MJML-Rails allows you to render HTML emails from an MJML template.
Note: As of MJML 4.3.0 you can no longer use <mj-text> directly inside an <mj-body>, wrap it in <mj-section><mj-column>.
An example template might look like:
<!-- ./app/views/user_mailer/user_signup_confirmation.mjml -->
<mjml>
<mj-head>
<mj-preview>Hello World</mj-preview>
</mj-head>
<mj-body>
<mj-section>
<mj-column>
<mj-text>Hello World</mj-text>
<%= render partial: "info", formats: [:html] %>
</mj-column>
</mj-section>
</mj-body>
</mjml>And the partial:
<!-- ./app/views/user_mailer/_info.html.erb -->
<mj-text>This is <%= @user.username %></mj-text>- Notice you can use ERB and partials inside the template.
Your user_mailer.rb might look like this:
# ./app/mailers/user_mailer.rb
class UserMailer < ActionMailer::Base
def user_signup_confirmation
mail(to: "[email protected]", from: "[email protected]") do |format|
format.text
format.mjml
end
end
end- MJML with Rails 6: Renders HTML emails with MJML layout, view, and partial.
Add it to your Gemfile.
gem 'mjml-rails'Run the following command to install it:
bundle installAdd the MJML parser to your project with your favourite package manager:
# with npm
npm install mjml
# or install it globally (The best way for Rails 7.x.x with importmaps)
npm install -g mjml
# with yarn
yarn add mjmlMJML-Rails falls back to a global installation of MJML but it is strongly recommended to add MJML directly to your project.
You'll need at least Node.js version 6 for MJML to function properly.
If for some reason you can't or don't want to run JS code in your production environment, you can use MRML. It ships with already compiled binaries for Rust implementation of MJML so it has no external dependencies.
Add mjml-rails and mrml to your Gemfile.
gem 'mjml-rails'
gem 'mrml'Run the following command to install it:
bundle installSet use_mrml option to true in your initializer:
# config/initializers/mjml.rb
Mjml.setup do |config|
config.use_mrml = true
endNote: MRML does not fully support all MJML functionalities, see Missing implementations
MJML-Rails has the following settings with defaults:
-
template_language: :erbERB can be used inside MJML templates by default. Possible values are all template languages that you have installed, e.g.
:hamlor:slim.Note: If you’re using Haml/Slim layouts, please don’t put
<mjml>in comments in your partial. Read more at #34. -
raise_render_exception: trueExceptions will be raised and passed to your application by default.
Beware that setting it to
falseleads to an empty html email when an exception is raised, so only set this tofalseif you do not rely on html (e.g. you have a text fallback for your emails). -
minify: false -
beautify: true -
validation_level: "strict"MJML-Rails will raise an exception on any template error by default.
If set to
soft, MJML will render invalid templates and ignore invalid parts. This means in case of an invalid template those invalid parts will be missing from the output.See MJML validation documentation for all possible values.
-
mjml_binary: nilThis can be used to specify the path to a custom MJML binary if it is not detected automatically (shouldn't be needed).
-
mjml_binary_version_supported: "4."MJML-Rails checks the version of the MJML binary and fails if it does not start with this version, e.g. if an old version is installed by accident.
-
use_mrml: falseEnabling this will allow you to use Rust implementation of MJML via themrmlgem. It comes with prebuilt binaries instead of having to install MJML along with Node. When enabled the optionsmjml_binary_version_supported,mjml_binary,minify,beautifyandvalidation_levelare ignored. -
fontsBy default, MJML-Rails uses MJML default fonts, but enables you to override it. Example :config.fonts = { Raleway: 'https://fonts.googleapis.com/css?family=Raleway }
# config/initializers/mjml.rb
Mjml.setup do |config|
# Use :haml as a template language
config.template_language = :haml
# Ignore errors silently
config.raise_render_exception = false
# Optimize the size of your emails
config.beautify = false
config.minify = true
# Render MJML templates with errors
config.validation_level = "soft"
# Use MRML instead of MJML, false by default
config.use_mrml = false
# Use custom MJML binary with custom version
config.mjml_binary = "/path/to/custom/mjml"
config.mjml_binary_version_supported = "3.3.5"
# Use default system fonts instead of google fonts
config.fonts = {}
endVersion 4.x of this gem brings support for MJML 4.x
Version 2.3.x and 2.4.x of this gem brings support for MJML 3.x
If you'd rather still stick with MJML 2.x then lock the mjml-rails gem:
gem 'mjml-rails', '2.2.0'For MJML 3.x lock the mjml-rails gem:
gem 'mjml-rails', '2.4.3'And then to install MJML 3.x
npm install -g [email protected]Kitty Giraudel wrote a post on using MJML in Rails.
