Hooks for Discount Calculation

Filters for modifying discount calculation and price rounding.

Calculation Base Mode

Each rule can have a calculation_base_mode setting that determines which price the discount is calculated from:

Value	Constant	Description
current_price	CalculationBaseModes::CURRENT_PRICE	Discount from current price (after previous discounts) - default
original_price	CalculationBaseModes::ORIGINAL_PRICE	Discount always from regular price (regular_price)

Behavior Example — multiple Auto Price rules

Product: regular_price = $100
Rule 1 (Product): -20% → $80
Rule 2 (Bulk):    -5%

With calculation_base_mode = 'current_price' on Rule 2:
  → 5% of $80 = $4 → final $76 (stacks on Rule 1)

With calculation_base_mode = 'original_price' on Rule 2:
  → 5% of $100 = $5 → final $95 (overrides Rule 1, recalculated from regular_price)

When multiple Auto Price rules match the same product, they are applied in priority order (lower menu_order first). Each rule’s calculation_base_mode decides whether it stacks on the running price or restarts from regular_price. The stop_processing flag halts iteration over lower-priority rules.

Behavior Example — Auto Price + BOGO

Product: regular_price = $100
Rule 1 (Product): -20% → price = $80
Rule 2 (BOGO): -50%

With calculation_base_mode = 'current_price':
  → 50% of 80 = $40 (discounts stack)

With calculation_base_mode = 'original_price':
  → 50% of 100 = $50 (discount from original price)

Accessing the Setting in Code

use WpifyWooDiscountRule\Services\Rules;
use WpifyWooDiscountRule\Enums\CalculationBaseModes;

// Within a rule
$calc_base_mode = $rule[ Rules::CALCULATION_BASE_MODE ] ?? CalculationBaseModes::CURRENT_PRICE;

if ( CalculationBaseModes::ORIGINAL_PRICE === $calc_base_mode ) {
    // Use regular_price
    $base = $product->get_regular_price();
} else {
    // Use current price (may include other discounts)
    $base = $product->get_price();
}

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Modifying Data Before Discount Calculation

This filter allows you to modify data before the actual discount calculation.

apply_filters( 'wpify_woo_discounts_calculate_data', $data, $product, $rule, $range );

Filter Parameters

Parameter	Type	Description
$data	array	Data for discount calculation (original_price, calculation_base, discount_type, discount_value)
$product	WC_Product	Product the discount is applied to
$rule	array	Rule settings (including calculation_base_mode)
$range	array	Current discount range/tier

Usage Examples

Adjusting Discount for a Specific Category

/**
 * Increase discount for products in the "sale" category
 *
 * @param array      $data    Calculation data
 * @param WC_Product $product Product
 * @param array      $rule    Rule
 * @param array      $range   Discount range
 *
 * @return array
 */
function boost_discount_for_sale_category( $data, $product, $rule, $range ): array {
    if ( has_term( 'akce', 'product_cat', $product->get_id() ) ) {
        // Increase percentage discount by 5%
        if ( $data['discount_type'] === 'percentage' && isset( $data['discount_value'] ) ) {
            $data['discount_value'] += 5;
        }
    }
    return $data;
}
add_filter( 'wpify_woo_discounts_calculate_data', 'boost_discount_for_sale_category', 10, 4 );

Setting a Minimum Discount

/**
 * Ensure a minimum discount of 10%
 *
 * @param array      $data    Calculation data
 * @param WC_Product $product Product
 * @param array      $rule    Rule
 * @param array      $range   Discount range
 *
 * @return array
 */
function ensure_minimum_discount( $data, $product, $rule, $range ): array {
    if ( $data['discount_type'] === 'percentage' ) {
        $data['discount_value'] = max( 10, $data['discount_value'] ?? 0 );
    }
    return $data;
}
add_filter( 'wpify_woo_discounts_calculate_data', 'ensure_minimum_discount', 10, 4 );

---

Modifying the Discount Calculation Result

This filter allows you to modify the result after the discount has been calculated.

apply_filters( 'wpify_woo_discounts_calculate_product_discount', $result, $product, $rule, $range );

