PriceCalculator Form Field

PriceCalculatorField is a ListField subclass that renders a dropdown of available pricing calculator strategies. The built-in standard calculator is always present. Additional calculators are registered by plugins via the onJ2CommerceGetPricingCalculators event, which is collected and returned by ProductHelper::getPricingCalculators().

Key Classes

Class	File	Purpose
PriceCalculatorField	administrator/components/com_j2commerce/src/Field/PriceCalculatorField.php	Renders the calculator dropdown
ProductHelper	administrator/components/com_j2commerce/src/Helper/ProductHelper.php	getPricingCalculators() — collects calculators via event
J2CommerceHelper	administrator/components/com_j2commerce/src/Helper/J2CommerceHelper.php	plugin()->event() dispatcher shortcut

Built-in Calculators

Value	Language key
standard	COM_J2COMMERCE_PRODUCT_PRICING_CALCULATOR_STANDARD

Plugin Event: onJ2CommerceGetPricingCalculators

ProductHelper::getPricingCalculators() fires this event after seeding the standard entry. Plugins receive the calculators array by named argument and append their own entries.

Detail	Value
Event name	onJ2CommerceGetPricingCalculators
Fired by	ProductHelper::getPricingCalculators()
Named argument	calculators — the array to which plugins append
Plugin group	j2commerce

Registering a Custom Pricing Calculator

// File: plugins/j2commerce/app_yourplugin/src/Extension/AppYourPlugin.php

declare(strict_types=1);

namespace J2Commerce\Plugin\J2Commerce\App\YourPlugin\Extension;

use Joomla\CMS\Language\Text;
use Joomla\CMS\Plugin\CMSPlugin;
use Joomla\Event\Event;
use Joomla\Event\SubscriberInterface;

class AppYourPlugin extends CMSPlugin implements SubscriberInterface
{
    public static function getSubscribedEvents(): array
    {
        return [
            'onJ2CommerceGetPricingCalculators' => 'onJ2CommerceGetPricingCalculators',
        ];
    }

    public function onJ2CommerceGetPricingCalculators(Event $event): void
    {
        $calculators = $event->getArgument('calculators', []);
        $calculators['tiered'] = Text::_('PLG_J2COMMERCE_APP_YOURPLUGIN_CALCULATOR_TIERED');
        $event->setArgument('calculators', $calculators);
    }
}

ProductHelper::getPricingCalculators() passes the array by value as a named key ('calculators'). Use $event->setArgument('calculators', ...) to return the modified array.

Error Handling

If ProductHelper::getPricingCalculators() throws an exception (e.g. during a failed plugin import), PriceCalculatorField::getOptions() catches it and enqueues an admin error message using COM_J2COMMERCE_ERROR_LOADING_PRICING_CALCULATORS. The dropdown will contain only the options already added by parent::getOptions() (any <option> tags in the field XML).

XML Usage

<!-- File: administrator/components/com_j2commerce/forms/product.xml (example) -->

<form addfieldprefix="J2Commerce\Component\J2commerce\Administrator\Field">
    <fieldset name="pricing">
        <field
            name="pricing_calculator"
            type="PriceCalculator"
            label="COM_J2COMMERCE_FIELD_PRICING_CALCULATOR_LABEL"
            description="COM_J2COMMERCE_FIELD_PRICING_CALCULATOR_DESC"
            default="standard"
        />
    </fieldset>
</form>

XML Attributes

Attribute	Type	Default	Description
type	string	—	Must be PriceCalculator
default	string	standard	Preselected calculator key
required	bool	false	Mark field as required

All standard Joomla ListField attributes also apply.

Usage in Plugin Forms

A pricing extension plugin can expose its calculator in its own config.xml without touching core forms:

<!-- File: plugins/j2commerce/app_yourplugin/config.xml -->

<?xml version="1.0" encoding="UTF-8"?>
<config>
    <fields name="params">
        <fieldset name="basic" label="COM_PLUGINS_BASIC_FIELDSET_LABEL">
            <field
                name="default_calculator"
                type="PriceCalculator"
                addfieldprefix="J2Commerce\Component\J2commerce\Administrator\Field"
                label="PLG_J2COMMERCE_APP_YOURPLUGIN_FIELD_CALCULATOR_LABEL"
                description="PLG_J2COMMERCE_APP_YOURPLUGIN_FIELD_CALCULATOR_DESC"
                default="standard"
            />
        </fieldset>
    </fields>
</config>

Related

• ProductType Field — Dropdown extended by onJ2CommerceGetProductTypes
• VariantPrice Field — Currency-prefixed price input for variants
• Advanced Pricing — Price rule architecture