nurl/public/javascripts/shorten.js

$('#btn-shorten').on('click', function(){
    console.log('Click');

  $.ajax({
    url: '/api/v1/shorten',
    type: 'POST',
    dataType: 'JSON',
    data: {url: $('#url-field').val()},
    success: function(data){
        var resultHTML = '<a class="result" href="' + data.shortUrl + '">'
            + data.shortUrl + '</a>';
        $('#link').html(resultHTML);
        $('#link').hide().fadeIn('slow');
    }
  });

});