Implement comprehensive stock management integration (v1.1.0)

Added complete inventory tracking system for composable products:
- Stock validation during product selection and add-to-cart
- Automatic stock deduction on order completion/processing
- Automatic stock restoration on order cancellation/refund
- Stock status indicators with visual feedback (In stock, Low stock, Out of stock)
- Prevention of out-of-stock item selection
- Low stock warnings when 5 or fewer items remain
- Order notes documenting all stock changes

New files:
- includes/Stock_Manager.php: Core stock management logic

Modified files:
- includes/Cart_Handler.php: Integrated stock validation
- includes/Product_Selector.php: Added stock info to product data
- includes/Plugin.php: Added Stock_Manager to includes
- templates/product-selector.twig: Stock status display
- assets/css/frontend.css: Stock indicator styling
- languages/*.pot/*.po: 8 new translatable strings

Version bumped to 1.1.0 with updated CHANGELOG.

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude Sonnet 4.5 <noreply@anthropic.com>

CHANGELOG.md

@@ -5,6 +5,35 @@ All notable changes to this project will be documented in this file.
 The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/),
 and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
 
+## [1.1.0] - 2024-12-31
+
+### Added
+
+- **Stock Management Integration**: Complete inventory tracking system for composable products
+  - Stock validation during product selection and add-to-cart
+  - Automatic stock deduction when orders are completed/processed
+  - Automatic stock restoration on order cancellation/refund
+  - Stock status indicators in product selector (In stock, Low stock, Out of stock)
+  - Visual feedback for out-of-stock items (disabled checkboxes, reduced opacity)
+  - Low stock warnings when 5 or fewer items remain
+  - Prevention of out-of-stock item selection
+  - Order notes documenting stock changes
+
+### Technical
+
+- New `Stock_Manager` class handling all stock operations
+- Integration with WooCommerce order status hooks
+- Stock information passed to frontend via Twig template
+- Enhanced CSS styling for stock status badges
+- Stock data stored in order item meta for accurate tracking
+- Backorder support detection and handling
+
+### Translation
+
+- Added 8 new translatable strings for stock messages
+- Updated Italian (Switzerland) translation with stock-related terms
+- Updated translation template (.pot file)
+
 ## [1.0.1] - 2024-12-31
 
 ### Fixed

IMPLEMENTATION.md

@@ -12,7 +12,7 @@ This document provides a technical overview of the WooCommerce Composable Produc
 
 ### Plugin Structure
 
-```
+```txt
 wc-composable-product/
 ├── assets/                  # Frontend assets
 │   ├── css/
@@ -42,6 +42,7 @@ wc-composable-product/
 ### 1. Main Plugin Class (`Plugin.php`)
 
 **Responsibilities:**
+
 - Singleton pattern implementation
 - Twig template engine initialization
 - Hook registration
@@ -49,6 +50,7 @@ wc-composable-product/
 - Asset enqueuing
 
 **Key Methods:**
+
 - `instance()`: Get singleton instance
 - `init_twig()`: Initialize Twig with WordPress functions
 - `render_template()`: Render Twig templates
@@ -59,6 +61,7 @@ wc-composable-product/
 **Extends:** `WC_Product`
 
 **Key Features:**
+
 - Custom product type: `composable`
 - Selection limit management (per-product or global)
 - Pricing mode (fixed or sum)
@@ -67,6 +70,7 @@ wc-composable-product/
 - Price calculation
 
 **Key Methods:**
+
 - `get_selection_limit()`: Get max selectable items
 - `get_pricing_mode()`: Get pricing calculation mode
 - `get_available_products()`: Query available products
@@ -77,6 +81,7 @@ wc-composable-product/
 **Extends:** `WC_Settings_Page`
 
 **Global Settings:**
+
 - Default selection limit
 - Default pricing mode
 - Display options (images, prices, total)
@@ -86,12 +91,14 @@ wc-composable-product/
 ### 4. Product Data Tab (`Admin/Product_Data.php`)
 
