(function () {
    var decodeHtmlEntities = function (value) {
        var textarea = document.createElement('textarea');
        textarea.innerHTML = String(value || '');

        return textarea.value;
    };

    var handleSubmit = function (event) {
        var target = event.target;

        if (!(target instanceof HTMLFormElement)) {
            return;
        }

        var message = decodeHtmlEntities(target.getAttribute('data-confirm-message') || '');

        if (!message) {
            return;
        }

        if (!window.confirm(message)) {
            event.preventDefault();
        }
    };

    document.addEventListener('submit', handleSubmit, true);
})();