Replace sidebar menu with collapsible category tree showing items

config.php

@@ -45,3 +45,32 @@ $twig->addGlobal('app_name', APP_NAME);
 // Add translated confirm messages for JS
 $twig->addGlobal('delete_part_confirm', $translator->trans('Are you sure you want to delete this part?'));
 $twig->addGlobal('delete_category_confirm', $translator->trans('Are you sure you want to delete this category?'));
+
+// Build category tree for sidebar
+$db = App\Database\Database::getInstance();
+$categories = App\Models\Category::getAll($db);
+$items = App\Models\Item::getAll($db);
+
+function buildTree($categories, $items, $parentId = null) {
+    $tree = [];
+    foreach ($categories as $cat) {
+        if ($cat['parent_id'] == $parentId) {
+            $node = [
+                'id' => $cat['id'],
+                'name' => $cat['name'],
+                'children' => buildTree($categories, $items, $cat['id']),
+                'items' => []
+            ];
+            foreach ($items as $item) {
+                if ($item['category_id'] == $cat['id']) {
+                    $node['items'][] = $item;
+                }
+            }
+            $tree[] = $node;
+        }
+    }
+    return $tree;
+}
+
+$categoryTree = buildTree($categories, $items);
+$twig->addGlobal('category_tree', $categoryTree);

public/js/app.js

@@ -2,6 +2,22 @@ document.addEventListener('DOMContentLoaded', function() {
     const mainContent = document.getElementById('main-content');
     const appName = document.querySelector('.navbar-brand').textContent;
 
+    // Global function for editing item from tree
+    window.editItem = function(id) {
+        // Create a mock button to reuse handleEditItem
+        const mockBtn = { getAttribute: (attr) => attr === 'data-id' ? id : null };
+        handleEditItem.call(mockBtn);
+    };
+
+    // Function to toggle category children
+    window.toggleCategory = function(span) {
+        const li = span.parentElement;
+        const ul = li.querySelector('ul'); // First ul is children
+        if (ul) {
+            ul.style.display = ul.style.display === 'none' ? 'block' : 'none';
+        }
+    };
+
     // --- Helper Functions ---
     function setPageTitle(title) {
         document.title = `${appName} - ${title}`;

public/style.css

@@ -0,0 +1,26 @@
+.category-tree, .category-tree ul {
+    list-style: none;
+    padding-left: 20px;
+}
+
+.category-tree li {
+    margin: 5px 0;
+}
+
+.category {
+    font-weight: bold;
+    cursor: pointer;
+}
+
+.items {
+    padding-left: 10px;
+}
+
+.item-link {
+    color: #007bff;
+    text-decoration: none;
+}
+
+.item-link:hover {
+    text-decoration: underline;
+}

templates/partials/sidebar.twig

@@ -1,13 +1,27 @@
 {% autoescape %}
-<ul class="nav flex-column nav-pills">
-    <li class="nav-item">
-        <a class="nav-link {% if active_page == 'overview' %}active{% endif %}" href="#" data-route="/">{{ trans('Overview') }}</a>
-    </li>
-    <li class="nav-item">
-        <a class="nav-link {% if active_page == 'categories' %}active{% endif %}" href="#" data-route="/categories">{{ trans('Categories') }}</a>
-    </li>
-    <li class="nav-item">
-        <a class="nav-link {% if active_page == 'parts' %}active{% endif %}" href="#" data-route="/parts">{{ trans('Parts') }}</a>
-    </li>
+{% macro render_node(node) %}
+<li>
+    <span class="category" onclick="toggleCategory(this)">{{ node.name }}</span>
+    {% if node.children %}
+        <ul style="display: none;">
+        {% for child in node.children %}
+            {{ _self.render_node(child) }}
+        {% endfor %}
+        </ul>
+    {% endif %}
+    {% if node.items %}
+        <ul class="items">
+        {% for item in node.items %}
+            <li><a href="#" onclick="editItem({{ item.id }})" class="item-link">{{ item.name }}</a></li>
+        {% endfor %}
+        </ul>
+    {% endif %}
+</li>
+{% endmacro %}
+
+<ul class="category-tree">
+{% for node in category_tree %}
+    {{ _self.render_node(node) }}
+{% endfor %}
 </ul>
 {% endautoescape %}