 **Responsibilities:**
+
 - Add "Composable Options" tab to product edit page
 - Render selection criteria fields
 - Save product meta data
 - Dynamic field visibility based on criteria type
 
 **Saved Meta:**
+
 - `_composable_selection_limit`: Item limit
 - `_composable_pricing_mode`: Pricing calculation
 - `_composable_criteria_type`: Selection method
@@ -102,11 +109,13 @@ wc-composable-product/
 ### 5. Product Selector (`Product_Selector.php`)
 
 **Responsibilities:**
+
 - Render frontend product selection interface
 - Prepare data for Twig template
 - Apply display settings
 
 **Template Variables:**
+
 - `products`: Available products array
 - `selection_limit`: Max selections
 - `pricing_mode`: Pricing calculation
@@ -115,12 +124,14 @@ wc-composable-product/
 ### 6. Cart Handler (`Cart_Handler.php`)
 
 **Responsibilities:**
+
 - Validate product selection
 - Add selected products to cart data
 - Calculate dynamic pricing
 - Display selected products in cart
 
 **Hooks:**
+
 - `woocommerce_add_to_cart_validation`: Validate selections
 - `woocommerce_add_cart_item_data`: Store selections
 - `woocommerce_before_calculate_totals`: Update prices
@@ -131,6 +142,7 @@ wc-composable-product/
 ### Product Selector Template (`product-selector.twig`)
 
 **Features:**
+
 - Responsive grid layout
 - Checkbox-based selection
 - Product images and prices
@@ -138,6 +150,7 @@ wc-composable-product/
 - AJAX add-to-cart
 
 **Data Attributes:**
+
 - `data-product-id`: Composable product ID
 - `data-selection-limit`: Max selections
 - `data-pricing-mode`: Pricing mode
@@ -146,6 +159,7 @@ wc-composable-product/
 ### JavaScript (`frontend.js`)
 
 **Functionality:**
+
 - Selection limit enforcement
 - Visual feedback on selection
 - Real-time price updates (sum mode)
@@ -153,6 +167,7 @@ wc-composable-product/
 - Error/success messages
 
 **Key Functions:**
+
 - `handleCheckboxChange()`: Selection logic
 - `updateTotalPrice()`: Calculate total
 - `addToCart()`: AJAX add-to-cart
@@ -161,6 +176,7 @@ wc-composable-product/
 ### CSS Styling
 
 **Approach:**
+
 - Grid-based layout (responsive)
 - Card-style product items
 - Visual selection states
@@ -242,6 +258,7 @@ wc-composable-product/
 Generated template: `languages/wc-composable-product.pot`
 
 **Supported Locales (per CLAUDE.md):**
+
 - en_US (English)
 - de_DE, de_DE_informal (German - Germany)
 - de_CH, de_CH_informal (German - Switzerland)
@@ -273,11 +290,13 @@ Generated template: `languages/wc-composable-product.pot`
 ### Hooks & Filters
 
 **Available Filters:**
+
 - `wc_composable_settings`: Modify settings array
 - `woocommerce_product_class`: Custom product class
 - `product_type_selector`: Product type registration
 
 **Customization Points:**
+
 - Twig templates (override in theme)
 - CSS styling (enqueue custom styles)
 - JavaScript behavior (extend object)
@@ -304,6 +323,7 @@ if ($product->get_type() === 'composable') {
 ## Testing Checklist
 
 ### Admin Testing
+
 - [ ] Product type appears in dropdown
 - [ ] Composable Options tab displays
 - [ ] Selection criteria toggle works
@@ -312,6 +332,7 @@ if ($product->get_type() === 'composable') {
 - [ ] Global defaults apply
 
 ### Frontend Testing
+
 - [ ] Product selector renders
 - [ ] Selection limit enforced
 - [ ] Price calculation accurate (both modes)
@@ -320,6 +341,7 @@ if ($product->get_type() === 'composable') {
 - [ ] Checkout processes correctly
 
