knockout validation multiple messages

Question

I have the following custom validtion rule for a voucher code which works and goes off to the server and validates my voucherCode correctly.

However there's 6 different failing states for a voucher - out of date, already redeemed, user not allowed etc etc.

I set the voucher message in the ajax response but this doesn't get propagated to the validation message.

Is it possible to have multiple messages for a single validation rule and change the message based on the result?

I couldn't find anything in the docs.

this.voucherMessage = "blah blah";
this.voucherCode = ko.observable("").extend({
  validation: {
    async: true,
    validator: function(val, params, callback) {
      var voucherCode;
      voucherCode = val.replace("-", "");
      return $.ajax({
        url: constantsRoutes.vouchers.getInfo(voucherCode),
        type: 'GET',
        success: callback
      }).done(function(response, statusText, xhr) {
        var isValid;
        _this.voucherDetails.setVoucher(response);
        _this.voucherMessage = _this.voucherDetails.voucherState.display();
        isValid = _this.voucherDetails.voucherState.state() === 0;
        return callback(isValid);
      });
    },
    message: this.voucherMessage
  }

Answer 1

I should've read the source code in the first place - might be useful for someone else though

callback({
  isValid: isValid,
  message: _this.voucherDetails.voucherState.display()
});

This does the trick!