will_submit_form
Description:
This signal is emitted when form will imminently be submitted.
It can no longer be cancelled. This event always occurs immediately before a form is submitted to its target, so use this event to reliably detect when a form is submitted. This signal is emitted after will_send_submit_event if that signal is emitted.
Parameters:
| form |
the Value to be submitted, which will always correspond to an HTMLFormElement |
| source_frame |
the Frame containing the form to be submitted |
| target_frame |
the Frame containing the form's target, which may be the same
as |