Filter Parameters

Parameter	Type	Description
$result	array	Calculation result (discounted_price, discount_amount, discount_percentage)
$product	WC_Product	Product
$rule	array	Rule settings
$range	array	Discount range

Usage Examples

Logging Discount Calculations

/**
 * Log all discount calculations
 *
 * @param array      $result  Calculation result
 * @param WC_Product $product Product
 * @param array      $rule    Rule
 * @param array      $range   Discount range
 *
 * @return array
 */
function log_discount_calculation( $result, $product, $rule, $range ): array {
    if ( defined( 'WP_DEBUG' ) && WP_DEBUG ) {
        error_log( sprintf(
            'Discount calculated: Product #%d, Original: %s, Discounted: %s',
            $product->get_id(),
            $result['original_price'] ?? 'N/A',
            $result['discounted_price'] ?? 'N/A'
        ) );
    }
    return $result;
}
add_filter( 'wpify_woo_discounts_calculate_product_discount', 'log_discount_calculation', 10, 4 );

---

Modifying Price Rounding

This filter allows you to modify the rounding logic of the final discounted price.

apply_filters( 'wpify_woo_discounts_round_price', $rounded_price, $original_price, $rounding_mode, $rule );

Filter Parameters

Parameter	Type	Description
$rounded_price	float	Price after rounding (according to the configured mode)
$original_price	float	Price before rounding (after discount)
$rounding_mode	string	Mode: whole, ending_99, ending_90, ending_9
$rule	array	Complete rule data

Usage Examples

Custom Rounding for VIP Customers

/**
 * Always round down for VIP customers
 *
 * @param float  $rounded_price  Rounded price
 * @param float  $original_price Price before rounding
 * @param string $rounding_mode  Rounding mode
 * @param array  $rule           Rule
 *
 * @return float
 */
function vip_rounding( $rounded_price, $original_price, $rounding_mode, $rule ): float {
    if ( current_user_can( 'vip_member' ) ) {
        return floor( $original_price );
    }
    return $rounded_price;
}
add_filter( 'wpify_woo_discounts_round_price', 'vip_rounding', 10, 4 );

Rounding to Multiples of 10

/**
 * Round price to multiples of 10
 *
 * @param float  $rounded_price  Rounded price
 * @param float  $original_price Price before rounding
 * @param string $rounding_mode  Rounding mode
 * @param array  $rule           Rule
 *
 * @return float
 */
function round_to_tens( $rounded_price, $original_price, $rounding_mode, $rule ): float {
    return round( $original_price / 10 ) * 10;
}
add_filter( 'wpify_woo_discounts_round_price', 'round_to_tens', 10, 4 );

---

Controlling Discount Application (Subscriptions)

Filter to control whether a discount should be applied. Primarily used for WooCommerce Subscriptions.

apply_filters( 'wpify_woo_discounts_should_apply_discount', $should_apply, $rule );

Filter Parameters

Parameter	Type	Description
$should_apply	bool	Default value (true)
$rule	array	Rule data including renewal_behavior

Usage Examples

Disabling Bulk Discounts on Renewals

/**
 * Never apply bulk discounts on renewal orders
 *
 * @param bool  $should_apply Default value
 * @param array $rule         Rule
 *
 * @return bool
 */
function no_bulk_on_renewals( $should_apply, $rule ): bool {
    if ( function_exists( 'wcs_cart_contains_renewal' ) && wcs_cart_contains_renewal() ) {
        if ( ( $rule['rule_type'] ?? '' ) === 'bulk' ) {
            return false;
        }
    }
    return $should_apply;
}
add_filter( 'wpify_woo_discounts_should_apply_discount', 'no_bulk_on_renewals', 10, 2 );

Available renewal behavior values:

• first_order_only - Discount only on the first order
• renewals_only - Discount only on renewal orders
• both - Discount on both (default)

---

Modifying Target Products

This filter allows you to modify the list of target products after they have been prepared.

apply_filters( 'wpify_woo_discounts_targets_prepared', $targets, $rule );

Filter Parameters

Parameter	Type	Description
$targets	array	Array of target products
$rule	array	Rule settings

