About how to use JavaScript to intercept form submit

About how to use JavaScript to intercept form submit
 
Posted on winder
 
In the near future, we need to use JS scripts to intercept the form submit method on the page to modify the request URL when the page is implicitly submitted. The simple implementation is as follows:
 
Var oldSubmit;
Var form = document. forms [0];
If (form! = Null & form! = 'Undefined '){
// Back up the submit Function
Form. oldSubmit = form. submit;
// Override the submit function for interception
Form. submit = function (){
// The operation before submission ..
// Submit the original function
Form. oldSubmit ();
}
}
The above code will be intercepted when it is first executed during page loading. The onsubmit event can be monitored when the submit button is used for display. There are no major problems with this method.