example_button.js

$.engineer.define('example_button', {

  defaults: { color: '#336699', innerText: "This element" },

  structure: function(options) {
    var div = $('<div/>', {
      css: {
        'text-align':'center', 'background':options.color, 'color':'white', 
        'padding':'5px', 'margin':'5px', 'width': '140px', 'display': 'inline'
      },
      html: options.innerText
    });

    return div;
  },

  behavior: function(options) {
    var self = this;
    
    self.click(function() {
      self.animate({ opacity: 0.4 }, 1500 );
    });
  }
});