Vue

Installation

npm

npm install -D @ecss/vite-plugin @ecss/typescript-plugin

pnpm

pnpm add -D @ecss/vite-plugin @ecss/typescript-plugin

yarn

yarn add -D @ecss/vite-plugin @ecss/typescript-plugin

Vite Configuration

// vite.config.ts
import { defineConfig } from 'vite';
import vue from '@vitejs/plugin-vue';
import ecss from '@ecss/vite-plugin';

export default defineConfig({
  plugins: [
    ecss(), // ← must come before vue()
    vue(),
  ],
});

TypeScript

// tsconfig.app.json
{
  "compilerOptions": {
    "plugins": [{ "name": "@ecss/typescript-plugin" }]
  }
}

classAttribute

Vue uses the class attribute (not className like React). Add an ecss.config.json file to the root of your project:

// ecss.config.json
{
  "classAttribute": "class"
}

Now the style factory returns class instead of className:

styles.Button({ variant: 'primary' });
// → { class: 'Button-a3f2c1', 'data-e-a3f2c1-variant': 'primary' }

Binding attributes with v-bind

In Vue it's convenient to use v-bind with an object — it applies all keys as attributes:

<button v-bind="styles.Button({ variant, size })">
  <slot />
</button>

Example: Button component

Button.ecss

@state-variant Variant {
  values: primary, danger, ghost;
}

@state-variant Size {
  values: sm, md, lg;
}

@state-def Button(--variant Variant: primary, --size Size: md, --disabled boolean) {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  border: none;
  border-radius: 6px;
  font-weight: 600;
  cursor: pointer;
  transition: opacity 0.15s;

  &:hover {
    opacity: 0.85;
  }

  @if (--disabled) {
    opacity: 0.4;
    cursor: not-allowed;
    pointer-events: none;
  }

  @if (--size == sm) {
    padding: 4px 8px;
    font-size: 12px;
  }
  @elseif (--size == md) {
    padding: 8px 16px;
    font-size: 14px;
  }
  @else {
    padding: 12px 24px;
    font-size: 16px;
  }

  @if (--variant == primary) {
    background: #646cff;
    color: #fff;
  }
  @elseif (--variant == danger) {
    background: #e53e3e;
    color: #fff;
  }
  @else {
    background: transparent;
    border: 1px solid currentColor;
    color: inherit;
  }
}

Button.vue

<script setup lang="ts">
import styles from './Button.ecss';

interface Props {
  variant?: 'primary' | 'danger' | 'ghost';
  size?: 'sm' | 'md' | 'lg';
  disabled?: boolean;
}

const { variant = 'primary', size = 'md', disabled } = defineProps<Props>();
</script>

<template>
  <button v-bind="styles.Button({ variant, size, disabled })">
    <slot />
  </button>
</template>

App.vue

<script setup lang="ts">
import Button from './components/Button.vue';
</script>

<template>
  <div>
    <Button variant="primary">Save</Button>
    <Button variant="danger" size="sm">Delete</Button>
    <Button variant="ghost" :disabled="true">Unavailable</Button>
  </div>
</template>

Combining classes

Vue automatically merges class from v-bind with other class bindings on the same element:

<template>
  <!-- Vue merges class from ECSS and class="my-button" automatically -->
  <button v-bind="styles.Button({ variant })" class="my-button">
    <slot />
  </button>
</template>

TIP

This is a Vue feature — you don't need to manually merge classes. class directives and v-bind objects containing class are automatically merged.