# Lustre

A framework for building create web apps – powered by Gleam and React!

---

[![Package Version](https://img.shields.io/hexpm/v/lustre)](https://hex.pm/packages/lustre)
[![Hex Docs](https://img.shields.io/badge/hex-docs-ffaff3)](https://hexdocs.pm/lustre/)

```gleam
import gleam/int
import lustre
import lustre/element.{ button, div, p, text }
import lustre/event.{ dispatch, on_click }

pub fn main () {
    let app = lustre.application(0, update, render)
    lustre.start(app, "#app")
}

type Action {
    Incr
    Decr
}

fn update (state, action) {
    case action {
        Incr -> state + 1
        Decr -> state - 1
    }
}

fn render (state) {
    div([], [
        button([ on_click(dispatch(Decr)) ], [ text("-") ]),
        p([], [ text(int.to_string(state)) ]),
        button([ on_click(dispatch(Incr)) ], [ text("+") ])
    ])
}
```

---

❗️ This package relies on Gleam's JavaScript FFI and is intended to be run in
the browser. **It will not work if your are targetting Node.js or Erlang.**

---

## Installation

If available on Hex, this package can be added to your Gleam project:

```sh
gleam add lustre
```

and its documentation can be found at <https://hexdocs.pm/lustre>. You will also
need to install `react` and `react-dom` from npm:

```sh
npm i react react-dom
```

---

## Development

First, make sure you have both Gleam and Node.js installed, then:

```bash
npm i
npm start
```

This sets up `chokidar` to watch our gleam source code and runs the compiler
whenever we make a change. It also starts a server that will serve the examples
located in `test/example/`.