Persist event registration slugs in session

app/controllers/concerns/event_registration_session.rb

@@ -0,0 +1,19 @@
+module EventRegistrationSession
+  extend ActiveSupport::Concern
+
+  private
+
+  def store_event_reg_slug(event_id, slug)
+    session[:event_reg_slugs] ||= {}
+    session[:event_reg_slugs][event_id.to_s] = slug
+  end
+
+  def clear_event_reg_slug(event_id)
+    return unless session[:event_reg_slugs]
+    session[:event_reg_slugs].delete(event_id.to_s)
+  end
+
+  def event_reg_slug_for(event_id)
+    session.dig(:event_reg_slugs, event_id.to_s)
+  end
+end

app/controllers/events/public_registrations_controller.rb

@@ -1,5 +1,6 @@
 module Events
   class PublicRegistrationsController < ApplicationController
+    include EventRegistrationSession
     skip_before_action :authenticate_user!, only: [ :new, :create, :show ]
     before_action :set_event
     before_action :ensure_registerable, only: [ :new, :create ]
@@ -53,6 +54,7 @@ def create
       )
 
       if result.success?
+        store_event_reg_slug(@event.id, result.event_registration.slug)
         redirect_to registration_ticket_path(result.event_registration.slug),
                     notice: "You have been successfully registered!"
       else

app/controllers/events/registrations_controller.rb

@@ -1,12 +1,14 @@
 module Events
   class RegistrationsController < ApplicationController
+    include EventRegistrationSession
     before_action :authenticate_user!, only: [ :create, :destroy ]
     before_action :set_event, only: [ :create, :destroy ]
     before_action :set_registrant, only: [ :create, :destroy ]
     before_action :set_event_registration, only: [ :show, :resend_confirmation, :cancel, :reactivate ]
 
     def show
       authorize! @event_registration, to: :show_public?
+      store_event_reg_slug(@event_registration.event_id, @event_registration.slug) if @event_registration.active?
     end
 
     def resend_confirmation
@@ -20,6 +22,7 @@ def cancel
 
       if @event_registration.active?
         @event_registration.update!(status: "cancelled")
+        clear_event_reg_slug(@event_registration.event_id)
         redirect_to registration_ticket_path(@event_registration.slug), notice: "Your registration has been cancelled."
       else
         redirect_to registration_ticket_path(@event_registration.slug), alert: "Registration is already cancelled."
@@ -31,6 +34,7 @@ def reactivate
 
       if @event_registration.status == "cancelled"
         @event_registration.update!(status: "registered")
+        store_event_reg_slug(@event_registration.event_id, @event_registration.slug)
         redirect_to registration_ticket_path(@event_registration.slug), notice: "Your registration has been reactivated."
       else
         redirect_to registration_ticket_path(@event_registration.slug), alert: "Registration is not cancelled."
@@ -43,6 +47,7 @@ def create
       if existing&.status == "cancelled"
         authorize! existing
         existing.update!(status: "registered")
+        store_event_reg_slug(@event.id, existing.slug)
         success = "Your registration has been reactivated."
         respond_to do |format|
           format.turbo_stream { flash.now[:notice] = success }
@@ -55,6 +60,7 @@ def create
       authorize! @event_registration
 
       if @event_registration.save
+        store_event_reg_slug(@event.id, @event_registration.slug)
         success = "You have successfully registered for this event."
         respond_to do |format|
           format.turbo_stream { flash.now[:notice] = success }

app/controllers/events_controller.rb

@@ -1,5 +1,5 @@
 class EventsController < ApplicationController
-  include AhoyTracking, TagAssignable
+  include AhoyTracking, TagAssignable, EventRegistrationSession
   skip_before_action :authenticate_user!, only: [ :index, :show ]
   skip_before_action :verify_authenticity_token, only: [ :preview ]
   before_action :set_event, only: %i[ show edit update destroy preview manage copy_registration_form ]
@@ -8,12 +8,14 @@ def index
     authorize!
     base_scope = authorized_scope(Event.all)
     @events  = base_scope.search_by_params(params).order(start_date: :desc)
+    persist_reg_slug_from_params
   end
 
   def show
     authorize! @event
     @event = @event.decorate
     track_view(@event)
+    persist_reg_slug_from_params
   end
 
   def new
@@ -228,6 +230,12 @@ def set_event
     @event = Event.find(params[:id])
   end
 
