callbacks.md
Callbacks
Callback functions passed in the options object to Finix.PaymentForm(). Each callback fires in response to a specific form lifecycle event.
Fires once when the Payment Form iframe finishes loading. Takes no parameters.
onLoad: function () { ... }
Use onLoad to show UI that depends on the form being ready — for example, enabling a custom submit button or hiding a loading spinner.
Fires every time the form state changes — field values, validation errors, focus and blur events, card brand detection, and payment method switching.
onUpdate: function (state, binInformation, hasErrors) { ... }
| Parameter | Type | Description |
|---|---|---|
state |
object |
Form state including metadata about which inputs are valid, dirty, or focused — does not expose payment data |
binInformation |
object |
High-level BIN data such as BIN number and card brand |
hasErrors |
boolean |
true if the form currently has validation errors — useful for enabling or disabling a custom submit button |
Fires when the form is submitted. Providing onSubmit in the options automatically renders a submit button inside the form.
onSubmit: function (error, response) { ... }
| Parameter | Type | Description |
|---|---|---|
error |
`object | null` |
response |
`object | null` |
Use onSubmit when you want the form to render and manage its own submit button. For a custom button outside the form, use form.submit() method instead.
See Token Response for the full response shape.