Usage Example

/**
 * Exclude low-margin products from discount targets
 *
 * @param array $targets Target products
 * @param array $rule    Rule
 *
 * @return array
 */
function exclude_low_margin_products( $targets, $rule ): array {
    return array_filter( $targets, function( $target ) {
        $product_id = $target['product_id'] ?? 0;
        $margin = get_post_meta( $product_id, '_profit_margin', true );
        return $margin > 10; // Exclude products with margin below 10%
    } );
}
add_filter( 'wpify_woo_discounts_targets_prepared', 'exclude_low_margin_products', 10, 2 );

---

Modifying Subrule Metadata

This filter allows you to add custom metadata to subrules (discount tiers).

apply_filters( 'wpify_woo_discounts_subrule_metadata', $metadata, $subrule, $rule );

Filter Parameters

Parameter	Type	Description
$metadata	array	Subrule metadata
$subrule	array	Subrule data
$rule	array	Rule settings

Usage Example

/**
 * Add custom metadata for tracking
 *
 * @param array $metadata Metadata
 * @param array $subrule  Subrule
 * @param array $rule     Rule
 *
 * @return array
 */
function add_tracking_metadata( $metadata, $subrule, $rule ): array {
    $metadata['campaign_id'] = $rule['campaign_id'] ?? '';
    $metadata['applied_at'] = current_time( 'mysql' );
    return $metadata;
}
add_filter( 'wpify_woo_discounts_subrule_metadata', 'add_tracking_metadata', 10, 3 );

---

Modifying the Quantity Limit

This filter allows you to modify the maximum quantity for a discount.

apply_filters( 'wpify_woo_discounts_quantity_limit', $limit, $product, $rule );

Filter Parameters

Parameter	Type	Description
$limit	int	Quantity limit
$product	WC_Product	Product
$rule	array	Rule settings

Usage Example

/**
 * Limit quantity for wholesale customers
 *
 * @param int        $limit   Limit
 * @param WC_Product $product Product
 * @param array      $rule    Rule
 *
 * @return int
 */
function limit_wholesale_quantity( $limit, $product, $rule ): int {
    if ( current_user_can( 'wholesale_customer' ) ) {
        return min( $limit, 100 ); // Max 100 pcs for wholesale
    }
    return $limit;
}
add_filter( 'wpify_woo_discounts_quantity_limit', 'limit_wholesale_quantity', 10, 3 );

---

Fee Application Type

This filter allows you to modify the fee/discount application type in the cart.

apply_filters( 'wpify_woo_discounts_fee_application_type', $type, $rule );

Filter Parameters

Parameter	Type	Description
$type	string	Application type (fixed, percent)
$rule	array	Rule settings

Usage Example

/**
 * Change application type for specific rules
 *
 * @param string $type Application type
 * @param array  $rule Rule
 *
 * @return string
 */
function change_fee_application_type( $type, $rule ): string {
    // Use percentage for rules with the high_value tag
    if ( in_array( 'high_value', $rule['tags'] ?? [], true ) ) {
        return 'percent';
    }
    return $type;
}
add_filter( 'wpify_woo_discounts_fee_application_type', 'change_fee_application_type', 10, 2 );

---

Stacked Selection Price (Service Method)

Compute the per-item discounted prices for a synthetic product selection — useful for custom selectors, blocks or templates that need to display the price of a not-yet-added-to-cart selection with all stacked price-modifying rules applied (Product + Bulk + Bundle).

Unlike a filter, this is a service method on StackedPriceResolver. Resolve it through the plugin’s DI container:

use WpifyWooDiscountRule\Modules\DiscountRules\Utils\StackedPriceResolver;

$resolver = wpify_woo_discount_rules_container()->get( StackedPriceResolver::class );
$result   = $resolver->compute_selection_price( $lines, $options );

Input — $lines

A list of selection lines. Each line is an associative array:

Key	Type	Required	Default	Notes
product	WC_Product	one of these two	—	Used directly when present (no DB roundtrip).
product_id	int	one of these two	—	If product missing, the service calls wc_get_product( product_id ).
qty	int	no	1	qty <= 0 → line silently skipped.

