Angular: Empty Fiddle

http://angularjs.org/

HTML

<script src="http://code.angularjs.org/angular-1.0.1.js"></script>
<div ng-controller="MyCtrl">
    <ul>
       <li class="week-row" ng-repeat="week in weeks" id="{{$index}}">
            <ul class="tiles" ng-class="{'expanded' : week.isOpen, 'hidden' : !week.isOpen}">
                <li ng-repeat="day in week.days" ng-class="{'active': (activeDay == $parent.$index + '-' + $index) }" class="day-title" id="{{$parent.$index + '-' + $index}}" ng-click="fn2({ week: $parent.$index, day: $index })">{{day}}</li>
            </ul>
        </li>
    </ul>
</div>

CSS

.day-title {
    color:blue;
    cursor:pointer;
}
.active {
    color:green;
}
.expanded {
    border: 1px solid black;
}
.hidden {
    display:none;
}

JavaScript

var myApp = angular.module('myApp',[]);

//myApp.directive('myDirective', function() {});
//myApp.factory('myService', function() {});

function MyCtrl($scope) {
    $scope.activeDay = null;

    $scope.fn2 = function (data) {
        $scope.activeDay = data.week + '-' + data.day;
    };

    $scope.weeks = [{
        isOpen : true,
        days: ['mon', 'tue', 'wed']
    }];
    
}