+  def persist_reg_slug_from_params
+    return unless params[:reg].present?
+    reg = EventRegistration.find_by(slug: params[:reg])
+    store_event_reg_slug(reg.event_id, reg.slug) if reg&.active?
+  end
+
   def event_params
     params.require(:event).permit(:cost,
                                   :created_by_id,

app/views/events/_card.html.erb

@@ -30,6 +30,11 @@
 
   <!-- Location + Times + Buttons (bottom-aligned group) -->
   <% registered = current_user && event.actively_registered?(current_user.person) %>
+  <% unless registered
+       reg_slug = session.dig(:event_reg_slugs, event.id.to_s)
+       slug_registration = reg_slug ? EventRegistration.find_by(slug: reg_slug, event_id: event.id) : nil
+       slug_registered = slug_registration&.active?
+     end %>
   <div class="mt-auto flex flex-col gap-4">
     <div class="text-sm text-gray-700 leading-none">
       <% if event.location.present? %>
@@ -55,6 +60,11 @@
                   data: { turbo_frame: "_top" },
                   class: "btn px-3 py-2 text-xs uppercase leading-tight text-white hover:bg-white event-view-registration-btn",
                   style: "font-family: 'Telefon Bold', sans-serif; background-color: rgb(22, 101, 52); border: 2px solid rgb(22, 101, 52);" %>
+    <% elsif slug_registered %>
+      <%= link_to "View registration", registration_ticket_path(slug_registration.slug),
+                  data: { turbo_frame: "_top" },
+                  class: "btn px-3 py-2 text-xs uppercase leading-tight text-white hover:bg-white event-view-registration-btn",
+                  style: "font-family: 'Telefon Bold', sans-serif; background-color: rgb(22, 101, 52); border: 2px solid rgb(22, 101, 52);" %>
     <% elsif event.ended? %>
       <span class="text-sm text-gray-500 italic">Event ended</span>
       <% if allowed_to?(:manage?, event) %>

app/views/events/_registration_section.html.erb

@@ -1,7 +1,8 @@
 <% instance ||= 1 %>
 <% button_text ||= "Register" %>
 <% registered = event.actively_registered?(current_user&.person) %>
-<% slug_registration = params[:reg].present? ? EventRegistration.find_by(slug: params[:reg], event_id: event.id) : nil %>
+<% reg_slug = params[:reg].presence || session.dig(:event_reg_slugs, event.id.to_s) %>
+<% slug_registration = reg_slug ? EventRegistration.find_by(slug: reg_slug, event_id: event.id) : nil %>
 <% slug_registered = slug_registration&.active? %>
 <% slug_cancelled = slug_registration.present? && slug_registration.status == "cancelled" %>
 <%= tag.div id: dom_id(event.object, "registration_section_#{instance}"), class: "registration-section flex flex-col items-center gap-4 mb-6" do %>

app/views/events/show.html.erb

@@ -8,10 +8,11 @@
 <% else %>
 <!-- Top Right Actions -->
 <div class="flex flex-wrap items-center gap-2 mb-4">
-  <%= link_to "← Back to Events", events_path, class: "text-sm text-gray-500 hover:text-gray-700 px-2 py-1" %>
+  <% reg_slug = params[:reg].presence || session.dig(:event_reg_slugs, @event.id.to_s) %>
+  <%= link_to "← Back to Events", events_path(reg: reg_slug), class: "text-sm text-gray-500 hover:text-gray-700 px-2 py-1" %>
   <div class="ml-auto flex flex-wrap gap-2">
   <%= link_to "Home", root_path, class: "text-sm text-gray-500 hover:text-gray-700 px-2 py-1" %>
-  <%= link_to "Events", events_path, class: "text-sm text-gray-500 hover:text-gray-700 px-2 py-1" %>
+  <%= link_to "Events", events_path(reg: reg_slug), class: "text-sm text-gray-500 hover:text-gray-700 px-2 py-1" %>
   <% if allowed_to?(:manage?, @event) && @event.object.event_forms.registration.exists? %>
     <%= link_to "Register (as visitor)", new_event_public_registration_path(@event), class: "text-sm text-gray-500 hover:text-gray-700 px-2 py-1 admin-only bg-blue-100" %>
   <% end %>

