RadioNodeList polyfill

polyfill.js

/*
  demo :- http://jsfiddle.net/termi/pyFXW/

  Implements RadioNodeList :- http://www.whatwg.org/specs/web-apps/current-work/multipage/common-dom-interfaces.html#radionodelist

  Implementation just adds `.value` as a property to `NodeList`.

  Requires ES5 shim and ES5 shimmable browser. (Modern and IE8)
*/
;(function () {
    var form = document.createElement("form")
        , _NodeList_prototype_
    ;

    form.innerHTML = "<input type=radio name=t value=1><input type=radio checked name=t value=2>";

    if(form["t"] && form["t"]["value"] === 2)return;

    _NodeList_prototype_ = 
         (_NodeList_prototype_ = form["t"]) && (_NodeList_prototype_ = _NodeList_prototype_.constructor) && _NodeList_prototype_.prototype
         || (_NodeList_prototype_ = NodeList) && _NodeList_prototype_.prototype
    ;

    Object.defineProperty(_NodeList_prototype_, "value", {
        get:  function() {
            if(!this[0] || !("form" in this[0]))return;

            var k = this.length
                , el
            ;

            while(el = this[--k]) {
                if (el.checked) {
                    return el.value;   
                }
            }
        },
        set: function(value) {
            if(!this[0] || !("form" in this[0]))return;

            var k = this.length
                , el
            ;

            while(el = this[--k]) {
                if (el.checked) {
                    el.value = value;
                    return el.value;   
                }
            }
        },
        configurable: true            
    });

    _NodeList_prototype_ = form = void 0;
}());