PhoneJS 14.1 DataSource filter

HTML

<script src="http://cdnjs.cloudflare.com/ajax/libs/knockout/3.1.0/knockout-min.js"></script>
<script src="http://ajax.aspnetcdn.com/ajax/globalize/0.1.1/globalize.min.js"></script>
<link rel="stylesheet" href="http://cdn3.devexpress.com/jslib/14.1.6/css/dx.ios7.default.css">
<script src="http://cdn3.devexpress.com/jslib/14.1.6/js/dx.phonejs.js"></script>
<link rel="stylesheet" href="http://cdn3.devexpress.com/jslib/14.1.6/css/dx.common.css">
<div data-bind="dxList: { dataSource: dataSource }">
    <div data-options="dxTemplate: { name: 'item' }">
        <div data-bind="text: City"></div>
    </div>
</div>

CSS

.dx-list {
    height: 200px;
}

JavaScript

var cities = [
    { City: "London" },
    { City: "London" },
    { City: "Moscow" },
    { City: "Paris" }
];

var vm = {
    
    dataSource: new DevExpress.data.DataSource({
        store: cities,
        filter: ["City", "London"]
        map: function (item) 
            return item;
        }
    })
}

ko.applyBindings(vm);{
            return item;
        }
    })
}

ko.applyBindings(vm);