marilena

Intro

We know emails are VERY HARD to develop from scratch. Sometimes you can use tool like Maiject, SendPulse, MailerSend, Stripo.email etc. Some of this have cool interfaces with drag and drop and different actions to do.

So why you/your company should use this library?

• you need to produce some html files using layouts and partials for different languages, passing them to a backend witch add maybe some data coming from itself (or another service) and fills your html files with its template engine.
• backend of your company deploy email using with a custom service that use Amazon SES.
• previous providers are not able to customize some parts. For example css rule. Or to do this is very complicated.
• coming from email-foundation-template and you want to try a different tool with advantages (please read below about features).
• having complete control of development without use any Saas is mandatory.

This project wants to mix up MJML, a template engine for variables and a web server, to create a tool able to generate emails with a simple flow and one command. Please keep in mind that Maiject, SendPulse, MailerSend, Stripo.email etc maybe can be already perfect for your purpose.

🚀 Usage

Install (require node >=16)

npm i marilena

Setup

marilena provides a command witch generate a small but working example with eta.js, variables, layout and partials. You can choose to generate this example adding these commands to your package.json and then run npm run generate-example.

"scripts": {
  "start": "marilena --server --project example/marilena.config.mjs",
  "build": "marilena --build --project example/marilena.config.mjs",
  "generate-example": "marilena --create-example",
},

Setup (manual)

If you fails to generate the example or you want to build a project from 0 you need to crete marilena.config.mjs file in the root of your project. Please check below the fields since any of these are required.

import path from "path";
// you can leverage your IDE's intellisense with jsdoc type hints
/** @type {import('marilena').UserConfig} */
export default {
  inputFolder: "./input",
  outputFolder: "./output",
  textVersion: (emailName, locale) => `${emailName}_text_version-${locale}.txt`,
  htmlVersion: (emailName, locale) => `${emailName}-custom.html`,
  locales: ["it", "en"],
  templateOptions: {
    engine: "eta",
    prepareEngine: (eta) => {
      eta.configure({
        views: path.join(process.cwd(), "playground/input"),
      });
    },
  },
  mjmlParsingOptions: {
    keepComments: false,
  },
};

Edit you package.json. By default marilena try to find config in the root of your project. If you put the config in a different path, you need to pass --project argument in the scripts

"scripts": {
  "start": "marilena --server",
  "build": "marilena --build",
},

create a file structures based on your config. Please remember that each email template requires index.html as name, and variables are loaded only from variables.json or variables.yml. Yes you can use both :)

project
| marilena.config.mjs
│ package.json
│ input
│ └──common-en.json // common json variables for all en emails
│ └──common-it.yaml // common yaml variables for all it emails
│ └──buy // email name
││││││└─── index.html
││││││└─── en
│││││││││││└── variables.json // json variables for en buy email
││││││└─── it
│││││││││││└── variables.yaml // yaml variables for it buy email

3 - fill your emails template with MJML syntax

<mjml>
  <mj-body>
    <mj-section>
      <mj-column>
        <!-- eta js example, read below about template engine -->
        <mj-text>hello <%= it.user %></mj-text>
      </mj-column>
    </mj-section>
  </mj-body>
</mjml>

4 - run one of these 2 commands

# open a server on http://localhost:8080
npm run start

# build all emails based on config
npm run build

Configuration

Under the hood a default configuration will be loaded but a file marilena.config.mjs allow us to set:

name	required	description	default
inputFolder		folder where email are in the project. Path is relative to marilena.config.mjs	./input
outputFolder		folder used for generated email (when run build command). Path is relative to marilena.config.mjs	./output
locales		array of languages used. If you need only spanish email use an array of single value	["es"]
templateOptions		if you chose to use one of supported engines, this part is mandatory to setup custom partial and other settings for the template engine selected. Read below for some use cases	empty
mjmlParsingOptions		options passed to mjml render. See: mjml options
htmlVersion		function of type (emailName: string, locale: string) => string. If set, this function allow to customize the output html filename. The function must return file name es: ${emailName}-${locale}.html	index.html
textVersion		function of type (emailName: string, locale: string) => string. If set, this function allow to generate text version of email stripping all html. The function must return file name es: ${emailName}-${locale}-text-version.txt

About templateOptions

This project can producte output html from input template. But in a real word probably we store variables in some part and render some content multiple times (example a footer). In this case templateOptions can define:

• engine: eta or handlebars are supported. Apart eta, which is used also in the project library, all others requires dependency installed since marilena use lazy import for engines.
• prepareEngine: define a callback where we can setup our engine. Basically you can define all things before the render. For example:

templateOptions: {
  engine:  "eta",
  prepareEngine: (eta) => {
    // eta is an istance of new Eta() so you need to set at least views options for templates/layout/partials
    eta.configure({
      views: path.join(process.cwd(), "input"),
    });
    // we can call all eta-js api like:
    eta.loadTemplate(...);
  },
},

templateOptions: {
  engine:  "handlebars",
  prepareEngine: (h) => {
    // we can register partial like:
    // handlebars is same of var h = require("handlebars");
    h.registerPartial("myPartial", "partial with {{ user }}");
  },
},

---

Use css

If you want to add a css file import in mj-include tag. Path start from root directory of the project (like package json):

<mjml>
  <mj-body>
    <mj-include path="input/styles.css" type="css" css-inline="inline"/>
    <!-- other mjml nodes -->
  </mj-body>
</mjml>

🚀 Features

• MJML support
• load variables with template engine
• multi language out of the box
• eta.js, handlebars (need to install if you use one of these engines)
• fast-refresh on variables changes
• fast-refresh on template change
• fast-refresh on css change
• load varibles from yaml/json format
• load common variables
• pass option to MJML render

🏗️ Roadmap (PRs are welcome 😀)

• liquid, ejs, nunjucks, mustache, dot
• config in typescript
• easy way to send a real email (AWS Ses/Nodemailer)
• fast-refresh on config change
• snaphost test for each email out of the box
• refactor to esm instead common js