What is the right way to embed image into email using Rails?

Solution 1:

I combined the answer from Oksana with a custom helper approach and got the following to work quite nicely.

app/helpers/email_helper.rb

module EmailHelper
  def email_image_tag(image, **options)
    attachments[image] = File.read(Rails.root.join("app/assets/images/#{image}"))
    image_tag attachments[image].url, **options
  end
end

app/mailers/base_mailer.rb

class BaseMailer < ActionMailer::Base
  add_template_helper(EmailHelper)
end

app/mailers/my_mailer.rb

class MyMailer < BaseMailer

  def send_my_mail(email)  
    mail to: email, subject: "My Subject"
  end
end

Then for example where I want to attach the company logo in my email layout file I would use

app/views/layouts/email.html.erb

<%= email_image_tag("company_logo.png") %>

Note the **options makes the tag more extensible but it will only work in ruby >=2. To make this work in ruby < 2 you will have to use the older way of handling key word options.

Solution 2:

RAILS 5

In your mail method add your inline attachment pointing to your image:

class ConfirmationMailer < ActionMailer::Base
  def confirmation_email
      attachments.inline["logo.png"] = File.read("#{Rails.root}/app/assets/images/logo.png")
      mail(to: email, subject: 'test subject')
  end
end

Then in your mail html view an image_tag with the attachment url:

<%= image_tag(attachments['logo.png'].url) %>

Solution 3:

Adding onto Oksana and tdubs' answers

The module tdubs wrote works on desktop, but for the mobile gmail client, the images appeared as attachments. To fix this, do this for the

app/helpers/email_helper.rb

module EmailHelper
    def email_image_tag(image, **options)
        attachments[image] = {
            :data => File.read(Rails.root.join("app/assets/images/emails/#{image}")),
            :mime_type => "image/png",
            :encoding => "base64"
        }
        image_tag attachments[image].url, **options
    end
end

For the rest, follow tdubs's answer.

Solution 4:

After a lot of research i have found very cleaner way to embed image in email. Just add following line in production.rb and development.rb

config.action_mailer.asset_host = 'YOUR HOST URL'

In your view embed image by using following code.

<%= image_tag('My Web Site Logo.png') %>

Note: Make sure to update YOUR HOST URL and My Web Site Logo.png in above code.

For basic details of usage of Action Mailer, please refer to ActionMailer::Base.