Perform different functions when submitting a form, validating fields, depending on which action button is clicked

In the same form that contains more than 1 action button, I want to validate the fields on all buttons. In other words, each of the buttons is of type submit and each of them must trigger a different function when submitting the form.

You can set different flags depending on which button is pressed and check these flags in the form Submit event.

How can I check if a certain button has been pressed?

In the button Click event.

Yeah, set a boolean (or other) field in the click event of the buttons. Then check if that field is set or not in the Submit event of the form.