  Default: Default, in-person attendee.
  Remote/Livestream: Remote attendee, ex: watching on livestream, from home.
  

• Reworded a11y question: "Do you have any accessibility needs, such as a sign language interpreter, to participate in WordCamp?" — this is still hard-coded, but there was a request that it be re-worded to be more remote-friendly, so I removed the "wheelchair access" bit.

Screenshots

Creating a new ticket type allows for picking a type

Once a ticket is purchased, this is disabled

The ticket type is added to the ticket list table

In the ticket form, we don't ask the allergy question, and the accommodations question is updated.

How to test the changes in this Pull Request:

1. Create a ticket, pick "Remote" for the type
2. It should work, and be labelled "remote" in the list table in wp-admin
3. Go through buying a remote ticket
4. The allergy question should not be in the form
5. The a11y question should not say anything about physical access
6. Selecting yes for the a11y question should still trigger the email
7. Buy a non-remote ticket
8. Allergy & a11y questions are both present
9. Selecting yes for the allergy question should still trigger the email

[iandunn]

LGTM

[coreymckrill]

👍 Tested locally.

Some comments, but no blockers.

[coreymckrill]

What if the types were registered as an associative array, with the slug as the key? Then this function might be simpler or even unnecessary.

[ryelle]

Good idea — less magic with wp_list_* 🙂

[coreymckrill]

I would recommend using filter_input() here (everywhere) to retrieve the $_POST values, instead of referencing them directly. It gives you some built-in validation and sanitizing.

[ryelle]

The sanitization callback in register_post_meta takes care of this, but just to be extra-sure I added it.

[timiwahalahti]

For me, copy looks good.

[melchoyce]

Ticket type name: I went with "Default" & "Remote/Livestream"

I'd probably go with either one, or the other. I think "Livestream" is likely more common here, so I'd recommend just using that work as the ticket label.

[CdrMarks]

@ryelle I saw you said in #community-events on Slack the Livestream ticket type was available. I tested on my local environment and see the new feature related to ccf415b. I checked the 2020 Birmingham site where I'm an organizer and I do not see this feature available.

[ryelle]

@CdrMarks It was my mistake— I left the "don't enable this on production" flag in. It's now available for all sites.