 ### Edge Cases
+
 - [ ] Empty criteria (no products)
 - [ ] Out of stock products excluded
 - [ ] Invalid product selections rejected
@@ -349,12 +371,14 @@ Potential features for future versions:
 ## Dependencies
 
 ### Runtime
+
 - PHP 8.3+
 - WordPress 6.0+
 - WooCommerce 8.0+
 - Twig 3.0 (via Composer)
 
 ### Development
+
 - Composer for dependency management
 - WP-CLI for i18n operations (optional)
 
@@ -372,6 +396,7 @@ Potential features for future versions:
 ### Release Package
 
 Must include:
+
 - All PHP files
 - `vendor/` directory
 - Assets (CSS, JS)
@@ -380,6 +405,7 @@ Must include:
 - Documentation
 
 Must exclude:
+
 - `.git/` directory
 - `composer.lock`
 - Development files
@@ -388,12 +414,14 @@ Must exclude:
 ## Support & Maintenance
 
 ### Code Standards
+
 - WordPress Coding Standards
 - WooCommerce best practices
 - PSR-4 autoloading
 - Inline documentation
 
 ### Version Control
+
 - Semantic versioning (MAJOR.MINOR.PATCH)
 - Changelog maintained
 - Annotated git tags

assets/css/frontend.css

@@ -54,6 +54,20 @@
     background: #f0f8ff;
 }
 
+.composable-product-item.out-of-stock {
+    opacity: 0.6;
+    cursor: not-allowed;
+}
+
+.composable-product-item.out-of-stock:hover {
+    border-color: #e0e0e0;
+    box-shadow: none;
+}
+
+.composable-product-item.out-of-stock .product-item-label {
+    cursor: not-allowed;
+}
+
 .product-item-label {
     display: block;
     padding: 1rem;
@@ -94,6 +108,33 @@
     font-size: 0.9rem;
 }
 
+.product-item-stock {
+    margin-top: 0.5rem;
+    font-size: 0.85rem;
+}
+
+.stock-status {
+    display: inline-block;
+    padding: 0.25rem 0.5rem;
+    border-radius: 3px;
+    font-weight: 500;
+}
+
+.stock-status.in-stock {
+    color: #2e7d32;
+    background: #e8f5e9;
+}
+
+.stock-status.low-stock {
+    color: #f57c00;
+    background: #fff3e0;
+}
+
+.stock-status.out-of-stock {
+    color: #c62828;
+    background: #ffebee;
+}
+
 .product-item-checkmark {
     position: absolute;
     top: 0.5rem;

includes/Cart_Handler.php

@@ -15,16 +15,26 @@ defined('ABSPATH') || exit;
  * Handles adding composable products to cart and calculating prices
  */
 class Cart_Handler {
+    /**
+     * Stock manager instance
+     *
+     * @var Stock_Manager
+     */
+    private $stock_manager;
+
     /**
      * Constructor
      */
     public function __construct() {
+        $this->stock_manager = new Stock_Manager();
+
         add_filter('woocommerce_add_to_cart_validation', [$this, 'validate_add_to_cart'], 10, 3);
         add_filter('woocommerce_add_cart_item_data', [$this, 'add_cart_item_data'], 10, 2);
         add_filter('woocommerce_get_cart_item_from_session', [$this, 'get_cart_item_from_session'], 10, 2);
         add_filter('woocommerce_get_item_data', [$this, 'display_cart_item_data'], 10, 2);
         add_action('woocommerce_before_calculate_totals', [$this, 'calculate_cart_item_price']);
         add_action('woocommerce_single_product_summary', [$this, 'render_product_selector'], 25);
+        add_action('woocommerce_checkout_create_order_line_item', [$this->stock_manager, 'store_selected_products_in_order'], 10, 3);
     }
 
