Cart

This class is initialized by miniShop2::initialize() and must implement the msCartInterface interface.

Required interface methods:

• initialize — Initializes the class in the context. Can load scripts and styles.
• add — Adds a product to the cart; id parameter is required.
• remove — Removes a product from the cart; key parameter is required
• change — Changes product quantity in the cart; key and count are required
• clean — Full cart clear
• status — Returns cart status: total cost, weight and product count
• get — Returns the full cart contents
• set — Overwrites cart contents with the given cart array

Of course, the package includes the standard msCartHandler class that implements these methods and adds a few of its own for responding to requests. You can extend it or implement the interface yourself.

You can set your class for the context in the ms2_cart_handler_class system setting. See the services section for registering services.

Initialization

if ($miniShop2 = $modx->getService('miniShop2')) {
  // Initialize the class in the current context
  $miniShop2->initialize($modx->context->key);

  print_r($miniShop2->cart->add(5)); // Add product with id = 5 and print the response
  print_r($miniShop2->cart->get()); // Get and print cart contents
  print_r($miniShop2->cart->status()); // Get and print cart status
}

After initializing the miniShop2 class, the cart and all its methods are available in $miniShop2->cart. Since the class name comes from system settings, each context can have its own cart.

You can configure msCartHandler at initialization:

// Initialize the class in the current context
$scriptProperties = array(
  'json_response' => true, // return responses in JSON
  'max_count' => 1000, // max products to add at once
  'allow_deleted' => false, // do not add products with deleted = 1 to cart
  'allow_unpublished' => false, // do not add products with published = 0 to cart
);
$miniShop2->initialize($modx->context->key, $scriptProperties);

You cannot work with the cart directly, only through the class methods.

System events

The msCartHandler class fires certain events when working with the cart. Here they are as a plugin template:

<?php
switch ($modx->event->name) {
  // Add product events
  case 'msOnBeforeAddToCart': break; // receives $product, $count, $options and $cart
  case 'msOnAddToCart': break; // receives $key and $cart

  // Remove product from cart
  case 'msOnBeforeRemoveFromCart': break; // receives $key and $cart
  case 'msOnRemoveFromCart': break; // receives $key and $cart

  // Change quantity
  case 'msOnBeforeChangeInCart': break; // receives $key, $count and $cart
  case 'msOnChangeInCart': break; // receives $key, $count and $cart

  // Clear cart
  case 'msOnBeforeEmptyCart': break; // receives $cart
  case 'msOnEmptyCart': break; // receives $cart
}

All methods receive the $cart object — the msCartHandler class instance with all its methods.

The $key variable is the cart item key, formed as:

md5($id . json_encode($data));
// where $id is the product id and $data is the parameters array sent when adding

The $count variable is the product quantity, a number.

Examples

To change a product before adding it, use the msOnBeforeAddToCart event, which has the $product object.

case 'msOnBeforeAddToCart':
  $product->set('new_price', 5555);
  break;

You can do anything with the product, even save a new price with $product->save();. This event also has the $data array — extra parameters sent by the user when adding to cart. It can contain color, size, or anything else. If you change it, the product will be added with a different $key.

Now change the product price after adding. In this event we no longer have the product, only the cart and key:

case 'msOnAddToCart':
  $tmp = $cart->get();
  $tmp[$key]['price'] = 1000;
  $cart->set($tmp);
  break;

You can change cart contents in any event; $cart is always available.