README.md

# Turboprop

[![Hex.pm](https://img.shields.io/hexpm/v/turboprop)](https://hex.pm/packages/turboprop)
[![npm](https://img.shields.io/npm/v/@leuchtturm/turboprop)](https://npmjs.com/package/@leuchtturm/turboprop)
[![Documentation](https://img.shields.io/badge/documentation-gray)](https://hexdocs.pm/turboprop/)

<p align="center">
  <img src="https://github.com/leuchtturm-dev/turboprop/raw/main/assets/turboprop.png" width="300" />
</p>

A toolkit to build beautiful, accessible components for Phoenix using Tailwind and Zag.

## State

This project is still at version `0.1` and should not be used in production as here still is a lot of documentation going on.

- The Turboprops Hook API will most definitely change, and the amount of hooks currently available is very limited. In addition to that,
they might not be fully documented or lack options.
- The Turboprop Merge API is considered stable, but it lacks the ability to configure it with custom Tailwind themes and the documentation
is considered work in progress.

## Contributing

While this project is at `0.1` and still a highly experimental playground, we are not looking for contributions. Once the API is a little
more stable and the project takes shape, this will of course change!

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## Installation

Simply add the `turboprop` library to your `mix.exs`:

`{:turboprop, "~> 0.2"}`

In addition, since Turboprop heavily utilises caching, its cache needs to be added to the supervision tree. In a default Phoenix
application, this is inside `application.ex`.

```elixir
children = [
  # ...
  Turboprop.Cache
  # ...
]
```

## Tools

Turboprop consists of multiple tools, each with their own purpose in building your component library.

### Turboprop Hooks

Turboprop Hooks allow adding a ton of accessibility features to your components by simply adding a hook and a few data attributes to them.  
This includes:

- Keyboard interactions
- Focus management
- ARIA attributes

You can either install and use them through the hex.pm dependency and some helpers we offer to add the relevant attributes to a component,
or install them directly through npm and adding the attributes yourself.  

As an example, this renders a fully accessible dropdown menu:

```heex
<div {menu()}>
  <button
    class="rounded-md bg-blue-500 px-3 py-1.5 text-sm text-white shadow-sm hover:bg-blue-400 focus-visible:outline focus-visible:outline-2 focus-visible:outline-offset-2 focus-visible:outline-blue-500"
    {menu_trigger()}
  >
    Menu
  </button>
  <div {menu_positioner()}>
    <div
      class="z-10 w-48 text-sm origin-top-right rounded-md bg-white py-1 shadow-lg ring-1 ring-black ring-opacity-5 focus:outline-none"
      {menu_content()}
    >
      <Phoenix.Component.link navigate="/link" class="block px-4 py-2 outline-0 data-[highlighted]:bg-gray-100" {menu_item()}>
        Link
      </Phoenix.Component.link>
      <a href="/anchor" id="test" class="block px-4 py-2 outline-0 data-[highlighted]:bg-gray-100" {menu_item()}>Anchor</a>
    </div>
  </div>
</div>
```

### Turboprop Merge

Turboprop Merge allows you to easily merge a list of Tailwind Classes to avoid style conflicts.

Imagine this component:

```elixir
attr :class, :string, doc: "Class override"
def button(assigns) do
  ~H"""
  <button class={["bg-black px-3 py-1.5 text-sm", @class]}>Click me!</button>
  """
end
```

And imagine wanting to make the text a little bigger as a one-off. You've already added a `@class` attribute, but rendering the component
with `class="text-lg"` will lead to an HTML output of `"bg-black px-3 py-1.5 text-sm text-lg"`, with two competing font size classes.

Now, replace the `class` attribute with `class={merge(["bg-black px-3 py-1.5 text-sm", @class])}` and you will magically get
`"bg-black px-3 py-1.5 text-lg"`.

### Turboprop Variants

Turboprop Variants is a variant API for TailwindCSS and Phoenix.

```elixir
def button() do
  %{
    base: "inline-flex items-center justify-center whitespace-nowrap rounded-md text-sm font-medium transition-colors focus-visible:outline-none focus-visible:ring-1 focus-visible:ring-ring disabled:pointer-events-none disabled:opacity-50",
    variants: %{
      variant: %{
        default: "bg-primary text-primary-foreground shadow hover:bg-primary/90",
        destructive: "bg-destructive text-destructive-foreground shadow-sm hover:bg-destructive/90",
        outline: "border border-input bg-background shadow-sm hover:bg-accent hover:text-accent-foreground",
        secondary: "bg-secondary text-secondary-foreground shadow-sm hover:bg-secondary/80",
        ghost: "hover:bg-accent hover:text-accent-foreground",
        link: "text-primary underline-offset-4 hover:underline"
      },
      size: %{
        default: "h-9 px-4 py-2",
        sm: "h-8 rounded-md px-3 text-xs",
        lg: "h-10 rounded-md px-8",
        icon: "h-9 w-9"
      }
    },
    default_variants: [
      variant: "default",
      size: "default"
    ]
  }
end

def render(assigns) do
  ~H"""
  <button class={variant(button(), variant: "outline", size: "lg")}>A large, outlined button</button>
  """
end
```

It supports variants, boolean variants, default variants, compound variants, slots, compound slots and more.

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