Palasthotel Content Change Observer

Content Change Observer tells one WordPress site what changed on another. The observed site records modifications – saved and deleted posts, and anything a theme or plugin reports – and the sites observing it receive them and react in their own code, for example to refresh a cached teaser list or a mirrored menu.

The plugin moves no content by itself. It transports the modification (content id, content type, create/update/delete and time); what happens next is up to the content_observer_on_modifications action on the observing site.

• Connect sites as observer, observable or both, secured by an API key
• Modifications are pushed hourly (notify) or pulled on demand (fetch)
• Admin pages to manage connections and inspect and apply modifications
• WP-CLI commands for every step, so a system cron can replace WP-Cron

Typical uses:

• A portal clears its cached teaser list as soon as an article on the news site changes
• Several sites rebuild a mirrored navigation when the main site’s menu changes
• A central search site re-indexes changed posts and drops deleted ones
• An archive site stores a copy of every article, so it survives a later deletion

Developer documentation: github.com/palasthotel/wp-palasthotel-content-change-observer

External services

The plugin only talks to the WordPress sites an administrator connects under Content Change Observer → Manage. It sends them this site’s URL, its API key and the list of modifications, and requests theirs. No other service is contacted.