MRML

Crates.io

Introduction

This project is a reimplementation of the nice MJML markup language in Rust.

How to use it in my code

Update your cargo.toml:

toml [dependencies] mrml = "1.2" serde = { version = "1.0", features = ["derive"] }

Create your main.rs:

```rust use mrml;

fn main() { let root = mrml::parse("").expect("parse template"); let opts = mrml::prelude::render::Options::default(); match root.render(&opts) { Ok(content) => println!("{}", content), Err(_) => println!("couldn't render mjml template"), }; } ```

Why?

A Node.js server rendering an MJML template takes around 20 MB of RAM at startup and 130 MB under stress test. In Rust, less than 1.7 MB at startup and a bit less that 3 MB under stress test. The Rust version can also handle twice as many requests per second. You can perform the benchmarks by running bash script/run-bench.sh.
The JavaScript implementation cannot be run in the browser; the Rust one (and WebAssembly one) can be.

You want to contribute?

Feel free to read our contributing section and the code of conduct.

Performance

With the same Linux amd64 machine, to render the amario template

Node: 606.59ms
Rust: 3.48ms

Missing implementations

mj-style[inline]: not yet implemented. It requires parsing the generated html to apply the inline styles afterward (that's how it's done in mjml) which would kill the performances. Applying it at render time would improve the performance but it would still require to parse the CSS.
mj-include: not yet implemented. It requires to handle loading remote templates when using mrml in a wasm (browser or server side) format, which implies being able to load from a different location (file://, https://, relative, etc).