     /**
@@ -87,6 +97,13 @@ class Cart_Handler {
             }
         }
 
+        // Validate stock availability
+        $stock_validation = $this->stock_manager->validate_stock_availability($selected_products, $quantity);
+        if ($stock_validation !== true) {
+            wc_add_notice($stock_validation, 'error');
+            return false;
+        }
+
         return $passed;
     }
 

includes/Plugin.php

@@ -93,6 +93,7 @@ class Plugin {
         require_once WC_COMPOSABLE_PRODUCT_PATH . 'includes/Admin/Settings.php';
         require_once WC_COMPOSABLE_PRODUCT_PATH . 'includes/Admin/Product_Data.php';
         require_once WC_COMPOSABLE_PRODUCT_PATH . 'includes/Product_Type.php';
+        require_once WC_COMPOSABLE_PRODUCT_PATH . 'includes/Stock_Manager.php';
         require_once WC_COMPOSABLE_PRODUCT_PATH . 'includes/Cart_Handler.php';
         require_once WC_COMPOSABLE_PRODUCT_PATH . 'includes/Product_Selector.php';
 

includes/Product_Selector.php

@@ -33,9 +33,14 @@ class Product_Selector {
         $show_prices = get_option('wc_composable_show_prices', 'yes') === 'yes';
         $show_total = get_option('wc_composable_show_total', 'yes') === 'yes';
 
+        // Get stock manager for stock information
+        $stock_manager = new Stock_Manager();
+
         // Prepare product data for template
         $products_data = [];
         foreach ($available_products as $available_product) {
+            $stock_info = $stock_manager->get_product_stock_info($available_product->get_id());
+
             $products_data[] = [
                 'id' => $available_product->get_id(),
                 'name' => $available_product->get_name(),
@@ -43,6 +48,11 @@ class Product_Selector {
                 'price_html' => $available_product->get_price_html(),
                 'image_url' => wp_get_attachment_image_url($available_product->get_image_id(), 'thumbnail'),
                 'permalink' => $available_product->get_permalink(),
+                'stock_status' => $stock_info['stock_status'],
+                'in_stock' => $stock_info['in_stock'],
+                'stock_quantity' => $stock_info['stock_quantity'],
+                'managing_stock' => $stock_info['managing_stock'],
+                'backorders_allowed' => $stock_info['backorders_allowed'],
             ];
         }
 

