Cordova（Monaca）でURLから画像をダウンロードして写真ギャラリーに保存する

var downloadAndSaveImageToGallery = function(url, name){
    var fileTransfer = new FileTransfer();

    if(monaca.isIOS === true){
        var storeDirectory = cordova.file.syncedDataDirectory;
    }else{
        var storeDirectory = cordova.file.externalApplicationStorageDirectory;
    }

    var onSaveImageSuccess = function() {
        console.log('save image success');
    };

    var onSaveImageError = function (error) {
        console.log('save image error: ' + error);
    };

    fileTransfer.download(
        url,
        storeDirectory + name,
        function(entry){
            cordova.plugins.imagesaver.saveImageToGallery(
                entry.toURL(), onSaveImageSuccess, onSaveImageError);
        },
        function(error){
            console.log( "download error source" + error.source);
            console.log( "download error target" + error.target);
            console.log("download error code" + error.code);
        },
        false,
        {
            //headers: {
            //    "Authorization": "Basic dGVzdHVzZXJuYW1lOnRlc3RwYXNzd29yZA=="
            //}
        }
    );
};

document.addEventListener('deviceready', function() {
    var url = 'https://cordova.apache.org/static/img/cordova_bot.png';
    downloadAndSaveImageToGallery(url, 'cordova.png');
}, false);