Installation

Method 1: WordPress Admin Upload

1. Download the plugin zip file
2. Go to Plugins > Add New in your WordPress admin
3. Click Upload Plugin
4. Choose the zip file and click Install Now
5. Click Activate Plugin

Method 2: Manual Installation

1. Extract the plugin files to /wp-content/plugins/wc-price-history-compliance/
2. Go to Plugins in WordPress admin
3. Find "WooCommerce Price History & Sale Compliance" and click Activate

Configuration

Navigate to WooCommerce > Settings > Price History to configure the plugin.

Compliance Settings

Enable 30-Day Lowest Price Message

Message Text

Custom Period (Days)

Law/Compliance Tooltip

Price Chart Settings

Enable Price History Chart

Features

Automated Price Tracking

The plugin automatically records price changes when:

• Product regular price is updated
• Product sale price is set or modified
• Bulk price updates are performed
• Scheduled sales begin or end

Compliance Message Display

When Displayed:

• Only appears during active sales (when sale price < regular price)
• Shows the lowest price recorded in the specified period
• Updates automatically when prices change

Price History Charts

Admin Reports

Access via WooCommerce > Price History:

• Complete price change log
• Product search functionality
• Pagination for large datasets
• Export capabilities for compliance audits

Technical Details

Database Schema

The plugin creates a custom table wp_wc_price_history:

CREATE TABLE wp_wc_price_history (
    id mediumint(9) NOT NULL AUTO_INCREMENT,
    product_id bigint(20) NOT NULL,
    price decimal(19,4) NOT NULL,
    date datetime DEFAULT '0000-00-00 00:00:00' NOT NULL,
    PRIMARY KEY (id),
    KEY product_id (product_id)
);

File Structure

/wc-price-history-compliance/
├── wc-price-history-compliance.php    (Main plugin file)
├── includes/
│   ├── class-price-tracker.php        (Price tracking logic)
│   ├── class-display-handler.php      (Frontend display)
│   ├── class-admin-reports.php        (Admin interface)
│   ├── class-admin-settings.php       (Settings page)
│   └── class-install-handler.php      (Activation/deactivation)
├── assets/
│   ├── js/
│   │   ├── chart.js                   (Frontend chart functionality)
│   │   └── admin.js                   (Admin interface scripts)
│   └── css/
│       ├── frontend.css               (Frontend styling)
│       └── admin.css                  (Admin styling)
├── languages/                         (Translation files)
└── readme.txt                        (WordPress readme)

WooCommerce Compatibility

• HPOS Compatible: Declares compatibility with High Performance Order Storage
• WooCommerce Blocks: Works with classic and block-based themes
• Multisite: Supports WordPress multisite installations
• Caching: Compatible with popular caching plugins

Performance Considerations

Troubleshooting

Common Issues

Compliance Message Not Showing

1. Verify the product is actually on sale (sale price < regular price)
2. Check that "Enable 30-Day Lowest Price Message" is enabled in settings
3. Ensure there's price history data (product must have been updated since plugin activation)

Price Charts Not Displaying

1. Confirm "Enable Price History Chart" is enabled
2. Check browser console for JavaScript errors
3. Verify Chart.js is loading (check network tab in browser dev tools)
4. Ensure the product has at least 2 price history entries

Variable Products Not Working

1. Clear any page caching
2. Check that variations have separate price history entries
3. Verify AJAX requests are succeeding (check browser network tab)

Missing Price History Data

Debug Mode

Add this to wp-config.php for detailed logging:

define('WCPC_DEBUG', true);

Developer Guide

Hooks and Filters

Filters

wcpc_lowest_price_message_text

Customize the compliance message display:

add_filter('wcpc_lowest_price_message_text', function($message, $product, $lowest_price) {
    return '<div class="custom-compliance">' . $message . '</div>';
}, 10, 3);

wcpc_price_history_chart_data

Modify chart data before display:

add_filter('wcpc_price_history_chart_data', function($data, $product_id) {
    // Customize chart data
    return $data;
}, 10, 2);

wcpc_compliance_period_days

Dynamically adjust the compliance period:

add_filter('wcpc_compliance_period_days', function($days, $product) {
    // Return different periods based on product category
    return $days;
}, 10, 2);

Actions

wcpc_price_recorded

Triggered when a new price is recorded:

add_action('wcpc_price_recorded', function($product_id, $price, $date) {
    // Custom logic when price is recorded
}, 10, 3);

Custom Styling

Override default styles by targeting these CSS classes:

/* Compliance message */
.wcpc-lowest-price-message {
    /* Your custom styles */
}

/* Chart container */
.wcpc-chart-container {
    /* Your custom styles */
}

/* Law tooltip */
.wcpc-law-tooltip {
    /* Your custom styles */
}

Database Access

Access price history data programmatically:

global $wpdb;
$table_name = $wpdb->prefix . 'wc_price_history';

$price_history = $wpdb->get_results($wpdb->prepare(
    "SELECT * FROM $table_name WHERE product_id = %d ORDER BY date DESC",
    $product_id
));

Legal Compliance

EU Omnibus Directive

This plugin is designed to help comply with the EU Omnibus Directive (2019/2161), specifically Article 6a which requires displaying the lowest price in the 30 days prior to a price reduction.

Key Requirements Met

• Automatic tracking of all price changes
• Display of lowest price during sales
• 30-day minimum tracking period (configurable)
• Accurate calculation including sale prices

Multi-Country Considerations