ListDataSource in Windows Store App

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.

Write the following code in the default.html:

<!DOCTYPE html>

<html>

<head>

</head>

</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>

</head>

<body>

<div>

Shuffle Nomber

</button>

Add a random Nomber

</button>

</div>

</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:

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.