frontend-development

---

name: frontend-development description: Provides frontend development guidelines for Nette. Use when working with Vite, SCSS, JavaScript, Nette Assets, or build configuration.

Frontend Development

Frontend built with modern tooling and seamlessly integrated with Nette backend through Nette Assets.

For complete Nette Assets reference, see assets.md. For Vite integration details, see vite.md.

Technology Stack

• Build system: Vite with TypeScript support
• JavaScript: ES Modules (ESM) with "type": "module" in package.json
• Styling: SCSS with modular component architecture
• Asset integration: Nette Assets for PHP-frontend bridge
• Admin framework: Bootstrap for rapid interface development
• Code quality: ESLint with @nette/eslint-plugin
• Forms: Nette Forms with progressive enhancement

Asset Architecture Strategy

Source vs Built Assets separation:

• Development assets: assets/ directory with source files (SCSS, TypeScript, images)
• Production assets: www/assets/ with optimized, versioned files for browsers

Coding Standards

• Use single quotes for strings unless containing apostrophes (CSS, SCSS, JavaScript)

Entry Point Decision Matrix

Use separate entry points when:

• Different user contexts with distinct dependencies (frontend vs admin)
• Bundle size optimization is critical

Example strategy:

Copy// assets/front.js - Public website (custom design)
import './css/front.scss';
import './js/components/product-gallery.js';

// assets/admin.js - Administration (Bootstrap-based)
import 'bootstrap/dist/css/bootstrap.css';
import './css/admin.scss';

Organization Patterns

File-per-component approach:

Copyassets/js/
├── components/
│   ├── product-form.js     ← Reusable form component
│   ├── image-gallery.js    ← Product image viewer
├── pages/
│   ├── blog.css            ← Page-specific enhancements
│   └── checkout.css        ← Multi-step checkout flow
└── utils/
	├── ajax.js            ← AJAX utilities
	└── validation.js      ← Form validation helpers

Nette Assets Integration Patterns

Basic asset loading

Copy{* Loads complete bundle with all dependencies *}
{asset 'front.js'}

Configuration

Copyassets:
	mapping:
		default:
			type: vite
			devServer: true    # Enable HMR in debug mode

Data Flow from Backend to Frontend

Passing data to JavaScript:

Copy{* In template *}
<script>
window.appConfig = {
	apiUrl: {$baseUrl . '/api'},
	userId: {$user->isLoggedIn() ? $user->getId() : 'null'},
	locale: {$locale},
	csrfToken: {$csrfToken}
};
</script>
{asset 'front.js'}

Copy// In JavaScript component
const { apiUrl, userId, csrfToken } = window.appConfig;

fetch(`${apiUrl}/user-data`, {
	headers: { 'X-CSRF-Token': csrfToken }
});

Nette Forms Integration

Requires nette-forms npm package:

Copynpm install nette-forms

Standard enhancement pattern:

Copyimport netteForms from 'nette-forms';

// Initialize Nette Forms validation
netteForms.initOnLoad();

ESLint Configuration

Copynpm install --save-dev @nette/eslint-plugin eslint

Basic configuration with recommended rules:

Copy// eslint.config.js
import nette from '@nette/eslint-plugin';
import { defineConfig } from 'eslint/config';

export default defineConfig([
	{
		extends: [nette.configs.recommended],
	},
]);

Linting JavaScript in Latte templates:

Copynpm install --save-dev eslint-plugin-html

Copy// eslint.config.js
import nette from '@nette/eslint-plugin';
import pluginHtml from 'eslint-plugin-html';
import { defineConfig } from 'eslint/config';

export default defineConfig([
	{
		extends: [nette.configs.recommended],
	},
	{
		files: ['app/**/*.latte'],
		plugins: {
			html: pluginHtml,
		},
		processor: '@nette/latte',  // Handles Latte tags in JS
	},
]);

This allows ESLint to check JavaScript inside <script> tags with Latte variables:

Copy<script>
let name = {$name};
</script>

TypeScript support:

Copynpm install --save-dev typescript typescript-eslint

Copyimport nette from '@nette/eslint-plugin/typescript';

export default defineConfig([
	{
		extends: [nette.configs.typescript],
	},
]);

Custom rules:

• @nette/no-this-in-arrow-except - Prevents this binding issues in arrow functions
• @nette/prefer-line-comments - Enforces // over /* */ for single-line comments

Tailwind CSS Integration

When using Tailwind CSS, configure it to scan Latte templates for class names:

Copy/* assets/css/app.css */
@import 'tailwindcss';
@source '../app/**/*.latte';

Essential Commands

Copy# Start the development server with HMR
npm run dev

# Build assets for production
npm run build

# Build assets for development
npm run build:dev

# Run ESLint checks
npm run lint

# Run ESLint and fix issues
npm run lint:fix

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Online Documentation

For detailed information:

• Nette Assets - asset management
• Vite Integration - Vite setup