TechNewsletter

The engineering way 🤓 of composing a responsive design newsletter email 📰📧 in markup language.

Philosophy

Q: Why not to use any email marketing automation platform?

A: Drag and click? Come on, we're engineers, there is a better way. Limited features for editing? They have, but we don't. We offer free, open source software, with maximum flexibility for customization.

Q: Why do I name my custom markup language as .slm?

A: SLM (aka the English word slim) = Super Lightweight Markup. Isn't it sexy? 🤓 And for the tag delimiter, I've chosen ⇥⇤, which is rarely used in text content, it means slim as well, just imagine: ⇥)(⇤ it's so vivid!

Setup

• Run bundle install to install all necessary dependencies

HOWTO

Literally, there is no easier way than this one.

• Prepare your [source].slm

  • In custom markup language

  • No nonsense content (I mean HTML tags, CSS styles and etc.)

  • Indentation: 2 spaces (if you use tabs, alright, but it will be normalized to spaces anyway)

  • Please refer to this example

• [ Optional ] Add your own or modify existing HTML fragment inside templates directory

• [ Optional ] Add or modify corresponding *Printer class (which inherits Printer class) under printers directory. Including two major behavior:

  • Parsing the tree data structure from the custom markup language (.slm)

  • Rendering HTML fragment

• Run code to compile .slm to a fabulous HTML page

Test

To run unit test: rake test

Compatibility

To check the email client support of any specific HTML and CSS feature, please go and ask Can I email…

• External CSS: When you host the CSS file on GitHub (not GitHub Pages), even if you specify type="text/css", GitHub will respond the CSS file with MIME type text/plain, and your browser won't be able to render the CSS.

  • Chrome: Cross-Origin Read Blocking (CORB) blocked cross-origin response with MIME type text/plain.

  • Firefox: The resource was blocked due to MIME type (“text/plain”) mismatch (X-Content-Type-Options: nosniff).

  • Safari: Did not parse stylesheet because non CSS MIME types are not allowed when 'X-Content-Type: nosniff' is given.

  • Workaround: Route the CSS file hosted on GitHub via a free open source CDN such as jsDelivr, which will eventually respond it with the proper MIME type text/css. Just like this: <link rel="stylesheet" type="text/css" href="https://cdn.jsdelivr.net/gh/USERNAME/REPOSITORY/.../YOUR.CSS" />

• Inline CSS can not be rendered properly in some email clients.

• Embedded Image vs. Linked Image: For the sake of better support, this tool only uses linked image at the moment. To learn more details regarding the comparison, please read this.

• SVG is supported in some email clients, as stated here. Furthermore, depends on the way how you use it, the support behavior from the same client may change. Last, let's say at the moment Gmail blocks SVG by its proxy, but if you read the email in another client (e.g. Airmail), which links to your Gmail account, you could still view the SVG without any problem.

✅ Verified email clients:

• Gmail (Web, Android, iOS)

• Airmail (macOS)

• Apple Mail (macOS, iOS)

• Outlook (Web)

License

Copyright (c) 2016-2021 Jing Li. It is released under the MIT License. See the LICENSE file for details. Additionally, there is a hardcoded attribution at the bottom of the generated newsletter, just to give credit to my hard work.

Attribution

The social media icons used in this project are from Font Awesome licensed under CC BY 4.0 License.