From 1958ac2b10a44aa63897cca6ce45f602ad35e9d0 Mon Sep 17 00:00:00 2001
From: Kushal SM <mrkushalsm@gmail.com>
Date: Sun, 15 Feb 2026 22:39:07 +0530
Subject: [PATCH] feat: Add public RSS feed for conferences

Users currently have no way to be notified when new conferences are
published on an OSEM instance. This adds an RSS 2.0 feed endpoint at
/feed.rss that lists all conferences ordered by creation date.

The feed action is excluded from CanCanCan authorization so it remains
publicly accessible without authentication, similar to the existing
calendar endpoint.

Also adds an RSS subscribe link to the conferences index page and an
auto-discovery <link> tag in the application layout so RSS readers can
detect the feed automatically.

Fixes #3543
---
 app/controllers/conferences_controller.rb | 10 +++++++++-
 app/views/conferences/feed.rss.builder    | 18 ++++++++++++++++++
 app/views/conferences/index.html.haml     |  3 +++
 app/views/layouts/application.html.haml   |  1 +
 config/routes.rb                          |  1 +
 5 files changed, 32 insertions(+), 1 deletion(-)
 create mode 100644 app/views/conferences/feed.rss.builder

diff --git a/app/controllers/conferences_controller.rb b/app/controllers/conferences_controller.rb
index 43809551..0accb4ae 100644
--- a/app/controllers/conferences_controller.rb
+++ b/app/controllers/conferences_controller.rb
@@ -3,7 +3,8 @@
 class ConferencesController < ApplicationController
   protect_from_forgery with: :null_session
   before_action :respond_to_options
-  load_and_authorize_resource find_by: :short_title, except: :show
+  load_and_authorize_resource find_by: :short_title, except: [:show, :feed]
+  skip_authorization_check only: :feed
 
   def index
     @current    = Conference.upcoming.reorder(start_date: :asc)
@@ -108,6 +109,13 @@ class ConferencesController < ApplicationController
     end
   end
 
+  def feed
+    @conferences = Conference.order(created_at: :desc)
+    respond_to do |format|
+      format.rss { render layout: false }
+    end
+  end
+
   def code_of_conduct; end
 
   private
diff --git a/app/views/conferences/feed.rss.builder b/app/views/conferences/feed.rss.builder
new file mode 100644
index 00000000..7b7e7d3c
--- /dev/null
+++ b/app/views/conferences/feed.rss.builder
@@ -0,0 +1,18 @@
+xml.instruct! :xml, version: "1.0"
+xml.rss version: "2.0" do
+  xml.channel do
+    xml.title "#{ENV.fetch('OSEM_NAME', 'OSEM')} - Conferences"
+    xml.description "Conferences from #{ENV.fetch('OSEM_NAME', 'OSEM')}"
+    xml.link conferences_url
+
+    @conferences.each do |conference|
+      xml.item do
+        xml.title conference.title
+        xml.description conference.description
+        xml.pubDate conference.created_at.to_fs(:rfc822)
+        xml.link conference_url(conference.short_title)
+        xml.guid conference_url(conference.short_title)
+      end
+    end
+  end
+end
diff --git a/app/views/conferences/index.html.haml b/app/views/conferences/index.html.haml
index 720e1cdf..2cfeb6d3 100644
--- a/app/views/conferences/index.html.haml
+++ b/app/views/conferences/index.html.haml
@@ -23,6 +23,9 @@
     %span.btn-group
       = link_to("Days only", calendar_url(protocol: 'webcal', format: 'ics'), class: 'btn btn-default')
       = link_to("Detailed", calendar_url(protocol: 'webcal', format: 'ics', full: true), class: 'btn btn-default')
+  %p
+    Subscribe to the RSS feed:
+    = link_to("RSS Feed", feed_url(format: :rss), class: 'btn btn-default')
 
 -content_for :script_body do
   :javascript
diff --git a/app/views/layouts/application.html.haml b/app/views/layouts/application.html.haml
index 95fb77f1..d6ad6ae6 100644
--- a/app/views/layouts/application.html.haml
+++ b/app/views/layouts/application.html.haml
@@ -7,6 +7,7 @@
     %meta{content: '', name: 'author'}
     = stylesheet_link_tag "application", media: 'all'
     = javascript_include_tag "application"
+    = auto_discovery_link_tag(:rss, feed_url(format: :rss), title: "#{ENV.fetch('OSEM_NAME', 'OSEM')} Conferences RSS Feed")
 
     = csrf_meta_tags
     = content_for(:script_head)
diff --git a/config/routes.rb b/config/routes.rb
index 730d43cf..2bc55e48 100644
--- a/config/routes.rb
+++ b/config/routes.rb
@@ -216,6 +216,7 @@ Osem::Application.routes.draw do
   get '/admin' => redirect('/admin/conferences')
 
   get '/calendar' => 'conferences#calendar'
+  get '/feed' => 'conferences#feed'
 
   if ENV.fetch('OSEM_ROOT_CONFERENCE', nil)
     root to: redirect("/conferences/#{ENV.fetch('OSEM_ROOT_CONFERENCE')}")