Why doesn't API_callback work after FAPI.UI.showPayment?

Question

Classmates

With the flash plugin disabled in the browser, when using the FAPI.UI.showPayment JavaScript API method, we get the Uncaught TypeError: c.__FAPI__CallBack is not a function error.
Tested in latest Chrome.

Answer 1

Problem with __FAPI__CallBack solved

Answer 2

This also happens in Firefox, I suspect it also happens in Oper. And it is checked up on an example from the documentation. It’s just that those who developed the JS API_callback, to use censorship, didn’t think well how to do it. It was necessary to insert API_callback into FAPI.init as the fifth parameter, after the error handler. They have thought up to be confused with global functions. Hence 1,000,000 glitches.
The same problem will be if the payment is made automatically (without a confirmation window) and the user closes the payment window not by the close button, but by clicking on the button in the upper right of the window.
As a variant of the timer solution, ask the application server about the result of the payment.