showModal: function (e) {
  var handle = $(e.currrentTarget).data('product-handle');

  if (!handle) {
    this.renderModal():
  else {
    this.fetchProduct(handle, this.renderModal);
}

fetchProduct: function (handle, callback) {
  var self = this,
      product = this.model.get('products')[handle];

  if (product) {
  this.model.set('product', product);
    callback(product);
  else {
    $.json('' + handle + '.js', function (response, data, text_status) {
      self.model.set('product', product);
      callback(response);
    });
}


var product = async this.fetchProduct(handle);