Events

<dkl-price> is event-driven. It has no direct reference to the volume picker — instead it listens for the picker’s tier-change event and the theme’s variant-change events, and updates the price accordingly.

Listens for

discount-kit-live:volume-discount:tier-change

CustomEvent

Emitted by the volume picker. Matched by product id — a selected tier shows the discounted price, a null tier reverts to base. Coupling is by event name and product id only, with no import between the two components.

Honours the event’s updatesPrice flag: if the picker’s “Update price when a tier is selected” setting is off, <dkl-price> ignores the tier for pricing (the event still fires for other listeners).

It also reacts to the host theme’s variant-change events: on a variant change it updates the base price and re-applies the active tier, recomputing the discount off the new variant’s price (sale-priced variants included).

Emits

<dkl-price> emits a price-change event whenever its displayed price updates, plus mount / unmount lifecycle events. All bubble, so you can listen on document.

widgetId and variantId

widgetId is the app block’s id — it’s null on a web component, variantId is the current variant and updates as the shopper switches variants (not just the variant at page load).

Price change

discount-kit-live:price:change

CustomEvent

Fired whenever the displayed price changes — when a volume tier is selected or deselected, or the variant changes. Not fired on initial mount (the server-rendered price is already in the DOM), and deduped — a recompute that lands on the same price (e.g. switching to an equally-priced variant) doesn’t fire. The detail carries resource with the previous and new price, mirroring the tier event’s previousTier / currentTier:

resource: {
  widgetType: 'price'
  widgetId: string | null
  productId: number | null
  variantId: number | null
  previousPrice: PriceState | null   // null on the first change after mount
  currentPrice:  PriceState
}

type PriceState = {
  priceCents: number              // displayed price (discounted when a tier is active)
  compareAtCents: number | null   // the struck-through "before" price, or null
  discounted: boolean             // whether a volume tier is applied
  tier: VolumeDiscountTier | null // the active tier, or null
}
// VolumeDiscountTier: { index, quantity, discountAmount, discountType, unitPriceCents }

A full example payload — selecting a tier that moves the price from £20.00 to £18.00:

// event.detail.resource on price:change
{
  widgetType: 'price',
  widgetId: 'a1b2c3d4',        // the app block's id (null on a web component)
  productId: 7820000000001,
  variantId: 41200000000001,   // the current variant — updates on a variant change
  previousPrice: {
    priceCents: 2000,
    compareAtCents: null,
    discounted: false,
    tier: null
  },
  currentPrice: {
    priceCents: 1800,
    compareAtCents: 2000,      // the original price, now struck through
    discounted: true,
    tier: {
      index: 1,
      quantity: 3,
      discountAmount: 10,
      discountType: 'percentage',
      unitPriceCents: 1800
    }
  }
}

Lifecycle

The mount / unmount events fire as the instance’s behaviour attaches and tears down — handy for wiring up (and cleaning up) custom integrations per instance. Both carry a DklWidgetEventDetail resource.

discount-kit-live:widget:mount

CustomEvent

Fired once the controller has attached its behaviour to the (already server-rendered) element. resource: { widgetType, widgetId, productId?, variantId? } — productId and variantId are included when known.

discount-kit-live:widget:unmount

CustomEvent

Fired when the instance tears down — e.g. the element is removed, or the theme editor re-renders the section. Same resource shape. Use it to detach any listeners or observers you set up on mount.

// event.detail.resource on widget:mount / widget:unmount
{
  widgetType: 'price',
  widgetId: 'a1b2c3d4',        // the app block's id (null on a web component)
  productId: 7820000000001,
  variantId: 41200000000001
}

Next steps

Web ComponentsListener and MutationObserver examples for reacting to changes.

Volume PickerThe component that emits the tier-change event.