Introduction
In this article I describe how to create a Windows Store App for Binding.List using JavaScript. Binding.List is an in-memory data source with an API like JavaScript Arrays. The App generates a set of random letters and uses a Binding.List to store them.
I assume you can create a simple Windows Store App using JavaScript; for more help visit Simple Windows Store Apps using JavaScript.
To start the creation of the apps, add one JavaScript page by right-clicking on the js folder in the Solution Explorer and select "Add" > "New item" > "JavaScript Page" and then provide an appropriate name. In the same way, add a HTML page to your project.
![binding-list_in-windows-store-app.jpg]()
Write the following code in the default.html:
<!DOCTYPE html>
<html>
<head>
    <meta charset="utf-8" />
    <title></title>
    <link rel="stylesheet" href="//Microsoft.WinJS.1.0/css/ui-light.css" />
    <script src="//Microsoft.WinJS.1.0/js/base.js"></script>
    <script src="//Microsoft.WinJS.1.0/js/ui.js"></script>
    <link rel="stylesheet" href="/css/default.css" />
    <script src="/js/default.js"></script>
</head>
<body role="application"style="background-color:lightpink">
    <center><div id="rootGrid">
        <div id="content">
            <h1 id="featureLabel"></h1>
            <div id="contentHost"></div>
        </div>
    </div></center>
</body>
</html>
Write the following code in the default.js:
(function () {
    "use strict";
    var appTitle = "";
    var pages = [
        { url: "page.html"}
    ];
    function activated(eventObject) {
        if (eventObject.detail.kind === Windows.ApplicationModel.Activation.ActivationKind.launch) {
            eventObject.setPromise(WinJS.UI.processAll().then(function () {
                var url = WinJS.Application.sessionState.lastUrl || pages[0].url;
                return WinJS.Navigation.navigate(url);
            }));
        }
    }
    WinJS.Navigation.addEventListener("navigated", function (eventObject) {
        var url = eventObject.detail.location;
        var host = document.getElementById("contentHost");
        host.winControl && host.winControl.unload && host.winControl.unload();
        WinJS.Utilities.empty(host);
        eventObject.detail.setPromise(WinJS.UI.Pages.render(url, host, eventObject.detail.state).done(function () {
            WinJS.Application.sessionState.lastUrl = url;
        }));
    });
    WinJS.Namespace.define("App", {
        appTitle: appTitle,
        pages: pages
    });
    WinJS.Application.addEventListener("activated", activated, false);
    WinJS.Application.start();
})(); 
Write the following code in the page.html:
 
<!DOCTYPE html>
<html>
<head>
    <title></title>
    <script src="/js/script.js"></script>
</head>
<body>
    <div data-win-control="App.pageInput"> 
        <div>
            <button id="shuffle" class="action secondary">
                Shuffle Letter
            </button>            
            <button id="addlatter" class="action secondary">
                Add letter
            </button>
        </div>
    </div>
    <div data-win-control="App.pageOutput">
        <div id="latterTemplate" data-win-control="WinJS.Binding.Template">
            <div class="latterTempl">
                <h6 class="counter" data-win-bind="innerText: counter"></h6>
                <h1 class="letter" data-win-bind="innerText: letter"></h1>
            </div>
        </div>
        <div id="listView2" class="box win-selectionstylefilled" data-win-control="WinJS.UI.ListView" data-win-options="{ selectionMode: 'multi', reorderable: true,  layout: { type: WinJS.UI.GridLayout, maxRows: 1 } }">
        </div>
    </div>
</body>
</html> 
Write the following code in the script.js:
(function () {
    "use strict";
    var page = WinJS.UI.Pages.define("page.html", {
        ready: function (element, options) {
            element.querySelector("#shuffle").addEventListener("click", shufflelatters, false);
            element.querySelector("#addlatter").addEventListener("click", addlatter, false);
            initlatters();
        }
    });
    var _tIndex = 0;
    var _letterSrc = "ABCDEFGHIJKLMNOPQRSTUVWXYZ".split("");
    var lettersList = {};
    function initlatters() {
        var letters = [];
        for (var i = 0; i < 7; i++) {
            letters[i] = generatelatter();
        }
        lettersList = new WinJS.Binding.List(letters);
        var list2 = document.getElementById("listView2").winControl;
        list2.itemDataSource = lettersList.dataSource;
        list2.itemTemplate = document.getElementById("latterTemplate");
        list2.forceLayout();
    }
    function generatelatter() {
        var latter = {
            letter: _letterSrc[Math.floor(Math.random() * _letterSrc.length)],
            counter: _tIndex
        };
        _tIndex++;
 
        return latter;
    }
    function shufflelatters() {
        var count = lettersList.length;
        if (count > 0) {
            for (var itemIndex = 0; itemIndex < count; itemIndex++) {
                var randomIndex = Math.floor(Math.random() * (count - itemIndex));
                lettersList.move(randomIndex, 0);
            }
        }
    }
    function addlatter() {
        var latter = generatelatter();
        lettersList.push(latter);
    }
})(); 
Output:
![binding-list_in-windows-store--app.jpg]()
Summary
In this article I described how to create a Windows Store App for Binding.List using JavaScript. I hope this article has helped you to understand this topic. Please share it. If you know more about this, your feedback and constructive contributions are welcome.