Normalisation rules (applied in order):

1. If both product and product_id are provided, product wins.
2. If neither is provided → line silently skipped.
3. If wc_get_product() returns false for product_id → line silently skipped.
4. Duplicate products across multiple lines (same effective product_id) → merged, qty summed.

Input — $options

Key	Type	Default	Effect
include_cart	bool	false	When true, the current WC()->cart content is merged into the qualifying pool. Cart entries contribute to Bulk tier counts and Bundle slot matching, but never appear in the per-item output.

Return Value

Always an array (never null). For empty input or input where every line is silently skipped:

[
    'items'  => [],
    'totals' => [
        'regular_total'    => 0.0,
        'discounted_total' => 0.0,
        'savings'          => 0.0,
    ],
]

For a non-empty selection:

[
    'items' => [
        123 => [
            'product'               => WC_Product,
            'product_id'            => 123,
            'qty'                   => 2,
            'unit_regular_price'    => 1000.00,
            'unit_discounted_price' => 720.00,
            'line_regular_total'    => 2000.00,
            'line_discounted_total' => 1440.00,
            'savings'               => 560.00,
        ],
        // ... one entry per unique sent product
    ],
    'totals' => [
        'regular_total'    => 2000.00,
        'discounted_total' => 1440.00,
        'savings'          => 560.00,
    ],
]

items is keyed by product_id so templates can index directly ($result['items'][ 123 ]). PHP preserves insertion order, so iteration yields products in the order they first appeared in $lines. All numeric values are rounded to wc_get_price_decimals() precision.

The service returns raw numbers only — tax presentation (wc_get_price_to_display()) and HTML formatting (wc_price(), wc_format_sale_price()) are the template’s responsibility.

Usage Example

use WpifyWooDiscountRule\Modules\DiscountRules\Utils\StackedPriceResolver;

/**
 * Render the bundle selector price inside a custom template.
 *
 * @param WC_Product[] $selected_products Products the customer picked.
 */
function render_bundle_selector_price( array $selected_products ): void {
    $resolver = wpify_woo_discount_rules_container()->get( StackedPriceResolver::class );

    $lines = array_map(
        fn( WC_Product $p ) => [ 'product' => $p, 'qty' => 1 ],
        $selected_products
    );

    $result = $resolver->compute_selection_price( $lines );

    if ( empty( $result['items'] ) ) {
        return;
    }

    echo wc_format_sale_price(
        wc_price( $result['totals']['regular_total'] ),
        wc_price( $result['totals']['discounted_total'] )
    );
}

Mode 2 (include_cart = true)

Pass include_cart to compute prices as if the selection were added to the current cart:

$result = $resolver->compute_selection_price(
    $lines,
    [ 'include_cart' => true ]
);

• Rule triggers see combined quantity (sent + cart). A Bulk tier or Bundle slot requirement can qualify based on the merged pool even when the sent selection alone would not satisfy it.
• Rule discounts are applied only to sent products — cart-only entries never appear in items[].

Migration from wpify_woo_discounts_bundle_set_price

The filter wpify_woo_discounts_bundle_set_price and the public method Bundle::calculate_set_price() have been removed and are replaced by this service method.

// OLD — no longer works
$price = apply_filters(
    'wpify_woo_discounts_bundle_set_price',
    null,
    $selected_products,
    [ 'application_mode' => 'auto_price' ]
);
if ( null === $price ) { return; }
echo $price['html'];

// NEW
use WpifyWooDiscountRule\Modules\DiscountRules\Utils\StackedPriceResolver;

$resolver = wpify_woo_discount_rules_container()->get( StackedPriceResolver::class );
$lines  = array_map( fn( $p ) => [ 'product' => $p, 'qty' => 1 ], $selected_products );
$result = $resolver->compute_selection_price( $lines );
if ( empty( $result['items'] ) ) { return; }
echo wc_format_sale_price(
    wc_price( $result['totals']['regular_total'] ),
    wc_price( $result['totals']['discounted_total'] )
);

The new method applies all active price-modifying rules (Product + Bulk + Bundle), not just Bundle. The output is per-item (keyed by product_id) plus aggregate totals, instead of the previous Bundle-specific payload.

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Where to Place the Code

You can add custom functions either in your child theme’s functions.php or using the Code Snippets plugin.