includes/Stock_Manager.php

@@ -0,0 +1,283 @@
+<?php
+/**
+ * Stock Manager
+ *
+ * @package WC_Composable_Product
+ */
+
+namespace WC_Composable_Product;
+
+defined('ABSPATH') || exit;
+
+/**
+ * Stock Manager Class
+ *
+ * Handles stock management for composable products
+ */
+class Stock_Manager {
+	/**
+	 * Constructor
+	 */
+	public function __construct() {
+		// Hook into order completion to reduce stock
+		add_action('woocommerce_order_status_completed', [$this, 'reduce_stock_on_order_complete'], 10, 1);
+		add_action('woocommerce_order_status_processing', [$this, 'reduce_stock_on_order_complete'], 10, 1);
+
+		// Hook into order cancellation/refund to restore stock
+		add_action('woocommerce_order_status_cancelled', [$this, 'restore_stock_on_order_cancel'], 10, 1);
+		add_action('woocommerce_order_status_refunded', [$this, 'restore_stock_on_order_cancel'], 10, 1);
+
+		// Prevent double stock reduction
+		add_filter('woocommerce_can_reduce_order_stock', [$this, 'prevent_composable_stock_reduction'], 10, 2);
+	}
+
+	/**
+	 * Validate stock availability for selected products
+	 *
+	 * @param array $selected_product_ids Array of product IDs
+	 * @param int $quantity Quantity of composable product being added
+	 * @return bool|string True if in stock, error message otherwise
+	 */
+	public function validate_stock_availability($selected_product_ids, $quantity = 1) {
+		foreach ($selected_product_ids as $product_id) {
+			$product = wc_get_product($product_id);
+
+			if (!$product) {
+				continue;
+			}
+
+			// Skip stock check if stock management is disabled for this product
+			if (!$product->managing_stock()) {
+				continue;
+			}
+
+			$stock_quantity = $product->get_stock_quantity();
+
+			// Check if product is in stock
+			if (!$product->is_in_stock()) {
+				return sprintf(
+					/* translators: %s: product name */
+					__('"%s" is out of stock and cannot be selected.', 'wc-composable-product'),
+					$product->get_name()
+				);
+			}
+
+			// Check if enough stock is available
+			if ($stock_quantity !== null && $stock_quantity < $quantity) {
+				return sprintf(
+					/* translators: 1: product name, 2: stock quantity */
+					__('Only %2$d of "%1$s" are available in stock.', 'wc-composable-product'),
+					$product->get_name(),
+					$stock_quantity
+				);
+			}
+
+			// Check for backorders
+			if ($product->backorders_allowed()) {
+				continue;
+			}
+		}
+
+		return true;
+	}
+
+	/**
+	 * Check if a product has sufficient stock
+	 *
+	 * @param int $product_id Product ID
+	 * @param int $required_quantity Required quantity
+	 * @return array Stock information [in_stock, stock_quantity, backorders_allowed]
+	 */
+	public function get_product_stock_info($product_id, $required_quantity = 1) {
+		$product = wc_get_product($product_id);
+
+		if (!$product) {
+			return [
+				'in_stock' => false,
+				'stock_quantity' => 0,
+				'backorders_allowed' => false,
+				'stock_status' => 'outofstock',
+			];
+		}
+
+		$stock_quantity = $product->get_stock_quantity();
+		$managing_stock = $product->managing_stock();
+
+		return [
+			'in_stock' => $product->is_in_stock(),
+			'stock_quantity' => $stock_quantity,
+			'backorders_allowed' => $product->backorders_allowed(),
+			'stock_status' => $product->get_stock_status(),
+			'managing_stock' => $managing_stock,
+			'has_enough_stock' => !$managing_stock || $stock_quantity === null || $stock_quantity >= $required_quantity,
+		];
+	}
+
+	/**
+	 * Reduce stock for composable products when order is completed
+	 *
+	 * @param int $order_id Order ID
+	 */
+	public function reduce_stock_on_order_complete($order_id) {
+		$order = wc_get_order($order_id);
+
+		if (!$order) {
+			return;
+		}
+
+		// Check if stock has already been reduced
+		if ($order->get_meta('_composable_stock_reduced', true)) {
+			return;
+		}
+
+		foreach ($order->get_items() as $item) {
+			$product = $item->get_product();
+
+			if (!$product || $product->get_type() !== 'composable') {
+				continue;
+			}
+
+			// Get selected products from order item meta
+			$selected_products = $item->get_meta('_composable_products', true);
+
+			if (empty($selected_products) || !is_array($selected_products)) {
+				continue;
+			}
+
+			$quantity = $item->get_quantity();
+
+			// Reduce stock for each selected product
+			foreach ($selected_products as $product_id) {
+				$selected_product = wc_get_product($product_id);
+
+				if (!$selected_product || !$selected_product->managing_stock()) {
+					continue;
+				}
+
+				$stock_quantity = $selected_product->get_stock_quantity();
+
+				if ($stock_quantity !== null) {
+					$new_stock = $stock_quantity - $quantity;
+					$selected_product->set_stock_quantity($new_stock);
+					$selected_product->save();
+
+					// Add order note
+					$order->add_order_note(
+						sprintf(
+							/* translators: 1: product name, 2: quantity, 3: remaining stock */
+							__('Stock reduced for "%1$s": -%2$d (remaining: %3$d)', 'wc-composable-product'),
+							$selected_product->get_name(),
+							$quantity,
+							$new_stock
+						)
+					);
+				}
+			}
+		}
+
+		// Mark stock as reduced
+		$order->update_meta_data('_composable_stock_reduced', true);
+		$order->save();
+	}
+
+	/**
+	 * Restore stock when order is cancelled or refunded
+	 *
+	 * @param int $order_id Order ID
+	 */
+	public function restore_stock_on_order_cancel($order_id) {
+		$order = wc_get_order($order_id);
+
+		if (!$order) {
+			return;
+		}
+
+		// Check if stock was reduced
+		if (!$order->get_meta('_composable_stock_reduced', true)) {
+			return;
+		}
+
+		foreach ($order->get_items() as $item) {
+			$product = $item->get_product();
+
+			if (!$product || $product->get_type() !== 'composable') {
+				continue;
+			}
+
+			// Get selected products from order item meta
+			$selected_products = $item->get_meta('_composable_products', true);
+
+			if (empty($selected_products) || !is_array($selected_products)) {
+				continue;
+			}
+
+			$quantity = $item->get_quantity();
+
+			// Restore stock for each selected product
+			foreach ($selected_products as $product_id) {
+				$selected_product = wc_get_product($product_id);
+
+				if (!$selected_product || !$selected_product->managing_stock()) {
+					continue;
+				}
+
+				$stock_quantity = $selected_product->get_stock_quantity();
+
+				if ($stock_quantity !== null) {
+					$new_stock = $stock_quantity + $quantity;
+					$selected_product->set_stock_quantity($new_stock);
+					$selected_product->save();
+
+					// Add order note
+					$order->add_order_note(
+						sprintf(
+							/* translators: 1: product name, 2: quantity, 3: new stock */
+							__('Stock restored for "%1$s": +%2$d (total: %3$d)', 'wc-composable-product'),
+							$selected_product->get_name(),
+							$quantity,
+							$new_stock
+						)
+					);
+				}
+			}
+		}
+
+		// Mark stock as restored
+		$order->update_meta_data('_composable_stock_reduced', false);
+		$order->save();
+	}
+
+	/**
+	 * Prevent WooCommerce from reducing stock for composable products
+	 * We handle stock reduction manually for selected products
+	 *
+	 * @param bool $reduce_stock Whether to reduce stock
+	 * @param \WC_Order $order Order object
+	 * @return bool
+	 */
+	public function prevent_composable_stock_reduction($reduce_stock, $order) {
+		foreach ($order->get_items() as $item) {
+			$product = $item->get_product();
+
+			if ($product && $product->get_type() === 'composable') {
+				// We'll handle stock reduction manually
+				return false;
+			}
+		}
+
+		return $reduce_stock;
+	}
+
+	/**
+	 * Store selected products in order item meta
+	 *
+	 * @param \WC_Order_Item_Product $item Order item
+	 * @param string $cart_item_key Cart item key
+	 * @param array $values Cart item values
+	 */
+	public function store_selected_products_in_order($item, $cart_item_key, $values) {
+		if (isset($values['composable_products']) && !empty($values['composable_products'])) {
+			$item->add_meta_data('_composable_products', $values['composable_products'], true);
+		}
+	}
+}

