Introduction
In this article I describe how to create a Windows Store App using JavaScript that defines an Object. The sample app demonstates definition of a simple JavaScript object, with methods and defaults being placed on the function prototype, using the Win.Class.define method.
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 app, add two JavaScript pages 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 one HTML page to your project.
![defining-windows-store-app.jpg]()
Write the following code in 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="/app-utils/app-utils.css" />
<link rel="stylesheet" href="/css/default.css" />
<script src="/js/default.js"></script>
</head>
<body role="application" style="background-color: lightcyan">
<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 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).then(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 page.html:
<!DOCTYPE html>
<html>
<head>
<title></title>
<script src="/js/script.js"></script>
</head>
<body>
<div data-win-control="app.pageInput">
<button class="action winClassDefineCreateInstance">Create Instance of Defined Class</button>
<button class="action secondary winClassDefineCreateAndSetProperties">Create Instance and set properties</button>
<br />
<br />
</div>
<div data-win-control="app.pageOutput">
<div class="winClassDefineOutputTable">
<table>
<thead>
<tr>
<th>Member</th>
<th>Value</th>
<th>From Prototype?</th>
</tr>
</thead>
<tbody>
<tr class="winClassDefineX">
<td>X</td>
<td></td>
<td></td>
</tr>
<tr class="winClassDefineY">
<td>Y</td>
<td></td>
<td></td>
</tr>
<tr class="winClassDefineWidth">
<td>Width</td>
<td></td>
<td></td>
</tr>
<tr class="winClassDefineHeight">
<td>Height</td>
<td></td>
<td></td>
</tr>
<tr class="winClassDefineArea">
<td>Area</td>
<td></td>
<td></td>
</tr>
<tr class="winClassDefineToString">
<td>ToString</td>
<td></td>
<td></td>
</tr>
</tbody>
</table>
</div>
</div>
</body>
</html>
Write the following code in script.js:
(function () {
"use strict";
var Rect = WinJS.Class.define(
function () { },
{
x: 0,
y: 0,
width: 0,
height: 0,
area: function () { return this.width * this.height; },
toString: function () {
return "rectangle (" +
[this.x, this.y, this.width, this.height].join(", ") +
")";
}
}
);
function defaultRect() {
WinJS.log && WinJS.log("Default state of new Rect object", "app", "status");
return new Rect();
}
function rectWithPropertyChanges() {
WinJS.log && WinJS.log("Status of rect after properties get set", "app", "status");
var r = new Rect();
r.width = 5;
r.height = 4;
return r;
}
var page = WinJS.UI.Pages.define("page.html", {
ready: function (element, options) {
var root = new WinJS.Utilities.QueryCollection(element);
this.outputTable = root.query(".winClassDefineOutputTable");
this.hideOutputTable();
root.query(".winClassDefineCreateInstance").listen("click", this.showDefaultRect.bind(this));
root.query(".winClassDefineCreateAndSetProperties").listen("click", this.showRectWithPropertyChanges.bind(this));
},
hideOutputTable: function () {
this.outputTable.setStyle("visibility", "hidden");
},
showOutputTable: function () {
this.outputTable.setStyle("visibility", "visible");
},
showDefaultRect: function () {
this.showOutputTable();
this.displayRect(defaultRect());
},
showRectWithPropertyChanges: function () {
this.showOutputTable();
this.displayRect(rectWithPropertyChanges());
},
displayRect: function (rect) {
this.updateRow("X", rect.x, rect.hasOwnProperty("x"));
this.updateRow("Y", rect.y, rect.hasOwnProperty("y"));
this.updateRow("Width", rect.width, rect.hasOwnProperty("width"));
this.updateRow("Height", rect.height, rect.hasOwnProperty("height"));
this.updateRow("Area", rect.area(), rect.hasOwnProperty("area"));
this.updateRow("ToString", rect.toString(), rect.hasOwnProperty("toString"));
},
updateRow: function (rowIdSuffix, propertyValue, isOwnProperty) {
var tr = this.outputTable.query(".winClassDefine" + rowIdSuffix)[0];
tr.cells[1].innerText = propertyValue;
tr.cells[2].innerText = isOwnProperty ? "no" : "yes";
}
});
})();
Output:
![defining-object-in-windows-store-apps.jpg]()
Summary
In this app I described how to define a simple Object in a Windows Store App using JavaScript. I hope this article has helped you to understand this topic. Please share if you know more about this. Your feedback and constructive contributions are welcome.