<ul id="todo">
  <li rv-each-todo="list.todos">
    <input type="checkbox" rv-idx="todo.idx" rv-checked="todo.done">
    <span>{ todo.summary }</span>
  </li>
<ul>

<input rv-editing-idx="133"></input>

<ul id="todo">
  <li rv-each-todo="list.todos">
    <input type="radio" rv-idx="todo.idx" rv-checked="todo.done" name="todo" rv-on-change="list.change">
    <span>{ todo.summary }</span>
  </li>
<ul>

<input id="changeele" rv-value="summary"></input>

var ele = document.getElementById('changeele');
var eleBinding = rivets.bind(ele, {});

var list = {
    "todos": [
            {"idx":133, "done":true,"summary":"Eat"},
            {"idx":25, "done":false,"summary":"Code"},
            {"idx":33, "done":false,"summary":"Sleep"},
            {"idx":24, "done":false,"summary":"Repeat"}
        ],
    "change": function(event, scope) {
        eleBinding.unbind();
        eleBinding = rivets.bind(ele, scope.list.todos[scope.index]);
    }
 }

rivets.bind(document.getElementById('todo'), {list: list})