languages/wc-composable-product-it_CH.po

@@ -198,3 +198,35 @@ msgstr "Inserire i codici articolo dei prodotti separati da virgole."
 #: includes/Admin/Product_Data.php
 msgid "SKU-1, SKU-2, SKU-3"
 msgstr "COD-1, COD-2, COD-3"
+
+#: includes/Stock_Manager.php
+msgid "\"%s\" is out of stock and cannot be selected."
+msgstr "\"%s\" è esaurito e non può essere selezionato."
+
+#: includes/Stock_Manager.php
+msgid "Only %2$d of \"%1$s\" are available in stock."
+msgstr "Solo %2$d di \"%1$s\" sono disponibili in magazzino."
+
+#: includes/Stock_Manager.php
+msgid "Stock reduced for \"%1$s\": -%2$d (remaining: %3$d)"
+msgstr "Giacenza ridotta per \"%1$s\": -%2$d (rimanenti: %3$d)"
+
+#: includes/Stock_Manager.php
+msgid "Stock restored for \"%1$s\": +%2$d (total: %3$d)"
+msgstr "Giacenza ripristinata per \"%1$s\": +%2$d (totale: %3$d)"
+
+#: templates/product-selector.twig
+msgid "Out of stock"
+msgstr "Esaurito"
+
+#: templates/product-selector.twig
+msgid "Only"
+msgstr "Solo"
+
+#: templates/product-selector.twig
+msgid "left"
+msgstr "rimasti"
+
+#: templates/product-selector.twig
+msgid "In stock"
+msgstr "Disponibile"

