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Removing Item From the Playlist in Windows Store Apps

By Deepak Middha on Oct 12, 2012
In this app I described how to remove a song from the playlist in a Windows Store App using JavaScript.

Introduction

In this article I describe how to create a Windows Store App for removing a song from the playlist using JavaScript. This article will remove 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.

For the deletion of the item your playlist should contain a minimum of one item; for adding the item please visit the link Adding the item in 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.

removing-playlist-windows-store-apps.jpg

Write the following code in default.html:

<!DOCTYPE html>

<html>

<head>

    <meta charset="utf-8" />

    <title>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:violet">

    <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("Apps", {

        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>Remove</title>

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

</head>

<body>

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

        <p>

            This App will remove an item from an existing playlist (WPL, ZPL, M3U).

        </p>

        <button id="PickPlaylistButton">Pick playlist</button>

    </div>

    <div data-win-control="Apps.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", removeSong, false);

        }

    });

 

    function removeSong() {

        if (!Apps.ensureUnsnapped()) {

            return;

        }

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

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

        picker.fileTypeFilter.replaceAll(Apps.playlistExtensions);

 

        picker.pickSingleFileAsync()

            .then(function (file) {

                if (file) {

                    return Windows.Media.Playlists.Playlist.loadAsync(file);

                }

                return WinJS.Promise.wrapError("No file picked.");

            })

            .then(function (playlist) {

                Apps.playlist = playlist;

                Apps.playlist.files.removeAtEnd();

                return Apps.playlist.saveAsync();

            })

            .done(function (file) {

                WinJS.log && WinJS.log("Item removed from end of playlist.", "app", "status");

            }, 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.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 = Apps.appTitle;

    }

 

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

    WinJS.Namespace.define("Apps", {

        pageOutput: pageOutput

    });

 

})();

Output:

playlist-Windows-store-apps.jpg

Summary


In this app I described how to remove a song from the playlist 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.

Deepak Middha

Deepak Middha is one time Microsoft MVP(Client App Dev) , working as Sr. Software Developer with lots of hands on experience using ASP.NET 2.0/3.5, AJAX, MVC, C#,  SQL Server 2005/2008/2012, WCF, JQuery and Silverl... Read more

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