RSVPs with Webmentions

The last big Webmention feature that I wanted to support on both, my website and webmentiond, were event RSVPs. With these participants of, for instance, a user group meetup can indicate whether or not they plan to attend in a decentralised fashion as opposed to something like Meetup.com where both the event’s website and the participants’ RSVPs are stored on a single, centralised platform.

RSVPs using Webmentions are basically extensions to comments. If I want to indicate that I’m going to be at this month’s GoGraz meetup, then I just have to publish something like this and ping the GoGraz website:

<div class="h-entry">
	<a class="u-author" href="https://zerokspot.com">Horst Gutmann</a> RSVPs with
    <span class="p-rsvp">yes</span> for 
    <a class="u-in-reply-of" href="https://gograz.org/meetup/2020-06-16/">GoGraz June 2020 meetup</a>.
</div>

The only “new” element here is the p-rsvp which can have 1 of 4 distinct values:

• yes, I’m going to attend
• no, I’m not going to attend
• maybe I’m going to be there
• interested as in I’ll keep an eye out for this event but otherwise don’t know yet if I even consider attending.

The spec allows for two variants how that RSVP property can be set:

1. Using the node’s text value directly as value for the RSVP: <span class="p-rsvp">maybe</span>
2. Or using the data element in case you want the actual visible text to be something other than one of those 4 values: <data class="p-rsvp" value="yes">I'm going to be there!</data>.

At this point I’ve implemented the sending-part of RSVPs on zerokspot.com and most of the receiving-side on webmentiond. For the next couple of days I want to focus on fine-tuning that and ideally also ship a simple widget with webmentiond that sites can integrate in order to easily render received mentions. The first user of this widget will most likely be GoGraz.org so that my RSVP finally shows up there 😅