One-way data-binding

data-binding.js

 function bind(expr, data, el){
    el.render = render.bind(null, expr, data, el);
    return on('squirt.els.render', function(){
      el.render();
    });
  };

  function render(expr, data, el){
    var match, rendered = expr;
    expr.match(/{{[^}]+}}/g).map(function(match){
      var val = data[match.substr(2, match.length - 4)];
      rendered = rendered.replace(match, val == undefined ? '' : val);
    });
    el.textContent = rendered;
  };

  function on(bus, evts, cb){
    if(cb === undefined){
      cb = evts;
      evts = bus;
      bus = document;
    }
    evts = typeof evts == 'string' ? [evts] : evts;
    var removers = evts.map(function(evt){
      bus.addEventListener(evt, cb);
      return function(){
        bus.removeEventListener(evt, cb);
      };
    });
    if(removers.length == 1) return removers[0];
    return removers;
  };