MaxtDesign

Features

Two Companion Modes

Required Companions

Force a selection before add-to-cart. The customer picks one product (or multiple, if their role has multi-select access) from a configured list before they can add the parent to the cart.

  • Display: Radio buttons (all options visible) or dropdown (compact)
  • Single-select is default; multi-select is granted by user role under WooCommerce settings
  • Cart line item shows the relationship: Required for [parent]
  • Removing the parent from the cart cascades the removal — the required companion comes out with it
  • Required quantity is read-only in the cart; the customer cannot adjust it independently

    • Add-on Companions

    Optional checkbox selection. The customer can pick zero, one, or many add-ons. Conflict groups stop the customer from picking incompatible add-ons.

  • Display: checkboxes with per-option price and View product link
  • Cart line item shows: Add-on for [parent]
  • Add-on quantity is editable in cart (unlike required)
  • Removing the parent removes its add-ons by default

    • Automatic Quantity Matching

    When the customer adds N of the parent, N of the required companion are added automatically:

  • Parent: 5 → required companion: 5
  • Add to cart again with parent qty 3 → required companion increases to 8

    • If the customer separately adds the same product as a standalone item (or it was already in cart), the plugin tracks the split:

  • Required: 5 — driven by parent quantity, read-only
  • Extra: 2 — added independently, editable

    • The cart shows the breakdown so the customer understands why the quantity isn't directly editable.

    Conflict Groups (Add-ons Only)

    Tag add-ons with a short key like voltage or size. The plugin prevents the customer from selecting two add-ons that share the same key.

    Example: a power tool with three battery options. Tag all three with voltage. The customer can pick at most one. Useful when add-ons are mutually exclusive variants of the same supporting product.

    Pricing Display

    Per-product display options for the companion selection UI:

  • Per-option price — each companion lists its own price next to the selection control
  • Combined total — the parent page shows a running total of (parent price × parent qty) + (selected companions × parent qty)
  • Both — per-option price next to each option AND a running total at the bottom

    • The running total updates live as the customer changes their selection.

    Separate Line Items, Separate SKUs

    This is the operational backbone of the plugin and the reason it works for fulfillment teams.

  • Parent and companion are separate line items in the cart and the order
  • Each carries its own SKU, set independently in the product editor
  • Inventory deducts from each product's stock independently
  • Relationship is preserved in line item meta (_mcp_is_required / _mcp_is_optional / _mcp_parent_product_id / _mcp_group_id) and rendered as a label in cart and admin order detail

    • Your warehouse picks two SKUs, not one. Your accounting books two products at their actual prices. Your reporting sees real volume on the companion.

    HPOS Compatibility

    The plugin declares HPOS compatibility on activation via FeaturesUtil::declare_compatibility('custom_order_tables', __FILE__, true) and uses WooCommerce order APIs ($order->get_meta(), $order->update_meta_data(), $item->add_meta_data()) throughout — never get_post_meta() against the order ID.

    Both legacy storage and the new HPOS tables are supported with no configuration.

    Caching

    The requirements lookup (which companions does this parent have configured) is cached in a 1-hour WordPress transient. The cache is automatically invalidated when:

  • A product with companion config is saved
  • A companion product's stock status changes
  • An order is completed (so out-of-stock-aware lookups stay accurate)

    • Manual cache flush is available in Tools if you need it.

    Translation Support

    The plugin is translation-ready with the maxtdesign-companion-products text domain and a .pot template at languages/maxtdesign-companion-products.pot.

    ConfigurationDeveloper Guide