ASP.NET MVC - How to prevent double click submit with jquery.validate.unobtrusive lib?

Question

I need to avoid the double click submitting behavior. I'm using the client validation with the unobtrusive library. I have the following code for avoiding the double clic:

jQuery.fn.preventDoubleSubmit = function () {
         var alreadySubmitted = false;
         return jQuery(this).submit(function () {

             if (alreadySubmitted)
                 return false;
             else {
                 alreadySubmitted = true;
             }
         });
     };

     jQuery('form').preventDoubleSubmit();

Unfortunately, if my form has some validable fields (for example, a required field), the code above is still being fired, hence, even if I correct any mistakes on the form, I won't be able to submit it again.

How can I fire the double click code after the validation has been succesfully done?

Answer 1

You can also use the JQuery One event.

I have found that I could get past most guards against double-clicks by double-clicking fast. Using the one event is the only true way to make sure the event is only fired once. I don't think this technique will work "out of the box" with an input type=submit tag. Instead, you can simply use an input type=button or JQueryUI's .button().

$("#submitButton").one("click", function(event) {
   $('#theForm').submit();
});

If you need to re-wire the event on a validation error (or other circumstance), I recommend that you create a function for the event handler. The function isn't necessary in this example because all the event handler does is submit the form, but in more complicated scenarios you may want to avoid repeating yourself.

function submitClick(event) {
   $('#theForm').submit();
}

$("#submitButton").one('click', function(event) {
   submitClick(event);
});

// This handler will re-wire the event when the form is invalid.
$('#theForm').submit(function(event) {
   if (!$(this).valid()) {
      event.preventDefault();
      $('#submitButton').one('click', function(event) { submitClick(event); });
   }
});

You could obviously add the disabling code here if you wanted to give feedback to the user that the button doesn't work anymore. One great side-effect of using the One event is that you don't actually have to make the button disabled, you can use a style of your own.

function submitClick(event) {
   $('#submitButton').addClass('disabledButton');
   $('#theForm').submit();
}

$("#submitButton").one('click', function(event) {
   submitClick(event);
});

// This handler will re-wire the event when the form is invalid.
$('#theForm').submit(function(event) {
   if (!$(this).valid()) {
      event.preventDefault();
      $('#submitButton').one('click', function(event) { submitClick(event); });
      $('#submitButton').removeClass('disabledButton');
   }
});

JQuery One Event: http://api.jquery.com/one/