Data Storage and Caching
The plugin stores no options and creates no database tables. It uses BuddyPress activity meta for saved previews and WordPress transients for its cache.
Activity meta
Section titled “Activity meta”Preview data is saved on the activity when it is created, through the bp_activity_after_save hook.
| Meta key | Object | Holds |
|---|---|---|
_bp_activity_link_preview_data |
activity | Preview payload for a main activity post: url, title, description, image_url, and for oEmbed videos wp_embed and embed_html. |
_bp_activity_comment_link_preview_data |
activity | Preview payload for an activity comment, with the same shape. |
Scraped titles and descriptions are sanitized before they are stored. Preview data is not saved for www.reddit.com URLs.
Rendering
Section titled “Rendering”Saved previews are appended to the activity content on display by filters, so they render on the server and show with JavaScript disabled:
bp_get_activity_content_bodyfor main activity posts.bp_activity_comment_contentfor comments (registered only when comment previews are enabled).
The iframe, div, img, button, span and i tags used by preview markup are added to BuddyPress’s allowed activity tags through bp_activity_allowed_tags.
Caching
Section titled “Caching”The parser caches per URL in a transient.
| Aspect | Detail |
|---|---|
| Key pattern | bp_oembed_<md5(url)> |
| Success TTL | DAY_IN_SECONDS (24 hours) |
| Negative cache | A genuinely empty page is stored as a bpalp_failed sentinel for 15 minutes (filterable via bp_activity_link_preview_negative_cache_ttl). |
| Not cached | Transient failures (timeout, blocked request, or an oEmbed provider that returned empty once) are retried on the next request rather than cached. |
There is no scheduled cleanup. Transients expire on their own TTL, and a fixed preview reappears once its negative-cache window passes.