Introduction
In this article I describe how to create Windows Store Apps for ListDataSource using JavaScript. This app demonstrates how to use the ListDataSource API to programmatically manipulate items in a ListView. This can be used with all datasources, unlike Binding.List which is unique to it.
I assume you can create a simple Windows Store App using JavaScript; for more help visit Simple Windows Store Apps using JavaScript. In my previous article I discribe Binding.List; see: Binding.List Windows Store App.
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.
![listdatasource_in-windows-store--app.jpg]()
Write the following code in the default.html:
<!DOCTYPE html>
<html>
<head>
<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 Nomber
</button>
<button id="addnomber" class="action secondary">
Add a random Nomber
</button>
</div>
</div>
<div data-win-control="App.pageOutput">
<div id="nomberTemplate" data-win-control="WinJS.Binding.Template">
<div class="nomberTempl">
<h6 class="counter" data-win-bind="innerText: counter"></h6>
<h1 class="letter" data-win-bind="innerText: letter"></h1>
</div>
</div>
<div id="listView3" 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", shufflenombers, false);
element.querySelector("#addnomber").addEventListener("click", addnomber, false);
initnombers();
}
});
var _tIndex = 0;
var _letterSrc = "1234567890".split("");
function initnombers() {
var letters = [];
for (var i = 0; i < 7; i++) {
letters[i] = generatenomber();
}
var lettersList = new WinJS.Binding.List(letters);
var list2 = document.getElementById("listView3").winControl;
list2.itemDataSource = lettersList.dataSource;
list2.itemTemplate = document.getElementById("nomberTemplate");
list2.forceLayout();
}
function generatenomber() {
var nomber = {
letter: _letterSrc[Math.floor(Math.random() * _letterSrc.length)],
counter: _tIndex
};
_tIndex++;
return nomber;
}
function shufflenombers() {
var ds = document.getElementById("listView3").winControl.itemDataSource;
ds.getCount().done(function (count) {
if (count > 0) {
var binding = ds.createListBinding();
var keys = [], p = [];
for (var i = 0; i < count; i++) {
(function (j) {
p[j] = binding.fromIndex(j).then(function (currentItem) {
keys[j] = currentItem.key;
});
})(i);
}
WinJS.Promise.join(p).done(function () {
binding.release();
ds.beginEdits();
for (var itemIndex = 0; itemIndex < count; itemIndex++) {
var randomIndex = Math.floor(Math.random() * (count - itemIndex));
if (randomIndex < 0 || randomIndex === keys.length) { debugger; }
var key = keys[randomIndex];
keys.splice(randomIndex, 1);
ds.moveToStart(key);
}
ds.endEdits();
});
}
});
}
function addnomber() {
var ds = document.getElementById("listView3").winControl.itemDataSource;
ds.beginEdits();
var nomber = generatenomber();
ds.insertAtEnd(null, nomber);
ds.endEdits();
}
})();
Output:
![listdatasource_in-windows-store--apps.jpg]()
Summary
In this article I described how to create a Windows Store App for ListDataSource 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.