Adaption of my dumpToDiskViaFileSystemAPI.js Gist to free Library data from Rhapsody

collectLibraryFromRhapsody.js

var context;
    
// Define the success callback for webkitRequestFileSystem()
function onInitFs(fs) {
    // Collect list of artists from the Rhapsody Library view. For each artist, we will request the 
    // library details and find the albums and tracks from each. This requires an xhr foreach
    // and to easy the load and appear less bot like, perform requests in sequence at 
    // random intervals
    context = {
        remaining: $('#library-artist-list li').toArray(), // (Sanity Check first 5) .slice(0, 5),
        chromeFS: fs,
        artists: []
    };

    // Begin processing the list
    processArtists();
}

function getRandomInt(min, max) {
    return Math.floor(Math.random() * (max - min + 1)) + min;
}

// Pop one artist from the list, perform the xhr to gather library info, persist the results and
// queue the next request to processArtists
function processArtists() {

    // Stop processing when empty
    if (context.remaining.length <= 0) return;

    // Pop the next artist to be processed and wrap with jQuery
    var $artistInfoLI = $(context.remaining.pop()),
        artist = {
            name: $artistInfoLI.text().trim(),
            albums: []
        },
        // Build url for library tracks for the artist
        artistTracksUrl = 'http://www.rhapsody.com/members/071tm1/library/artists/' + $artistInfoLI.attr('artist_id') + '/albums?me=true&l=en';

    context.artists.push(artist);
    console.log('Processing ' + artist.name + ' with ' + context.remaining.length + ' remaining');

    // Now execute the xhr to collect the tracks list for the given artist and finally save the results to disk
    $.ajax({
        url: artistTracksUrl,
        dataType: 'html',
        success: function (resultsDom) {
            // Grab each album list from the artist results page
            $(resultsDom).find('.library-tracks').each(function () {

                var $album = $(this),
                    $parent = $album.parent();

                var album = {
                    name: $parent.attr('album_name'),
                    artist: $parent.attr('artist_name'),
                    albumUrl: $parent.attr('href'),
                    tracks: []
                };

                // Add each track to the album
                $album.find('li').each(function () {

                    var $li = $(this);

                    album.tracks.push({
                        name: $li.attr('track_name'),
                        trackUrl: $li.attr('href'),
                        id: $li.attr('track_id')
                    });
                });

                // Add Album to artist
                artist.albums.push(album);
            });
        }
    });

    if (context.remaining.length > 0) {
        // Random delay recursive call
        window.setTimeout(processArtists, getRandomInt(5000, 12000));
    } else {
        saveResults();
    }
}

function saveResults() {
    // Begin the persist operation
    context.chromeFS.root.getFile('RhapsodyLibrary', { create: true }, function (fileEntry) {

        // Create a FileWriter object for our FileEntry
        fileEntry.createWriter(function (fileWriter) {

            fileWriter.onwriteend = function (e) {
                console.log('Write completed.');
                alert('Library Processing Complete');
            };

            fileWriter.onerror = function (e) {
                console.log('Write failed: ' + e.toString());
            };

            // Create a new Blob and write to the output stream/FileWriter
            fileWriter.write(new Blob([JSON.stringify(context.artists)], { type: "text/plain" }));

        }, errorHandler);

    }, errorHandler);
}

// Request persistent storage and when allowed, call into webkitRequestFileSystem and thus onInitFS
window.webkitStorageInfo.requestQuota(PERSISTENT, 1024 * 1024, function (grantedBytes) {
    window.webkitRequestFileSystem(PERSISTENT, grantedBytes, onInitFs, errorHandler);
}, errorHandler);

function errorHandler(e) {
    var msg = '';

    switch (e.code) {
        case FileError.QUOTA_EXCEEDED_ERR:
            msg = 'QUOTA_EXCEEDED_ERR';
            break;
        case FileError.NOT_FOUND_ERR:
            msg = 'NOT_FOUND_ERR';
            break;
        case FileError.SECURITY_ERR:
            msg = 'SECURITY_ERR';
            break;
        case FileError.INVALID_MODIFICATION_ERR:
            msg = 'INVALID_MODIFICATION_ERR';
            break;
        case FileError.INVALID_STATE_ERR:
            msg = 'INVALID_STATE_ERR';
            break;
        default:
            msg = 'Unknown Error';
            break;
    };

    console.log('Error: ' + msg);
}