languages/wc-composable-product.pot

@@ -197,3 +197,35 @@ msgstr ""
 #: includes/Admin/Product_Data.php
 msgid "SKU-1, SKU-2, SKU-3"
 msgstr ""
+
+#: includes/Stock_Manager.php
+msgid "\"%s\" is out of stock and cannot be selected."
+msgstr ""
+
+#: includes/Stock_Manager.php
+msgid "Only %2$d of \"%1$s\" are available in stock."
+msgstr ""
+
+#: includes/Stock_Manager.php
+msgid "Stock reduced for \"%1$s\": -%2$d (remaining: %3$d)"
+msgstr ""
+
+#: includes/Stock_Manager.php
+msgid "Stock restored for \"%1$s\": +%2$d (total: %3$d)"
+msgstr ""
+
+#: templates/product-selector.twig
+msgid "Out of stock"
+msgstr ""
+
+#: templates/product-selector.twig
+msgid "Only"
+msgstr ""
+
+#: templates/product-selector.twig
+msgid "left"
+msgstr ""
+
+#: templates/product-selector.twig
+msgid "In stock"
+msgstr ""

templates/product-selector.twig

@@ -10,7 +10,7 @@
 
     <div class="composable-products-grid">
         {% for product in products %}
-        <div class="composable-product-item" data-product-id="{{ product.id }}" data-price="{{ product.price }}">
+        <div class="composable-product-item{% if not product.in_stock %} out-of-stock{% endif %}" data-product-id="{{ product.id }}" data-price="{{ product.price }}" data-stock-status="{{ product.stock_status }}">
             <div class="product-item-inner">
                 <label class="product-item-label">
                     <input type="checkbox"
@@ -18,7 +18,8 @@
                            value="{{ product.id }}"
                            class="composable-product-checkbox"
                            data-product-id="{{ product.id }}"
-                           data-price="{{ product.price }}">
+                           data-price="{{ product.price }}"
+                           {% if not product.in_stock %}disabled{% endif %}>
 
                     {% if show_images and product.image_url %}
                     <div class="product-item-image">
@@ -34,6 +35,16 @@
                             {{ product.price_html|raw }}
                         </div>
                         {% endif %}
+
+                        <div class="product-item-stock">
+                            {% if not product.in_stock %}
+                                <span class="stock-status out-of-stock">{{ __('Out of stock') }}</span>
+                            {% elseif product.managing_stock and product.stock_quantity is not null and product.stock_quantity <= 5 %}
+                                <span class="stock-status low-stock">{{ __('Only') }} {{ product.stock_quantity }} {{ __('left') }}</span>
+                            {% elseif product.in_stock %}
+                                <span class="stock-status in-stock">{{ __('In stock') }}</span>
+                            {% endif %}
+                        </div>
                     </div>
 
                     <span class="product-item-checkmark"></span>

wc-composable-product.php

@@ -3,7 +3,7 @@
  * Plugin Name: WooCommerce Composable Products
  * Plugin URI: https://github.com/magdev/wc-composable-product
  * Description: Create composable products where customers select a limited number of items from a configurable set
- * Version: 1.0.1
+ * Version: 1.1.0
  * Author: Marco Graetsch
  * Author URI: https://example.com
  * License: GPL v3 or later
@@ -19,7 +19,7 @@
 defined('ABSPATH') || exit;
 
 // Define plugin constants
-define('WC_COMPOSABLE_PRODUCT_VERSION', '1.0.1');
+define('WC_COMPOSABLE_PRODUCT_VERSION', '1.1.0');
 define('WC_COMPOSABLE_PRODUCT_FILE', __FILE__);
 define('WC_COMPOSABLE_PRODUCT_PATH', plugin_dir_path(__FILE__));
 define('WC_COMPOSABLE_PRODUCT_URL', plugin_dir_url(__FILE__));