spec/requests/events/registrations_spec.rb

@@ -18,6 +18,20 @@
         get registration_ticket_path(registration.slug)
         expect(response).to have_http_status(:success)
       end
+
+      it "stores the slug in session for active registrations" do
+        get registration_ticket_path(registration.slug)
+        expect(session[:event_reg_slugs]).to eq({ event.id.to_s => registration.slug })
+      end
+    end
+
+    context "when the registration is cancelled" do
+      before { registration.update!(status: "cancelled") }
+
+      it "does not store the slug in session" do
+        get registration_ticket_path(registration.slug)
+        expect(session[:event_reg_slugs]).to be_nil
+      end
     end
 
     context "as an admin" do
@@ -91,6 +105,15 @@
       expect(flash[:notice]).to eq("Your registration has been cancelled.")
     end
 
+    it "clears the slug from session" do
+      # First store the slug via show
+      get registration_ticket_path(registration.slug)
+      expect(session[:event_reg_slugs][event.id.to_s]).to eq(registration.slug)
+
+      post registration_cancel_path(registration.slug)
+      expect(session[:event_reg_slugs][event.id.to_s]).to be_nil
+    end
+
     it "does not cancel an already cancelled registration" do
       registration.update!(status: "cancelled")
 
@@ -123,6 +146,11 @@
       expect(flash[:notice]).to eq("Your registration has been reactivated.")
     end
 
+    it "stores the slug in session after reactivation" do
+      post registration_reactivate_path(registration.slug)
+      expect(session[:event_reg_slugs]).to eq({ event.id.to_s => registration.slug })
+    end
+
     it "does not reactivate an already active registration" do
       registration.update!(status: "registered")
 
@@ -193,6 +221,12 @@
         expect(response.media_type).to eq("text/vnd.turbo-stream.html")
         expect(flash.now[:notice]).to eq("You have successfully registered for this event.")
       end
+
+      it "stores the slug in session" do
+        post event_registrant_registration_path(event_id: event.id)
+        reg = EventRegistration.last
+        expect(session[:event_reg_slugs]).to eq({ event.id.to_s => reg.slug })
+      end
     end
 
     context "when a cancelled registration exists" do
@@ -218,6 +252,11 @@
         expect(response).to redirect_to(registration_ticket_path(cancelled_registration.slug))
         expect(flash[:notice]).to eq("Your registration has been reactivated.")
       end
+
+      it "stores the slug in session on reactivation" do
+        post event_registrant_registration_path(event_id: event.id)
+        expect(session[:event_reg_slugs]).to eq({ event.id.to_s => cancelled_registration.slug })
+      end
     end
 
     context "when creation fails" do

spec/requests/events_spec.rb

@@ -29,6 +29,13 @@
       expect(response).to have_http_status(:ok)
     end
 
+    it "stores reg slug in session when reg param is present" do
+      sign_in user
+      registration = create(:event_registration, event: event, registrant: create(:person))
+      get events_path(reg: registration.slug)
+      expect(session[:event_reg_slugs]).to eq({ event.id.to_s => registration.slug })
+    end
+
     context "when user time_zone is set" do
       # 19:00 UTC = 12:00 noon PT = 15:00 (3 pm) ET (June 15, 2025 with DST)
       let(:utc_start) { Time.utc(2025, 6, 15, 19, 0, 0) }
@@ -63,6 +70,22 @@
     end
   end
 
+  describe "GET /show" do
+    it "stores reg slug in session when reg param is present" do
+      sign_in user
+      registration = create(:event_registration, event: event, registrant: create(:person))
+      get event_path(event, reg: registration.slug)
+      expect(session[:event_reg_slugs]).to eq({ event.id.to_s => registration.slug })
+    end
+
+    it "does not store slug for cancelled registrations" do
+      sign_in user
+      registration = create(:event_registration, event: event, registrant: create(:person), status: "cancelled")
+      get event_path(event, reg: registration.slug)
+      expect(session[:event_reg_slugs]).to be_nil
+    end
+  end
+
   describe "GET /new" do
     context "as admin" do
       it "renders successfully" do