+ 0 -

+ 0 -

+ 0 -

  <p data-behavior="counter">
    <button data-behavior="increment">+</button>
    <span data-behavior-target="number">0</span>
    <button data-behavior="decrement">-</button>
  </p>
  

  $.behavior( 'counter' ).ifPresent(function( root ) {
    var state = 0;

    var updateNumber = function(number) {
      root.directTarget( 'number' ).text( number );
    };

    var handleIncrement = function() {
      updateNumber( state = state + 1 );
    };

    var handleDecrement = function() {
      updateNumber( state = state - 1 );
    };

    root.child( 'increment' ).on( 'click', handleIncrement );
    root.child( 'decrement' ).on( 'click', handleDecrement );
  });