Rails is great at generating HTML, so of course ActionMailer can generate HTML. It works almost like generating text messages, but with a few more details. Because some users really prefer text email messages, this demonstration will give them a choice. The form in app/views/awards/show.html.erb used to request the email, previously shown in Example 17-5, will have an extra checkbox. This extra component sets a parameter identifying whether to send “rich text” (really HTML) email, highlighted in Example 17-6. (This code is in ch17/student011.)

<% form_tag email_student_award_path(@student, @award) do %>
  <p><%= check_box_tag :use_html %>
  <label for="use_html">Use rich text?</label></p>
  <%= submit_tag 'Email me this award' %>
<% end %>

The email method in awards_controller, previously shown in Example 17-2, grows a little more complex to support the checkbox’s new :use_html parameter, as shown in Example 17-7.

def email
    @award = @student.awards.find(params[:id])
    if params[:use_html]
      AwardMailer.deliver_html_certificate(@award, current_user.email)
    else
      AwardMailer.deliver_certificate(@award, current_user.email)
    end
    flash[:notice] = "Email has been sent"
    redirect_to([@student, @award])
  end

If the checkbox was checked, the user wants rich text, and so the controller calls AwardMailer’s deliver_html_certificate method instead of just deliver_certificate. There still isn’t really a deliver_html_certificate method in the app/models/award_mailer.rb file shown in Example 17-8, but there is a new html_certificate method that looks almost like the certificate method from Example 17-3, except that it has a different name and one new field.

def html_certificate(award, email)
    subject       award.name
    recipients    email
    from          'School System <[email protected]>'
    sent_on       Time.now
    body          :award => award
    content_type  'text/html'
end

The new content_type field is critical if you want the HTML to be rendered in the recipient’s mail view rather than show its source. By default, content_type will be text/plain, a MIME content type identifier that tells the mailer to render as text. Setting it to text/html tells the mailer to render as HTML. Of course, that means creating a view that will generate HTML, the /app/views/award_mailer/html_certificate.html.erb file shown in Example 17-9.

<table width="100%" border="1" cellpadding="10">
  <tr>
    <td align="center">
      <br />
      <br />
      <h1><%=h @award.name %></h1>
      <br />
      <br />
      <p>awarded to</p>
      <br />
      <br />
      <h2><%=h @award.student.name %></h2>
      <br />
      <h3><%=h @award.year %></h3
    </td>
  </tr>
</table>
<br />
<br />
<hr />

<p>Courtesy of the School System!</p>

Now, if users visit an award page, they’ll see a checkbox and button like that shown in Figure 17-5, from which they can send a message like that shown in Figure 17-6.

The HTML email sent will also be recorded in the log.

Figure 17-5. An extra option for sending awards email

Figure 17-6. A fancier award message