Disclaimer: This is a fork of tailwind_fuse.

Rust UI Merge

Two main utils are included in this crate:

1. Fuse: Fuse multiple Tailwind classes, with optional conflict resolution.

   Inspired by Tailwind Merge

2. Variants: Compose type-safe variant classes

   Inspired by Class Variance Authority

Installation

Variants requires the variant feature to be enabled.

With variant

cargo add rustui_merge --features variant

Without variant

cargo add rustui_merge

Usage: Fuse

You can use [tw_join!] to join Tailwind classes, and [tw_merge!] to merge Tailwind Classes handling conflicts.

You can use anything that implements [AsTailwindClass]

use rustui_merge::*;

// No conflict resolution
assert_eq!(
   "flex items-center justify-center",
   tw_join!("flex", "items-center", "justify-center")
);

// Conflict resolution
// Right most class takes precedence
assert_eq!(
   "p-4",
   tw_merge!("py-2 px-4", "p-4")
);

// Refinements are permitted
assert_eq!(
   "p-4 py-2",
   tw_merge!("p-4", "py-2")
);

You can use Options to exclude certain classes from being merged

use rustui_merge::*;

assert_eq!(
  "flex justify-center",
  tw_join!("flex", (false).then_some("items-center"), (true).then_some("justify-center"))
)

Custom Tailwind Prefix/Separator

Use [merge::set_merge_options] to set global options for [tw_merge!] and variant macros.

This can only be set once. Subsequent calls will be ignored.

use rustui_merge::{*, merge::*};

const OPTIONS: MergeOptions = MergeOptions {
    prefix: "tw-",
    separator: ":",
};

// Before setting options, the default (no prefix) is used
assert_eq!(
  "tw-bg-black tw-bg-white",
  tw_merge!("tw-bg-black", "tw-bg-white"),
);

set_merge_options(OPTIONS);

assert_eq!(
  "tw-bg-white",
  tw_merge!("tw-bg-black", "tw-bg-white"),
);

Usage: Variants

Useful for building components with first class support for tailwind. By default, conflicts are merged using [tw_merge()].

Each [TwClass] represents a UI element with customizable properties (property is a "variant"). Each variant is represented by a [TwVariant], which must be an enum with a default case.

The classes are merged in the following order, with the last class takes precedence:

1. Base class from [TwClass]
2. Base class from [TwVariant]
3. Enum variant class from [TwVariant]
4. Override class using [IntoTailwindClass::with_class] on the struct or builder

use rustui_merge::*;

// Your Component Type
#[derive(TwClass)]
// Optional base class
#[tw(class = "flex")]
struct Btn {
    size: BtnSize,
    color: BtnColor,
}

// Variant for size
#[derive(TwVariant)]
enum BtnSize {
    #[tw(default, class = "h-9 px-4 py-2")]
    Default,
    #[tw(class = "h-8 px-3")]
    Sm,
    #[tw(class = "h-10 px-8")]
    Lg,
}

// Variant for color
#[derive(TwVariant)]
enum BtnColor {
    #[tw(default, class = "bg-blue-500 text-blue-100")]
    Blue,
    #[tw(class = "bg-red-500 text-red-100")]
    Red,
}

You can now use the Btn struct to generate Tailwind classes, using builder syntax, or using the struct directly

Struct Syntax

let button = Btn {
    size: BtnSize::Default,
    color: BtnColor::Blue,
};

assert_eq!(
   "flex h-9 px-4 py-2 bg-blue-500 text-blue-100",
   button.to_class()
);

// Conflicts are resolved (bg-blue-500 is knocked out in favor of override)
assert_eq!(
   "flex h-9 px-4 py-2 text-blue-100 bg-green-500",
   button.with_class("bg-green-500")
);

Builder Syntax

You access the builder using the variants method. Every variant that is not provided will be replaced with the default variant.

assert_eq!(
   "flex h-8 px-3 bg-red-500 text-red-100",
   Btn::builder()
      .size(BtnSize::Sm)
      .color(BtnColor::Red)
      .to_class()
);

assert_eq!(
   "flex h-8 px-3 text-red-100 bg-green-500",
   Btn::builder()
      .size(BtnSize::Sm)
      .color(BtnColor::Red)
      .with_class("bg-green-500")
);

VSCode Intellisense

You can enable autocompletion inside #[tw()] using the steps below:

1. Install the "Tailwind CSS IntelliSense" Visual Studio Code extension

2. Add the following to your settings.json:

{
  "tailwindCSS.experimental.classRegex": [
    ["#[tw\\\\([^\\]]*class\\s*=\\s*\"([^\"]*)\"\\)]", "\"([^\"]*)\""]
  ]
}