Render calendar feed inline when accessed from GitLab47672-set_inline_content_type_for_ics

With text/calendar as Content-Type, the browser always downloads the
content as a file (even ignoring the Content-Disposition header). We
want to display the content inline when accessed from Gitlab, similarly
to the RSS feed.

1 files changed, 24 insertions, 0 deletions

diff --git a/app/controllers/concerns/issues_calendar.rb b/app/controllers/concerns/issues_calendar.rb
new file mode 100644
index 00000000000..96f6d1865e9
--- /dev/null
+++ b/app/controllers/concerns/issues_calendar.rb
@@ -0,0 +1,24 @@
+module IssuesCalendar
+  extend ActiveSupport::Concern
+
+  # rubocop:disable Gitlab/ModuleWithInstanceVariables
+  def render_issues_calendar(issuables)
+    @issues = issuables
+                  .non_archived
+                  .with_due_date
+                  .limit(100)
+
+    respond_to do |format|
+      format.ics do
+        # NOTE: with text/calendar as Content-Type, the browser always downloads
+        #       the content as a file (even ignoring the Content-Disposition
+        #       header). We want to display the content inline when accessed
+        #       from Gitlab, similarly to the RSS feed.
+        if request.referer&.start_with?(::Settings.gitlab.base_url)
+          response.headers['Content-Type'] = 'text/plain'
+        end
+      end
+    end
+  end
+  # rubocop:enable Gitlab/ModuleWithInstanceVariables
+end