WIP: Redesign iMIP email to better format both HTML and plain text.

[brad2014]

These iMIP emails are sent when calendar events are sent when
calendar events containing invitees are created, updated, or deleted.

Addresses issues #12391 and #13555

The event is now presented in the mail using a tabular format.
Features of new design:

• Tabular format is visually clearer than previous bullet list.
• Organizer and attendee list are now included as labeled elements.
• RSVP accept is indicated for organizer and each attendee with a ✔︎.
• Eliminating linked design icons removes most privacy-eroding
  beacons (partially addressing issue iMip email should include images as attachments rather than HTML references to URLs on server #17187). Logo still TBD.

Also:

• Corrected some wording/spelling issues in emails.
• Renamed $meetingInviteeName to $meetingOrganizerName (someone
  confused invitee and invitor).
• Minor refactoring.

Signed-off-by: Brad Rubenstein brad@wbr.tech

[brad2014]

NOTES:

• This PR has UX design changes, and I'm open to feedback on aesthetics.
• This does not yet include updated tests.
• The set of strings subject to localization (l10n) in iMIP emails has been changed, will need to be coordinated with translators.
• It is conceivable that the HTML wrangling for the event table should be abstracted in EMailTemplate.php, but I was concerned that would create a breaking interface change, so this PR works to keep the changes all in one place.
• CalDav Reminder notification emails still use the bulleted list rather than the table - I'm not sure which is better for that purpose. No other code uses EMailTemplate::addBodyListItem in the server repo (but that doesn't mean installations with custom templates or apps haven't used it).

[brad2014]

This is how the email has changed (as it looks in Thunderbird, scrolling past the logo).

Old HTML:

---

New HTML:

---

Old plain text:

---

New plain text:

[brad2014]

Here is what the cancel messages look like:

Cancel iMIP mail - HTML

Cancel iMIP mail - plain text

[brad2014]

I'll wait until the reviewer tells me that the look is in line with what you consider acceptable, then I'll do the commit that finishes the tests and any cleanup you request. Or let me know what y'all prefer.

[jospoortvliet]

@nextcloud/designers

[skjnldsv]

Hey! Thanks for your pr!

For me the plain text emails looks like a good improvement.
But the standard html are a huuge regression. We indeed need to update our designa bit, but we're going straight to a 1990 style here. This definitely doesn't fit our project designs 😕

[brad2014]

Hey! Thanks for your pr!

For me the plain text emails looks like a good improvement.
But the standard html are a huuge regression. We indeed need to update our designa bit, but we're going straight to a 1990 style here. This definitely doesn't fit our project designs 😕

Don't be sad @skjnldsv 😄 ! I'm happy to build a different design, and the differences I'd like to preserve on the HTML side are

• no remote images (for privacy, and for support of recipients that can't access server)
• the new information (organizer, attendees), with indicators of RSVP status
• something that properly accommodates longer multi-line descriptions properly.
• mobile friendly (neither the existing or my WIP really achieves that, but this would be the time to fix it)

Unfortunately, the current EmailTemplate API builds up the two HTML/Text versions in parallel, adding semantic elements to both HTML and text in each API call. So it would be tough to leave the HTML as-is (as a list) and only upgrade the plain text (to a table), without some hack (e.g. let the EmailTemplate build both, then swap in upgraded plain text via a new EmailTemplate API point). I wouldn't do that unless a code reviewer recommended it.

Would anyone like to collaborate with me on an HTML design that fits your direction and addresses the above concerns? Even a screenshot of an idea would be useful for me to implement from. (But if folks have other priorities, I fully understand).

[brad2014]

Superceded by PR #17456