Wine Nutrition QR Code Generator

A WordPress plugin for managing wine product nutrition information with automatically generated QR codes — built for EU wine labelling compliance.

Overview

This plugin adds a custom post type for wine nutrition data. Each entry stores wine-specific nutritional values and automatically generates a downloadable SVG QR code that links to the product's nutrition page. Designed for use by wineries, wine retailers, and importers who need to comply with EU regulation (EU 2021/2117) requiring nutrition labelling on wine bottles.

Features

• Custom post type (naehrwerte) for wine nutrition entries
• Automatic QR code generation (SVG) linking to each product's page
• Smart regeneration — QR codes are only regenerated when the post URL changes
• Admin preview & download — view and download the QR code directly from the post editor
• Nutritional calculations — automatically calculates energy (kJ/kcal) and carbohydrate values from raw wine data using EU-standard formulas
• Frontend shortcode for embedding nutrition info on any page or post
• Responsive layout — two-column on desktop, single-column on mobile
• German localization — all admin labels and field names in German

Requirements

Note: This plugin requires ACF Pro. A warning will be shown in the admin if it is not active.

Installation

1. Clone or download this repository into your wp-content/plugins/ directory:

   cd wp-content/plugins/
   git clone <repository-url> wine_nutrition-qr-code-generator

2. Install PHP dependencies via Composer:

   cd wine_nutrition-qr-code-generator
   composer install --no-dev

3. Activate the plugin in the WordPress admin under Plugins.

4. Make sure Advanced Custom Fields Pro is installed and active.

Usage

Creating a Nutrition Entry

1. Go to Nährwerte in the WordPress admin menu.
2. Click Add New.
3. Fill in the wine details:
   • Product image
   • Description
   • Volume (default: 750 ml)
   • Alcohol content (%vol)
   • Residual sugar (g/l)
   • Total acidity (g/l)
   • Glycerin (g/l)
   • Ingredients
4. Publish the post. A QR code SVG is generated automatically.

Downloading the QR Code

After publishing, scroll down to the QR-Code Vorschau & Download meta box in the post editor. Click the download button to save the SVG file for use on wine labels.

Displaying Nutrition Info on the Frontend

Use the shortcode on any page or post:

[wine_nutrition_fields]

For legacy installations, the alias [naehrwerte_felder] is also supported.

To display a specific wine product, create a page using the permalink of a naehrwerte post — the template will render automatically for singular posts of that type.

Nutritional Calculation

Energy values and carbohydrates are calculated per 100 ml using EU-standard formulas:

Energy:

kJ  = alcohol×29 + sugar×17 + acidity×13 + glycerin×10
kcal = alcohol×6.96 + sugar×4.08 + acidity×3.12 + glycerin×2.4

Carbohydrates:

Carbohydrates = residual sugar (g/100ml) + glycerin (g/100ml)

File Structure

wine_nutrition-qr-code-generator/
├── functions.php                            # Plugin entry point
├── composer.json                            # PHP dependencies
├── includes/
│   ├── class-wine-nutrition.php            # Bootstrap / initialization
│   ├── class-wine-nutrition-cpt.php        # Custom post type registration
│   ├── class-wine-nutrition-qr.php         # QR code generation
│   └── class-wine-nutrition-shortcode.php  # Frontend shortcode
├── assets/
│   ├── css/style.css                        # Frontend styles
│   └── images/wine-glass-icon.png
└── vendor/                                  # Composer dependencies

QR Code Storage

Generated QR codes are stored in:

wp-content/uploads/wine-nutrition-qrcodes/qr_[post-id]_[post-slug].svg

The URL to each file is stored in the post meta key _qr_code_url.

Uninstall

When the plugin is deleted through the WordPress admin, the wine-nutrition-qrcodes/ upload directory and all generated SVG files are automatically removed.

License

Proprietary — © more than ads. All rights reserved.