Allow preConfirm to prevent dialog closing

It would be nice to be able to keep the dialog open if some condition is not met in preConfirm logic.

Previously it was possible by returning a rejected promise, but with v. 7 it looks like the only way to prevent closing is to call swal.showValidationError.

Usage example, if I want user to confirm a destructive action:

preConfirm: function() {
  if (!confirm('Are you sure?')) {
    // possible solution - a flag that would instruct swal to keep the dialog open
    swal.keepOpened = true;
    return;
  }
  // proceed otherwise
}

As a workaround I had to do this:

onOpen: function(el) {
  var container = $(el);
  var originalConfirmButton = container.find('.swal2-confirm');
  var clonedConfirmButton = originalConfirmButton.clone();

  originalConfirmButton.hide();
  clonedConfirmButton.insertAfter(originalConfirmButton);

  clonedConfirmButton.on('click', function() {
    if (confirm('Are you sure?')) originalConfirmButton.click();
  });
}

[gverni]

@BMahabir can you provide a live example? BTW, if you want to see preConfirn in action you can have a look to this example (source code here)

[zenflow]

I didn’t suggest that initially because it would only work for sync. code.

Not sure I understand this statement. Sync and async preConfirms should work the same as of version 7.

Could it also cause result.value to be falsy in swal().then(), making it look like user clicked “Cancel”?

Nope. I had a similar concern too, but if the result of preConfirm is falsy, then the original value passed to preConfirm is used. If there is no input option, result.value will be true.

https://github.com/sweetalert2/sweetalert2/blob/8cc05c8823a50589cd735cf00f16596556a1c5aa/src/sweetalert2.js#L576-L585

Besides, if preConfirm returns false, then there will be no result at all for that case, since the swal will not complete. My concern was that you would no longer be able to use preConfirm to make the result.value a boolean (possibly false), but this was never possible, for the above reason.