Media Playlist in Windows Store Apps

Introduction

Today we are going to learn how to create a Windows Store App for a media playlist using JavaScript. This app will create and save a playlist from a set of audio files by giving the appropriate locations.

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.

mediaplaylist-Windows-store-apps.jpg


Write the following code in default.html:

<!DOCTYPE html>

<html>

<head>

    <meta charset="utf-8" />

    <title>Media 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" style="background-color:gainsboro">

    <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 = "Playlists app";

 

    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.", "app", "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", {

        appTitle: appTitle,

        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>Create</title>

    <script src="/js/script.js"></script>

</head>

<body>

    <div data-win-control="App.pageInput">

        <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("PickAudioButton").addEventListener("click", pickAudio, false);

        }

    });

 

    function pickAudio() {

        if (!App.ensureUnsnapped()) {

            return;

        }

 

        var picker = new Windows.Storage.Pickers.FileOpenPicker();

        picker.suggestedStartLocation = Windows.Storage.Pickers.PickerLocationId.musicLibrary;

        picker.fileTypeFilter.replaceAll(App.audioExtensions);

 

        picker.pickMultipleFilesAsync()

            .done(function (files) {

                if (files.size > 0) {

                    App.playlist = new Windows.Media.Playlists.Playlist();

 

                    files.forEach(function (file) {

                        App.playlist.files.append(file);

                    });

 

                    App.playlist.saveAsAsync(Windows.Storage.KnownFolders.musicLibrary,

                                                   "app",

                                                   Windows.Storage.NameCollisionOption.replaceExisting,

                                                   Windows.Media.Playlists.PlaylistFormat.windowsMedia)

                        .done(function (file) {

                            WinJS.log && WinJS.log(file.name + " was created and saved with " + App.playlist.files.size + " files.", "app", "status");

                            App.playlist = null;

                        }, function (error) {

                            WinJS.log && WinJS.log(error, "app", "error");

                        });

                }

                else {

                    WinJS.log && WinJS.log("No files picked.", "app", "error");

                }

            }, function (error) {

                WinJS.log && WinJS.log(error, "app", "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.log = function (message, tag, type) {

        var statusDiv = document.getElementById("statusMessage");

    };

    function activated(e) {

        WinJS.Utilities.query("#featureLabel")[0].textContent = App.appTitle;

    }

 

    WinJS.Application.addEventListener("activated", activated, false);

    WinJS.Namespace.define("App", {

        pageOutput: pageOutput

    });

})(); 


Output:

playlist-in-indows-store-apps.jpg

Summary

In this app I described how to create and save a media 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.

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