Note: Aleksandrs Ļedovskis kindly updated the gem for better Rails Email Layouts support - it should be a non-breaking change, but check the updated file naming below if you experience problems.
Mailer:
# mailers/my_mailer.rb
class MyMailer < ActionMailer::Base
layout "default"
def foo_bar(user)
@recipient = user
mail(to: user.email, from: "[email protected]") do |format|
format.html # This will look for "default.html.erb" and then "default.html.mjml"
end
end
endNote: If default.html.erb exists, email will be rendered as ERB, and MJML tags will not be compiled.
Email layout:
<!-- views/layouts/default.html.mjml -->
<mjml>
<mj-body>
<%= yield %>
</mj-body>
</mjml>Email view:
<!-- views/my_mailer/foo_bar.html.mjml (or foo_bar.html.erb) -->
<%= render partial: "to" %>
<mj-section>
<mj-column>
<mj-text>
Something foo regarding bar!
</mj-text>
</mj-column>
</mj-section>Email partial:
<!-- views/my_mailer/_to.html.mjml (or _to.html.erb) -->
<mj-section>
<mj-column>
<mj-text>
Hello <%= @recipient.name %>,
</mj-text>
</mj-column>
</mj-section>If you use Devise for user authentication and want to send user emails with MJML templates, here's how to override the devise mailer:
# app/mailers/devise_mailer.rb
class DeviseMailer < Devise::Mailer
def reset_password_instructions(record, token, opts={})
@token = token
@resource = record
# Custom logic to send the email with MJML
mail(
template_path: 'devise/mailer',
from: "[email protected]",
to: record.email,
subject: "Custom subject"
) do |format|
format.text
format.mjml
end
end
endNow tell devise to user your mailer in config/initializers/devise.rb by setting config.mailer = 'DeviseMailer' or whatever name you called yours.
And then your MJML template goes here: app/views/devise/mailer/reset_password_instructions.mjml
Devise also have more instructions if you need them.
To deploy with Heroku you'll need to setup multiple buildpacks so that Heroku first builds Node for MJML and then the Ruby environment for your app.
Once you've installed the Heroku Toolbelt you can setup the buildpacks from the commandline:
$ heroku buildpacks:set heroku/ruby
And then add the Node buildpack to index 1 so it's run first:
$ heroku buildpacks:add --index 1 heroku/nodejs
Check that's all setup by running:
$ heroku buildpacks
Next you'll need to setup a package.json file in the root, something like this:
{
"name": "your-site",
"version": "1.0.0",
"description": "Now with MJML email templates!",
"main": "index.js",
"directories": {
"doc": "doc",
"test": "test"
},
"dependencies": {
"mjml": "^4.0.0"
},
"repository": {
"type": "git",
"url": "git+https://github.com/your-repo/your-site.git"
},
"keywords": [
"mailer"
],
"author": "Your Name",
"license": "ISC",
"bugs": {
"url": "https://github.com/sighmon/mjml-rails/issues"
},
"homepage": "https://github.com/sighmon/mjml-rails"
}Then $ git push heroku master and it should Just WorkTM.
If you discover any bugs, feel free to create an issue on GitHub. Please add as much information as possible to help us fixing the possible bug. We also encourage you to help even more by forking and sending us a pull request.
github.com/sighmon/mjml-rails/issues
- Simon Loffler github.com/sighmon
- Steven Pickles github.com/thatpixguy
- The Rails community. :-)
MIT License. Copyright 2018 Simon Loffler. sighmon.com
Lovingly built on github.com/plataformatec/markerb
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