openproject/app/views/common/list_attachments.json.erb

<%#-- copyright
OpenProject is an open source project management software.
Copyright (C) 2012-2021 the OpenProject GmbH

This program is free software; you can redistribute it and/or
modify it under the terms of the GNU General Public License version 3.

OpenProject is a fork of ChiliProject, which is a fork of Redmine. The copyright follows:
Copyright (C) 2006-2013 Jean-Philippe Lang
Copyright (C) 2010-2013 the ChiliProject Team

This program is free software; you can redistribute it and/or
modify it under the terms of the GNU General Public License
as published by the Free Software Foundation; either version 2
of the License, or (at your option) any later version.

This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
GNU General Public License for more details.

You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.

See COPYRIGHT and LICENSE files for more details.

++#%>

<%= attachments.select { |a| a.readable? and a.visible? }
               .map { |a| { content_type: CGI::escape_html(a.content_type),
                            filename:     CGI::escape_html(a.filename),
                            description:  CGI::escape_html(a.description),
                            url: url_for(controller: '/attachments', action: 'show', id: a, filename: a.filename),
                            is_image: !!a.image? # doing the !! as image? for whatever reason returns null or a number
                          }
                    }.to_json.html_safe %>