zotonic_mod_driebit_activity

A Zotonic module to track user activity on resources, specifically with support for the ActivityPub protocol.

This module is based upon and heavily relies on zotonic_mod_driebit_rdf, please check out its documentation as well.

Table of contents

1. Features
2. Notifications

Features

Represent resources with ActivityPub/ActivityStreams

This modules adds the ontologies, serializations, namespaces and content types necessary to represent resources within the ActivityStreams and/or ActivityPub specification.

These can be requested with content type negotiations, respectively:

curl -L -H Accept:application/activity+json https://yoursite.com/id/<id>
curl -L -H "Accept:application/ld+json; profile=\"https://www.w3.org/ns/activitystreams\"" https://yoursite.com/id/<id>

or with one of the generic RDF endpoints (see zotonic_mod_driebit_rdf), as well as with some specific ones added for convenience:

curl -L http://yoursite.com/rdf/activitystreams/<id>
curl -L http://yoursite.com/rdf/activitypub/<id>

ActivityPub support

Aside from representing standard resources and connections with them, this module also supports ActivityPub's special collections which are automatically calculated and added to Actor objects.

These can also be accessed with their individual entrypoints:

curl -L -H Accept:application/activity+json https://yoursite.com/activitypub/<id>/<collection>

where:

• <collection> can be either of inbox, outbox, following, followers and liked
• <id> is the user ID and can be omitted to see the current user's

At the moment this module only supports pulling data, and pushing, either by POST or DELETE http requests, is left for future implementation.

Admin page and authentication

This module also adds an admin page, which can be found as "ActivityPub" under the "Modules" menu, where users with access to the admin can:

1. explore the special collections of users
2. request an OAuth2 token to authenticate their requests (instead of using cookies)

Activity tracking and automations

The module doesn't track any user activity automatically by default, individual sites must decide what to track and as a consequence of what.

Most commonly one will probably have to listen to resource or edge notifications and then insert an activity resource as a consequence.

Separate categories for all of the ActivityPub's supported activity types are installed with this module, but for simplicity, m_activity has a register function to add one. For example one might want to start tracking the creation of resources with:

    m_activity:register(
        create,
        [{object, NewRscId}],
        z_acl:logon(UserId, Context)
    ).

which will add a new resource of the activity_create category, assign the UserId as its actor and the NewRscId as its object (see erlang code for details and available options).

The module on its own doesn't automate much, as the tracking and handling logic is mostly context-dependent on the site, with some exceptions:

1. ActivityPub's special collections are automatically updated when new activities are registered/published
2. Inserting an undo activity will unpublish its object activity, which excludes it from the "object" collections above

ACL and permissions

By default every user can insert new resources of the activity category (and subcategories), but only see their own.

These permissions can of course be overridden as usual.

Note: it might not be feasible or possible to use zotonic's cookies for authentication, see the admin menu to obtain an OAuth2 token instead.

Notifications

This module doesn't add any Zotonic Notification, but instead merely uses the ones from zotonic_mod_driebit_rdf and zotonic_core.

There is however an MQTT notification which is sent to each user whenever there is something new in their inbox, this uses the topic: user/<user_id>/activities.

This can also be used in templates to have push notifications with a live tag, for example:

{% if m.acl.user as user %}
    {% live
        template="notifications.tpl"
        topic=["bridge", "origin", "user", user, "activities"]
    %}
{% endif %}