Stylesheet inlining and plain text template generation for your email templates.


Keywords
css, elixir, elixir-lang, email, smoothie, stylesheets
License
MIT

Documentation

Smoothie

Stylesheet inlining and plain text template generation for your email templates.

Follow the installation instructions to set up Smoothie. After that we can use it in the following way in our project:

Let's suppose we are using the excellent Mailgun library to send our emails. Then we set up a Mailer module in the following location: web/mailers/mailer.ex, with the following content:

defmodule MyApp.Mailer do
  # your mailgun config here
  @config %{...}
  use Mailgun.Client, @config

  def welcome_email(user) do
    send_email to: user.email_address,
               from: "support@acme.com",
               subject: "Welcome!",
               text: "Welcome #{user.name}"
    :ok
  end
end

Pretty boring right. So lets add smoothie. First we need a layout, lets try this one (save as: web/mailers/templates/layouts/main.html.eex):

<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="utf-8">
  <meta name="viewport" content="width=device-width">
  <style type="text/css">
    @media screen and (min-width: 581px) {
      .container {
        width: 580px !important;
      }
    }
  </style>
</head>
<body>
  <table class="body-wrap">
    <tr>
      <td class="container">
        <table>
          <tr>
            <td align="center" class="masthead">
              <h1><%= @title %></h1>
            </td>
          </tr>
          <tr>
            <td class="content">
              {content}
            </td>
          </tr>
        </table>
      </td>
    </tr>
    <tr>
      <td class="container">
        <table>
          <tr>
            <td class="content footer" align="center">
              <p>Sent by <a href="http://www.acme.com">Acme</a></p>
              <p><a href="mailto:hello@acme.com">hello@acme.com</a></p>
            </td>
          </tr>
        </table>
      </td>
    </tr>
  </table>
</body>
</html>

Also, lets add a stylesheet. We can use sass for this! save in web/mailers/templates/layout/style.scss. If you just want to use css you can save it as style.css.

$action-color: #50E3C2;

@media only screen and (min-device-width: 581px) {
  .container {
    width: 580px !important;
  }
}


// Global
* {
  margin: 0;
  padding: 0;
  font-size: 100%;
  font-family: 'Avenir Next', "Helvetica Neue", "Helvetica", Helvetica, Arial, sans-serif;
  line-height: 1.65;
}

img {
  max-width: 100%;
  margin: 0 auto;
  display: block;
}

body,
.body-wrap {
  width: 100% !important;
  height: 100%;
  background: #efefef;
  -webkit-font-smoothing:antialiased;
  -webkit-text-size-adjust:none;
}

a {
  color: $action-color;
  text-decoration: none;
}

.text-center {
  text-align: center;
}

.text-right {
  text-align: right;
}

.text-left {
  text-align: left;
}

// Button
.button {
  display: inline-block;
  color: white;
  background: $action-color;
  border: solid $action-color;
  border-width: 10px 20px 8px;
  font-weight: bold;
  border-radius: 4px;
}

// Typography
h1, h2, h3, h4, h5, h6 {
  margin-bottom: 20px;
  line-height: 1.25;
}
h1 {
  font-size: 32px;
}
h2 {
  font-size: 28px;
}
h3 {
  font-size: 24px;
}
h4 {
  font-size: 20px;
}
h5 {
  font-size: 16px;
}

p, ul, ol {
  font-size: 16px;
  font-weight: normal;
  margin-bottom: 20px;
}

// layout
.container {
  display: block !important;
  clear: both !important;
  margin: 0 auto !important;
  max-width: 580px !important;

  table {
    width: 100% !important;
    border-collapse: collapse;
  }

  .masthead {
    padding: 80px 0;
    background: #50E3C2;
    color: white;

    h1 {
      margin: 0 auto !important;
      max-width: 90%;
      text-transform: uppercase;
    }
  }

  .content {
    background: white;
    padding: 30px 35px;

    &.footer {
      background: none;

      p {
        margin-bottom: 0;
        color: #888;
        text-align: center;
        font-size: 14px;
      }

      a {
        color: #888;
        text-decoration: none;
        font-weight: bold;
      }
    }
  }
}

Now create the template for our email, we can save this in web/mailers/templates/welcome.html.eex

Optionally adding additional css styling specific for this template partial is possible using <style> </style> tags.

<style>
    .inner-template{
        font-size: 120%;
        color: lightgreen;
    }
</style>

<h2>Hi <%= @name %>,</h2>

<p class="inner-template">Welcome!</p>

<p>Cheers,</p>

<p><em>—The Acme</em></p>

Alright we're all set up, lets make sure this template works in Smoothie:

defmodule MyApp.Mailer do
  # your mailgun config here
  @config %{...}
  use Mailgun.Client, @config
  use Smoothie,
    template_dir: "templates",
    layout_file: Path.join("layouts", "main.html.eex")



  def welcome_email(user) do
    template_params = [
      title: "Big Welcome!",
      name: user.name,
    ]

    send_email to: user.email_address,
               from: "support@acme.com",
               subject: "Welcome!",
               text: welcome_text(template_params),
               html: welcome_html(template_params)
    :ok
  end
end

Additionally to enable smoothie compilation on this module we need to add the module to the configuration (config/config.exs):

config :smoothie, modules: [MyApp.Mailer]

The last thing to do is to compile the templates, we need to do this every time when we change the templates or the layout:

> mix smoothie.compile
Preparing to compile the following template files:
- welcome.html.eex
Created welcome.html.eex
Created welcome.txt.eex
Done 🙏

Done! Now we are able to send very beautifully styled templates with styles inlined so it works in every email client, and for we also have a nice plain text version of the email!

Text templates

Smoothie automatically generates txt.eex templates from your html.eex files. If you don't like them, you can provide your own txt.eex templates by saving them to the same directory as your html.eex files.

/build
/layout
welcome.html.eex
welcome.txt.eex

To skip generating text templates altogether, set :html_only in your config,

config :smoothie, html_only: true

or run mix smoothie.compile --html-only.

Installation

Smoothie can be installed as:

  1. Add smoothie to your list of dependencies in mix.exs:
def deps do
  [{:smoothie, "~> 3.0"}]
end
  1. Ensure smoothie is started before your application:
def application do
  [applications: [:smoothie]]
end
  1. The only thing left is install the npm package that smoothie relies on in your project, we can do this with the following command:
  > mix smoothie.init

Compile with layout

  > mix smoothie.compile

Smoothie needs to install a npm library to do the css inlining, so make sure you have npm initialized in your project (a package.json file in your project's root)

Tests

yarn install && mix test

TODO

  • Create example usage repository (and link to README)