Release version 1.1.19 - Enhanced duplicate detection

Fixed persistent duplicate settings page by improving duplicate detection
to check by class type and ID instead of strict instance comparison.

Issue:
- Strict instance comparison (===) failed to detect duplicates
- Different object instances of same class not caught by previous check
- Settings page still appearing twice despite singleton and instance caching

Solution:
- Changed duplicate detection from instance comparison to type/ID checks
- Added instanceof WC_TPP_Settings check
- Added get_id() method check for ID 'tier_package_prices'
- Added direct id property check as fallback
- Multiple layers of detection to catch duplicates regardless of how created

Fixes:
- Settings page rendering twice in WooCommerce backend
- Duplicate detection failing for different instances of same class

Changes:
- Enhanced add_settings_page() with multi-layer duplicate detection
- Checks: instanceof, get_id(), and id property
- Returns early if any existing page matches criteria

Technical Details:
- Strict comparison only works if exact same object instance
- Different instances (even of same class/ID) fail === check
- instanceof checks class type regardless of which instance
- ID checks ensure no duplicate pages with same identifier
- Fallback checks handle different WooCommerce versions/implementations

Updated Files:
- includes/class-wc-tpp-admin.php (enhanced duplicate detection)
- wc-tier-and-package-prices.php (version 1.1.19)
- composer.json (version 1.1.19)
- CHANGELOG.md (v1.1.19 section)

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

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

CHANGELOG.md

@@ -5,6 +5,49 @@ All notable changes to WooCommerce Tier and Package Prices will be documented in
 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).
 
+## [1.1.19] - 2025-12-22
+
+### Fixed
+
+- Settings page still appearing twice despite instance caching
+- Duplicate detection using strict instance comparison failing for different object instances
+
+### Changed
+
+- Enhanced duplicate detection to check by class type and ID instead of instance
+- Added `instanceof WC_TPP_Settings` check
+- Added ID-based duplicate detection via `get_id()` method and direct property access
+- Multiple fallback checks to catch duplicates regardless of instance identity
+
+### Technical Details
+
+- Previous strict comparison (`===`) failed when different instances of same class existed
+- New approach checks: instanceof, get_id() method, and id property
+- Returns early if any settings page with ID 'tier_package_prices' found
+- Prevents duplicates even if settings instance recreated or serialized
+
+## [1.1.18] - 2025-12-22
+
+### Fixed
+
+- **ROOT CAUSE IDENTIFIED**: Settings page rendering twice due to automatic instantiation in settings file
+- Settings file being included multiple times via Composer autoloader creating duplicate instances
+
+### Changed
+
+- Removed `return new WC_TPP_Settings();` from bottom of settings file
+- Changed admin class to explicitly instantiate settings with `new WC_TPP_Settings()`
+- Changed from `include` to `require_once` for settings file to prevent multiple loads
+
+### Technical Details
+
+- Settings file (class-wc-tpp-settings.php) was creating instance automatically on include
+- File is in Composer's classmap, so when autoloaded it executed instantiation again
+- Each include/autoload created new instance even with singleton pattern in admin class
+- Solution: Remove automatic instantiation, use `require_once` + explicit `new` in admin class
+- Now settings instance only created once, explicitly, when needed by filter
+- Composer autoload can load class definition without side effects
+
 ## [1.1.17] - 2025-12-22
 
 ### Fixed

composer.json

@@ -1,7 +1,7 @@
 {
     "name": "magdev/wc-tier-package-prices",
     "description": "WooCommerce plugin for tier pricing and package prices with Twig templates",
-    "version": "1.1.17",
+    "version": "1.1.19",
     "type": "wordpress-plugin",
     "license": "GPL-2.0-or-later",
     "authors": [

includes/class-wc-tpp-admin.php

@@ -30,12 +30,26 @@ if (!class_exists('WC_TPP_Admin')) {
      */
     public function add_settings_page($settings) {
         if (null === self::$settings_instance) {
-            self::$settings_instance = include WC_TPP_PLUGIN_DIR . 'includes/class-wc-tpp-settings.php';
+            require_once WC_TPP_PLUGIN_DIR . 'includes/class-wc-tpp-settings.php';
+            self::$settings_instance = new WC_TPP_Settings();
         }
 
         // Check if our settings page is already in the array to prevent duplicates
+        // Check by class type and ID instead of instance comparison
         foreach ($settings as $settings_page) {
-            if ($settings_page === self::$settings_instance) {
+            if ($settings_page instanceof WC_TPP_Settings) {
+                return $settings;
+            }
+            // Also check by ID property if it's a WC_Settings_Page
+            if (is_object($settings_page) &&
+                method_exists($settings_page, 'get_id') &&
+                $settings_page->get_id() === 'tier_package_prices') {
+                return $settings;
+            }
+            // Check id property directly
+            if (is_object($settings_page) &&
+                isset($settings_page->id) &&
+                $settings_page->id === 'tier_package_prices') {
                 return $settings;
             }
         }

includes/class-wc-tpp-settings.php

@@ -141,5 +141,3 @@ if (!class_exists('WC_TPP_Settings')) {
     }
 }
 }
-
-return new WC_TPP_Settings();

wc-tier-and-package-prices.php

@@ -4,7 +4,7 @@
  * Plugin Name: WooCommerce Tier and Package Prices
  * Plugin URI: https://src.bundespruefstelle.ch/magdev/wc-tier-package-prices
  * Description: Add tier pricing and package prices to WooCommerce products with configurable quantities at fixed prices
- * Version: 1.1.17
+ * Version: 1.1.19
  * Author: Marco Graetsch
  * Author URI: https://src.bundespruefstelle.ch/magdev
  * Text Domain: wc-tier-package-prices
@@ -23,7 +23,7 @@ if (!defined('ABSPATH')) {
 
 // Define plugin constants
 if (!defined('WC_TPP_VERSION')) {
-    define('WC_TPP_VERSION', '1.1.17');
+    define('WC_TPP_VERSION', '1.1.19');
 }
 if (!defined('WC_TPP_PLUGIN_DIR')) {
     define('WC_TPP_PLUGIN_DIR', plugin_dir_path(__FILE__));