Offer to download QR codes in a ZIP archive

app/controllers/contestants_controller.rb

@@ -1,8 +1,10 @@
+require "zip"
+
 class ContestantsController < ApplicationController
   include CompletionsConcern
   include ContestantsConcern
 
-  before_action :set_contest, only: %i[ index edit new create update destroy import upload_csv convert_csv finalize_import export generate_qrcodes generate_qrcodes_pdf ]
+  before_action :set_contest, only: %i[ index edit new create update destroy import upload_csv convert_csv finalize_import export generate_qrcodes generate_qrcodes_pdf generate_qrcodes_archive ]
   before_action :set_contestant, only: %i[ destroy edit update]
   before_action :set_completions, only: %i[edit update ]
   skip_before_action :require_authentication, only: %i[ get_public_completion post_public_completion public_completion_updated ]
@@ -140,6 +142,24 @@ class ContestantsController < ApplicationController
     end
   end
 
+  def generate_qrcodes_archive
+    authorize @contest
+
+    generate_contestants_qrcodes(@contest)
+
+    @contestants = @contest.contestants.sort_by { |contestant| contestant.name }
+
+    stringio = Zip::OutputStream.write_buffer do |zio|
+      @contestants.each do |contestant|
+        zio.put_next_entry("#{@contest.friendly_id}_#{contestant.name}.svg")
+        zio.write contestant.qrcode
+      end
+    end
+    binary_data = stringio.string
+
+    send_data binary_data, filename: "#{@contest.friendly_id}_qrcodes.zip", disposition: "attachment"
+  end
+
   def get_public_completion
     skip_authorization
 

app/policies/contest_policy.rb

@@ -119,6 +119,10 @@ class ContestPolicy < ApplicationPolicy
     owner_or_admin
   end
 
+  def generate_qrcodes_archive?
+    owner_or_admin
+  end
+
   def upload_csv?
     owner_or_admin
   end

app/views/contestants/generate_qrcodes.html.slim

@@ -7,6 +7,8 @@
 
     a.mt-3.mb-3.btn.btn-primary href="#{contest_generate_qrcodes_pdf_path(@contest)}" target="_blank" style="margin-top: -3px"
       = t("helpers.buttons.open_raw")
+    a.mt-3.mb-3.ms-3.btn.btn-primary href="#{contest_generate_qrcodes_archive_path(@contest)}" target="_blank" style="margin-top: -3px"
+      = t("helpers.buttons.download_qrcodes_archive")
   
     .col.d-flex.flex-column style="height: calc(100% - 200px)"
       .d-flex.flex-column style="overflow-y: auto;"