AngularJS Example:

HTML

<link rel="stylesheet" href="http://twitter.github.com/bootstrap/assets/css/bootstrap.css">
<div ng-app ng-controller="TodoCtrl">
 <li ng-class="getClass(key)" ng-repeat="(key, data) in bigData" ng-click="activate(key)">
lol
</li>
</div>

JavaScript

function TodoCtrl($scope) {
    $scope.bigData = {
        key1 : {label:"v1"},
        key2 : {label:"v2"},
        key3 : {label:"v3"},
        
    }
    
    $scope.activeClass = function(v){
        return(v);
    }
    
    $scope.activate = function(v){
        alert(v);
    }
 }