How to serve a vcard properly from amazon s3 in a rails app

_readme.md

This gist shows how to download a vcard with mime-type

It's easy to provide a simple link to download a vcard. The problem is that normal devices doesn't recognize the downloaded vcard and will most often just render them in the browser as plain text.

This gist is an example of how you can download the vcard with proper mime-type, which allows the device to recognize it as a vcard.

Prerequisites

This example assumes that you have a model Contact with a connected vcard. This example was built using a simple carrierwave uploader to upload the vcard to amazon s3.

my_controller.rb

# app/controllers/my_controller.rb

def download_vcard
  respond_to do |format|
    format.vcf do
      contact = Contact.find_by_id(params[:id]) # Find the contact that's requested
      return if contact.nil?                    # Make sure that the contact exists
      tmp_file = open(contact.vcard.url)        # This is needed to read the file from amazon (or any other remote url)
      send_data tmp_file.read, :filename => contact.name.parameterize, :type => :vcf # Send the actual file with proper mime-type
    end
  end
end

my_initializer.rb

# config/initializers/my_initializer.rb

Mime::Type.register 'text/x-vcard', :vcf  # Add the mime-type for vcards

my_view.html.erb

# app/views/my_controller/my_view.html.erb

<%= link_to("download vcard",  download_vcard_path(contact.id, :format => 'vcf'))  %>

routes.rb

# config/routes.rb

match 'vcard/:id',  to: 'my_controller#download_vcard', :as => :download_vcard