Introduction
Today we are going to learn how to create a Windows Store App for adding a song to the playlist using JavaScript. This article will add items to the end of an existing playlist (WPL, ZPL, M3U). In the previous article I described how to create and save the media Playlist in Windows Store Apps You can visit it at Media Playlist In Windows Store Apps using JavaScript.
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 give an appropriate name. In the same way, add one HTML page to your project.
![playlist-windows-store-Apps.jpg]()
Write the following code in default.html:
<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8" />
<title>My App</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/script1.js"></script>
<script src="/js/default.js"></script>
</head>
<body role="application">
<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 exTitle = "";
var Pages = [
{ url: "page.html" }
];
var audioExtensions = [".wma", ".mp3", ".mp2", ".aac", ".adt", ".adts", ".m4a"];
var playlistExtensions = [".m3u", ".wpl", ".zpl"];
var playlist = null;
var ensureUnsnapped = function () {
var success = true;
if (Windows.UI.ViewManagement.ApplicationView.value === Windows.UI.ViewManagement.ApplicationViewState.snapped) {
success = Windows.UI.ViewManagement.ApplicationView.tryUnsnap();
}
if (!success) {
WinJS.log && WinJS.log("Unable to unsnap the app.", "ex", "error");
}
return success;
};
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", {
exTitle: exTitle,
Pages: Pages,
audioExtensions: audioExtensions,
playlistExtensions: playlistExtensions,
playlist: playlist,
ensureUnsnapped: ensureUnsnapped
});
WinJS.Application.addEventListener("activated", activated, false);
WinJS.Application.start();
})();
Write the following code in page.html:
<!DOCTYPE html>
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<title>Add</title>
<script src="/js/script.js"></script>
</head>
<body>
<div data-win-control="App.PageInput">
<button id="PickPlaylistButton">Pick playlist</button>
<button id="PickAudioButton">Pick audio</button>
</div>
<div data-win-control="App.PageOutput">
</div>
</body>
</html>
Write the following code in script.js:
(function () {
"use strict";
var page = WinJS.UI.Pages.define("page.html", {
ready: function (element, options) {
document.getElementById("PickPlaylistButton").addEventListener("click", loadPlaylist, false);
document.getElementById("PickAudioButton").addEventListener("click", addSong, false);
}
});
function loadPlaylist() {
if (!App.ensureUnsnapped()) {
return;
}
var picker = new Windows.Storage.Pickers.FileOpenPicker();
picker.suggestedStartLocation = Windows.Storage.Pickers.PickerLocationId.musicLibrary;
picker.fileTypeFilter.replaceAll(App.playlistExtensions);
picker.pickSingleFileAsync()
.then(function (file) {
if (file) {
return Windows.Media.Playlists.Playlist.loadAsync(file);
}
return WinJS.Promise.wrapError("No file picked");
}, function (error) {
WinJS.log && WinJS.log("Error in picking file.", "ex", "error");
})
.done(function (playlist) {
App.playlist = playlist;
WinJS.log && WinJS.log("Playlist loaded.", "ex", "status");
}, function (error) {
WinJS.log && WinJS.log(error, "ex", "error");
});
}
function addSong() {
if (App.playlist) {
if (!App.ensureUnsnapped()) {
return;
}
var picker = new Windows.Storage.Pickers.FileOpenPicker();
picker.suggestedStartLocation = Windows.Storage.Pickers.PickerLocationId.musicLibrary;
picker.fileTypeFilter.replaceAll(App.audioExtensions);
var numFilesPicked = 0;
picker.pickMultipleFilesAsync()
.then(function (files) {
if (files.size > 0) {
numFilesPicked = files.size;
files.forEach(function (file) {
App.playlist.files.append(file);
});
return App.playlist.saveAsync();
}
else {
return WinJS.Promise.wrapError("No files picked.");
}
})
.done(function (file) {
WinJS.log && WinJS.log(numFilesPicked + " files added to playlist.", "ex", "status");
}, function (error) {
WinJS.log && WinJS.log(error, "ex", "error");
});
}
else {
WinJS.log && WinJS.log("Pick playlist first.", "ex", "error");
}
}
})();
Write the following code in script1.js:
(function () {
var PageOutput = WinJS.Class.define(
function (element, options) {
element.winControl = this;
this.element = element;
new WinJS.Utilities.QueryCollection(element)
.setAttribute("role", "region")
.setAttribute("aria-labelledby", "outputLabel")
.setAttribute("aria-live", "assertive");
element.id = "output";
this._addOutputLabel(element);
this._addStatusOutput(element);
}, {
_addOutputLabel: function (element) {
var label = document.createElement("h2");
label.id = "outputLabel";
label.textContent = "";
element.parentNode.insertBefore(label, element);
},
_addStatusOutput: function (element) {
var statusDiv = document.createElement("div");
statusDiv.id = "statusMessage";
element.insertBefore(statusDiv, element.childNodes[0]);
}
}
);
var currentPageUrl = null;
WinJS.Navigation.addEventListener("navigating", function (evt) {
currentPageUrl = evt.detail.location;
});
WinJS.log = function (message, tag, type) {
var statusDiv = document.getElementById("statusMessage");
};
function activated(e) {
WinJS.Utilities.query("#featureLabel")[0].textContent = App.exTitle;
}
WinJS.Application.addEventListener("activated", activated, false);
WinJS.Namespace.define("App", {
PageOutput: PageOutput
});
})();
Output:
![playlist-window-store-app.jpg]()
![media-playlist-windows-store-apps.jpg]()
Summary
In this app I described how to add a song to the playlist in a Windows Store App 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.