Uncaught (in promise) cancel using SweetAlert2

Question

how do I properly escape the cancel button without throwing an error when using promises? My code throws an alert confirmation with a required checkbox. the code executes as it should to the user, but it throws an error in the console window:

Uncaught (in promise) cancel

//validation logic all passes...Now proceed to...

 else
    {

//determine and parse Discounts

 var myLookup = document.getElementsByName("myLookup")[0].value;
$.post( "findthem.php", {myLookup: myLookup })
  .done(function(json_data){
     var theResponse1 = $.parseJSON(json_data);
     myDiscountRate = theResponse1['ourDiscountFound'];

    }).then( function(callback){

    priceRate = priceRate * (1 - (.01 * myDiscountRate));
    newRate = priceRate.toFixed(2);
}

swal({
  title: "Confirm",
  input: 'checkbox',
  inputValue: 0,
  type: "warning",
  inputPlaceholder: 'I agree to <a href="#blahblahMore"></a> Your new Rate is :'+newRate,
  showCancelButton: true,
  confirmButtonText: 'Confirm',
  showLoaderOnConfirm: true,
  preConfirm: function(result) {
    return new Promise(function(resolve, reject) {
      if (result) {
        $.post("my.php", {
          Data: data
        })
        .done(
          function(json_data) {
            var data_array = $.parseJSON(json_data);
            var moreDetails = '';
            var resulting = 'error';
            var details = "Transaction Declined"
            if (data_array["trxApproved"] == true) {
              resulting = 'success';
              details = "Confirmed"
              moreDetails = "<br>Approved<b>" + data_array["approved"] + "</b>" +
                "<br>Details Code: <b>" + data_array["detailsCode"] + "</b>";
            }
            swal({
              type: resulting,
              title: details,
              html: "<h1>Details: </h1>" + data_array["messagetext"] + moreDetails
            });
          }
        );
        resolve();
      } else {
          reject('You must agree to our Terms & Conditions ');
      }
    });
  },
  allowOutsideClick: false
  }).then(function(json_data) {

  })
});

Answer 1

Update (Jan 2017): This issue has been fixed in v7: v7 upgrade guide ↗

---

You need to add a rejection handler to the Promise. Alternatively, you can use .catch(swal.noop) as a quick way to simply suppress the errors:

swal('...')
  .catch(swal.noop);

---

PS. the package you're using is called SweetAlert2, not SweetAlert. In future questions please mention it so you can get more relevant answers.

Answer 2

SweetAlert2 rejects the result promise when the cancel button is pressed. You can handle that:

swal({
  …
}).then(function(json_data) {
  …
}, function(dismiss) {
  if (dismiss === 'cancel') { // you might also handle 'close' or 'timer' if you used those
    // ignore
  } else {
    throw dismiss;
  }
})

If you don't need to do anything with the json_data, you might also use the catch method.

Answer 3

new Promise(function(resolve, reject) { is not necessary. $.post() returns a jQuery promise object.

Possible solution substitutes Promise.reject() for new Promise() constructor; removed .then() that was placed as an option to first swal() call; pattern appears to expect a Promise to be returned from preConfirm, though not certain what value is expected to be returned from .done() other than json_data.

swal({
  title: "Confirm",
  input: 'checkbox',
  inputValue: 0,
  type: "warning",
  inputPlaceholder: 'I agree to <a href="#blahblahMore"></a>',
  showCancelButton: true,
  confirmButtonText: 'Confirm',
  showLoaderOnConfirm: true,
  preConfirm: function(result) {
      if (result) {
        return $.post("my.php", {
          Data: data
        })
        .done(
          function(json_data) {
            var data_array = $.parseJSON(json_data);
            var moreDetails = '';
            var resulting = 'error';
            var details = "Transaction Declined"
            if (data_array["trxApproved"] == true) {
              resulting = 'success';
              details = "Confirmed"
              moreDetails = "<br>Approved<b>" + data_array["approved"] + "</b>" +
                "<br>Details Code: <b>" + data_array["detailsCode"] + "</b>";
            }
            swal({
              type: resulting,
              title: details,
              html: "<h1>Details: </h1>" + data_array["messagetext"] + moreDetails
            });
          }
        );
      } else {
          return Promise.reject('You must agree to our Terms & Conditions ');
      }
  },
  allowOutsideClick: false
});

Answer 4

you will need to catch the action for cancel

swal({
  title: 'Are you sure?',
  text: "You won't be able to revert this!",
  type: 'warning',
  showCancelButton: true,
  confirmButtonColor: '#3085d6',
  cancelButtonColor: '#d33',
  confirmButtonText: 'Yes, delete it!'
}).then(function(json_data) {
  //delete item
}, function(dismiss) {
  if (dismiss === 'cancel' || dismiss === 'close') {
    // ignore
  } 
})