Add online store cart ( issue #8 )

public/action.php

@@ -0,0 +1,60 @@
+<?php
+
+/*
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/.
+ */
+
+require_once __DIR__ . "/../required.php";
+require_once __DIR__ . "/lib/item.php";
+
+switch ($VARS['action']) {
+    case "addtocart":
+        $item = $VARS['item'];
+        $qty = $VARS['qty'];
+
+        if (!$binstack->has('items', ['AND' => ['itemid' => $item, 'price[>]' => 0]])) {
+            header('Location: ./?page=cart&msg=invaliditem');
+            die("Invalid item");
+        }
+        $cart = [];
+
+        if (!empty($_SESSION['cart'])) {
+            $cart = $_SESSION['cart'];
+        }
+
+        if (empty($cart[$item])) {
+            $cart[$item] = $qty;
+        } else {
+            $cart[$item] += $qty;
+        }
+
+        $_SESSION['cart'] = $cart;
+
+        header('Location: ./?page=cart&msg=itemadded');
+        die();
+
+        break;
+    case "updatecart":
+        $item = $VARS['item'];
+        $qty = $VARS['qty'];
+
+        $cart = [];
+
+        if (!empty($_SESSION['cart'])) {
+            $cart = $_SESSION['cart'];
+        }
+
+        $cart[$item] = $qty;
+
+        if ($qty <= 0) {
+            unset($cart[$item]);
+        }
+
+        $_SESSION['cart'] = $cart;
+
+        header('Location: ./?page=cart&msg=itemupdated');
+
+        break;
+}

public/index.php

@@ -42,6 +42,9 @@ if (isset($_GET['page'])) {
                 $page = "404";
             }
             break;
+        case "cart":
+            $page = "cart";
+            break;
         case "home":
         default:
             $page = "home";

public/lib/item.php

@@ -100,11 +100,40 @@ END;
                     <button type="submit" class="btn btn-primary"><i class="fas fa-cart-plus"></i> Add</button>
                 </div>
             </div>
-            <input type="hidden" name="item" value="<?php echo $id; ?>" />
+            <input type="hidden" name="item" value="$id" />
             <input type="hidden" name="action" value="addtocart" />
         </form>
     </div>
 </div>
+END;
+        return $html;
+    }
+
+    static function cart(Item $item, int $qty) {
+        $id = $item->getId();
+        $name = $item->getName();
+        $catid = $item->getCategoryId();
+        $catname = $item->getCategoryName();
+        $price = $item->getPrice();
+        $html = <<<END
+<div class="list-group-item d-flex flex-wrap">
+    <div>
+        <h4><a href="./?page=item&id=$id">$name</a></h4>
+        <span>$$price</span>
+    </div>
+    <div class="ml-auto">
+        <form action="./action.php" method="POST">
+            <div class="input-group">
+                <input type="number" name="qty" class="form-control mb-2" placeholder="Quantity" value="$qty" />
+                <div class="input-group-addon">
+                    <button type="submit" class="btn btn-primary"><i class="fas fa-sync"></i> Update</button>
+                </div>
+            </div>
+            <input type="hidden" name="item" value="$id" />
+            <input type="hidden" name="action" value="updatecart" />
+        </form>
+    </div>
+</div>
 END;
         return $html;
     }

public/parts/cart.php

@@ -6,3 +6,32 @@
  * file, You can obtain one at http://mozilla.org/MPL/2.0/.
  */
 
+if (!defined('NICKELBOX')) {
+    die("Direct access denied.");
+}
+
+$cart = [];
+
+if (!empty($_SESSION['cart'])) {
+    $cart = $_SESSION['cart'];
+}
+
+?>
+
+<div class="container mt-4">
+    <h1 class="display-4">Cart</h1>
+
+    <div class="list-group list-group-flush">
+        <?php
+        if (count($cart) > 0) {
+            foreach ($cart as $i => $qty) {
+                echo RenderItem::cart(new Item($i), $qty);
+            }
+        } else {
+            ?>
+            <p>The cart is empty.</p>
+            <?php
+        }
+        ?>
+    </div>
+</div>