RestroPress Addon Quantity

Addon Quantity lets a customer choose how many of each add-on item they want, instead of only ticking it on or off. For example, a customer can order three portions of an extra topping while the main menu item stays at quantity one. You switch the feature on per parent Add-on Group, so some groups can use quantities while others keep the standard checkbox or radio behaviour.

It is meant for restaurants whose add-ons are countable (extra toppings, sauces, sides) and who want the price and the order record to reflect the count.

Requirements#

• RestroPress, active. The extension shows an admin error and deactivates itself if restropress/restro-press.php is not active.
• It uses filters and actions that are present in RestroPress 3.4.x (rp_food_addon_column_extra_html, rpress_purchase_receipt_after_qantity_table, the rpress_addon_validation JavaScript event). The plugin header does not state a minimum RestroPress version.
• Version 1.2.4 of this extension is documented here. The readme lists "Requires at least: 4.0" for WordPress and "Tested up to: 7.1".

Installation#

1. Go to Plugins › Add New › Upload Plugin, choose the extension ZIP and select Install Now.
2. Select Activate.

This extension contains no licence field and no update-check code, so there is no licence key to enter for it. Updates are not handled by the extension itself.

Settings#

The extension adds one option to the edit screen of a parent Add-on Group.

1. Go to Menu Items › Addons and edit a parent Add-on Group (a top-level term, not one of the add-on items listed under it).
2. Find the field labelled Addon Quantity and tick the checkbox Enable This Option For Use Custom Addon Quantity.
3. Select Update.

Setting	What it does	Default
Addon Quantity (per parent Add-on Group)	Shows a minus button, a quantity box and a plus button next to every add-on item in that group. Stored as the term meta _quantity.	Off

The field only appears on parent groups. Child add-on items (terms that have a parent) do not show it, and the quantity controls of a group apply to all of its add-on items.

How it works#

Customer

1. The customer opens a menu item that has an Add-on Group with quantity enabled.
2. Next to each add-on item the price is followed by a - button, a read-only quantity box that starts at 1, and a + button.
3. Pressing + or - changes the quantity (never below 1), ticks the add-on automatically, and recalculates the add-on price as unit price multiplied by quantity. The live price in the popup is refreshed.
4. The same controls appear when the customer edits a cart item.
5. If the Add-on Group has a minimum or maximum number of add-ons, the check counts the total quantity of the ticked add-ons in that group, not the number of ticked boxes. For example, a maximum of 3 allows one add-on at quantity 3 but not two add-ons at quantity 2 each.

Restaurant

The quantity is carried in the add-on's cart data. In the purchase receipt email the extension prints the add-on quantity in the quantity column, under the item quantity.

Developer reference#

The extension does not define its own hooks. It attaches to the following RestroPress hooks.

Hook	Type	Parameters	Purpose
rp_food_addon_column_extra_html	filter	$child_addon_id, $get_addon_price, $addon_id, $child_addon_slug	The extension prints the +/- controls from this callback when the parent group has _quantity set to 1.
rpress_purchase_receipt_after_qantity_table	action	$addon_item	Prints the add-on quantity in the receipt email. The hook name is spelled "qantity" in RestroPress itself.
addon_category_edit_form_fields and edited_addon_category	WordPress taxonomy actions	term object / term ID	Render and save the Addon Quantity checkbox.
rpress_addon_validation	jQuery event	customValidation with element, minAddons, maxAddons, isValid	Replaces the count of ticked add-ons with the total quantity when a group uses quantity controls.

To read whether a group uses quantities in your own code:

$uses_quantity = '1' === (string) get_term_meta( $addon_category_id, '_quantity', true );

Troubleshooting#

• The checkbox is missing when editing an add-on. It only shows on parent groups. Open the top-level group instead.
• No +/- buttons on the storefront. Check that the group's checkbox is saved, and clear any page, object or minified-script cache so rpress_addon_quantity.js loads.
• Notice "RestroPress Addon Quantity requires RestroPress plugin..." RestroPress is not active under the folder name restropress. The extension deactivates itself when this check fails.
• Cannot go below 1. The quantity box has a floor of 1. To remove the add-on, untick it.

Changelog highlights#

• 1.2.4 (06-03-2026): fixed the cart price when decreasing add-on quantity in the edit popup; fixed quantity sync for add and edit cart flows; added nonce and capability checks when saving the setting.
• 1.2.3 (13-11-2025): quantity validation with minimum and maximum values.
• 1.2.2 (03-09-2025): design compatibility for RestroPress 3.2.