Removing Item From the Playlist in Windows Store Apps

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.

Write the following code in default.html:

<!DOCTYPE html>

<html>

<head>

</head>

</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>

<head>

<title>Remove</title>

</head>

<body>

<p>

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

</p>

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

</div>

</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:

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.