Overview

As a very early part of Remark.as, it would be interesting to allow replying to other fediverse posts from Write.as Web / WriteFreely.

Background

We want to encourage more thought-out responses to posts on the web. Usually if someone is going to write something well-thought-out, they'll put it on their own blog and simply link to the original post. We can facilitate this by letting writers explicitly connect their response post to an original one, and communicating this information via ActivityPub.

Implementation

Accept a new reply_to property when creating a post. This should be a URL. Upon publishing, if federation is enabled, this value should be used as the inReplyTo property on the activity we send out.

I'm not sure if we'll also need to include the original post's author / intance in the to or cc field -- this may involve some extra work retrieving this information.

Design

Ideally, we would enable this interaction via plain text in the editor.

Realistically, we could add a "reply" button at the top of the editor (when federation is enabled) that pops up an in-place modal window. It should quickly explain what the feature does and have a single field to accept a URL. Entering a URL should asynchronously retrieve the activity data for that URL while the user continues writing.

• If no valid activity data is returned, we should let the user know that they can't directly reply to that URL via ActivityPub (in the least technical way).
• If commentsEnabled is explicitly false, we should let the user know that the post's author isn't accepting replies, and we shouldn't accept the URL, include it in the inReplyTo field, etc.

In these error cases, we might still save the information locally for some other informative use.

Nice-to-have

It would be nice to be able to populate the reply field with a URL parameter on the editor page, e.g. write.as/new?replyTo={URL}