discourse-wiki-related

A minimal Discourse plugin that renders precomputed, site-scoped outbound reference cards on public topic pages. It never queries the destination, computes similarity, or matches content at render time — a validated TopicCustomField, populated by an external job, supplies the ordered links. The plugin's only job is to present that data safely.

Two card kinds ship, each with its own custom field, its own settings, and its own origin allowlist:

Kind	Custom field	Allow-listed origins
wiki	wiki_related	wiki.objectivismonline.com, wiki.freecapitalists.org
archive	archive_related	freecapitalists.org

The repository name predates the second kind. Both are defined as data in lib/discourse_wiki_related/kind.rb and share one presenter, so a third destination is a table entry rather than another copy of the validation code.

In the browser, each enabled card appears as a compact reference strip below the topic title and category, before the first post. The crawler view carries the same ordered links after the posts through Discourse's server-rendered HTML hook.

Why

Communities that run a companion MediaWiki alongside their Discourse forum want topic pages to surface relevant wiki articles. Doing that lookup live, on every page view, is unnecessary work and an unnecessary trust boundary. This plugin keeps rendering dumb and fast: a precomputation step (cron job, admin script, whatever) writes the related links to a topic custom field, and this plugin only ever displays what's already there — after validating it.

What it guards against

The presenter (lib/discourse_wiki_related/presenter.rb) fails closed and suppresses the card entirely rather than rendering anything malformed:

• rows written for a different community (site_key mismatch)
• rows built for the other card. Both kinds store the same row shape, so a row states its own kind; a row that states none is a wiki row, which is what every row written before the archive card existed is
• rows written for a community that origin is not paired with, which is what stops a Liberty Archive card from ever rendering on Objectivism Online
• links pointing outside that kind's allow-listed origin (host + scheme + no userinfo/port/query)
• malformed or missing stored JSON
• private, unlisted, deleted, read-restricted, or non-public topics
• personal messages (only the default archetype is eligible)

The browser serializer and the crawler-facing HTML builder (server:topic-show-after-posts-crawler) both call the same presenter, so logged-in users, anonymous visitors, and search-engine crawlers see identical, identically-validated links.

Installation

Add the plugin to your Discourse container the standard way — either clone it into containers/<container>.yml under plugins: (see the Discourse install-plugin guide) as:

- git clone https://github.com/DavidVeksler/discourse-wiki-related.git

or, for a development checkout, clone directly into plugins/:

cd plugins
git clone https://github.com/DavidVeksler/discourse-wiki-related.git

Then rebuild/restart Discourse.

Configuration

The plugin is inert after installation. Configure these site settings per Discourse site (Admin → Settings → Plugins):

Setting	Purpose	Default
wiki_related_enabled	Wiki card on/off	false
wiki_related_wiki_base_url	Allow-listed wiki origin (https:// scheme, no path/query)	""
wiki_related_heading	Wiki card heading text	Related on the wiki
wiki_related_max_links	Max wiki links shown (1–3)	3
archive_related_enabled	Archive card on/off	false
archive_related_base_url	Allow-listed archive origin	""
archive_related_heading	Archive card heading text	Free on the Liberty Archive
archive_related_max_links	Max archive links shown (1–3)	3

The two toggles are independent: there is deliberately no plugin-level enabled_site_setting, because one would have let the wiki card's switch silently gate the archive card. Enable a kind last, after its base URL is set and its origin is paired with a site in lib/discourse_wiki_related/kind.rb.

Test

From a Discourse checkout with this repository installed at plugins/discourse-wiki-related:

bin/lint plugins/discourse-wiki-related
bin/rspec plugins/discourse-wiki-related/spec

Development

See AGENTS.md for the doc-routing table used by coding agents working in this repo.

MIT licensed.