Shuffle播放列表修复Youtube API

Question

所以当我试图在我的网站上创建一个嵌入式播放列表，并让它随机播放时，我发现YouTube API中有一个没有修复的错误，并且不会让任何人使用随机播放功能。

所以我试着创造一个工作。我想我可以用一个随机数代替播放列表的索引号。只要我手动输入随机数生成器的最大值和最小值，我就可以对播放列表进行洗牌。点击这里查看:http://jsfiddle.net/9kFyx/33/

虽然我对此非常满意，但我宁愿有一个更动态的代码，它只会得到播放列表数组中的元素数量，并将它们用作随机因子的最大值。听起来够简单吗?我在这里查找了API参考:https://developers.google.com/youtube/js_api_reference Retrieving_playlist_information

，发现player.getPlaylist()

我使用array.length;获取数字数组元素，并将其注入随机生成器。但是行不通!我不知道为什么。当我试图写入数组时，返回为未定义。

你能帮忙吗?

http://jsfiddle.net/42S5N/

<div id="player"></div>
<div id="output" style="width:300px; height:20px; background:white; color:black;">maxNumber</div>
<script>
    var tag = document.createElement('script');
    tag.src = "https://www.youtube.com/iframe_api";
    var firstScriptTag = document.getElementsByTagName('script')[0];
    firstScriptTag.parentNode.insertBefore(tag, firstScriptTag);
    var player;
    function onYouTubeIframeAPIReady() {
        player = new YT.Player('player', {
            height: '411',
            width: '548',
            events: {
                'onReady': onPlayerReady,
                    'onStateChange': onPlayerStateChange
            }
        });
    }

    var playlistArray;
    var playListArrayLength;
    var maxNumber;
    function onPlayerReady(event) {
        player.loadPlaylist({
            'listType': 'playlist',
                'list': 'PLhaqVbVcY6UPkbjbeJM2CwRedCrr0rPJr'
        });
        playlistArray = player.getPlaylist();
        playListArrayLength = playlistArray.length;
        maxNumber = playListArrayLength;
        document.getElementById('output').innerHTML = playListArrayLength;
        next();
    }

    function next() {
        player.loadPlaylist({
            'listType': 'playlist',
                'list': 'PLhaqVbVcY6UPkbjbeJM2CwRedCrr0rPJr',
                'index': newRandomNumber(),
                'startSeconds': '0',
                'suggestedQuality': 'small'
        });
        player.setShuffle({
            'shufflePlaylist': 'true'
        });
    }

    var oldNumber = 0;
    var NewNumber = 0;
    function newRandomNumber() {
        oldNumber = NewNumber;
        NewNumber = Math.floor(Math.random() * maxNumber);
        if (NewNumber == oldNumber) {
            newRandomNumber();
        } else {
            return NewNumber;
        }
    }
    function onPlayerStateChange(event) {
        if (event.data == YT.PlayerState.ENDED) {
            next();
        }
    }
</script>

Answer 1

调用player.loadPlaylist()和能够获得player.getPlaylist()的播放列表之间有延迟。这个答案通过等待CUED事件提供了一个修复，但在我的测试中，它根本没有被触发，所以我检查了PLAYING事件，它工作得很好。

你的代码应该是这样的:

function onPlayerReady(event) {
    player.loadPlaylist({
        'listType': 'playlist',
        'list': 'PLhaqVbVcY6UPkbjbeJM2CwRedCrr0rPJr'
    });
}
var firstLoad = true;
function onPlayerStateChange(event) {
    if (event.data == YT.PlayerState.ENDED) {
        next();
    } else {
        if (firstLoad && event.data == YT.PlayerState.PLAYING) {
            firstLoad = false;
            playlistArray = player.getPlaylist();
            playListArrayLength = playlistArray.length;
            maxNumber = playListArrayLength;
            document.getElementById('output').innerHTML = playListArrayLength;
            next();
        }
    }
}

Answer 2

我在PHP中的解决方案，有点压倒性，但它工作。

function getNumberofElements() {
    $pid = $this->getPID();
    $url = "https://www.googleapis.com/youtube/v3/playlists?part=contentDetails&id=$pid&key=$yourAPIKey";
    $ch = curl_init($url);
    curl_setopt($ch, CURLOPT_HTTPGET, TRUE);
    curl_setopt($ch, CURLOPT_POST, FALSE);
    curl_setopt($ch, CURLOPT_HEADER, false);
    curl_setopt($ch, CURLOPT_NOBODY, FALSE);
    curl_setopt($ch, CURLOPT_VERBOSE, FALSE);
    curl_setopt($ch, CURLOPT_REFERER, "");
    curl_setopt($ch, CURLOPT_FOLLOWLOCATION, TRUE);
    curl_setopt($ch, CURLOPT_MAXREDIRS, 4);
    curl_setopt($ch, CURLOPT_RETURNTRANSFER, TRUE);
    curl_setopt($ch, CURLOPT_USERAGENT, "Mozilla/5.0 (Windows; U; Windows NT 6.1; he; rv:1.9.2.8) Gecko/20100722 Firefox/3.6.8");
    $numberOfElements = curl_exec($ch);  // $xml = simplexml_load_string($numberOfElements);
    $numberOfElements = substr(strstr($numberOfElements, 'itemCount":'), strlen('itemCount":'));
    $numberOfElements = str_replace("}", " ", $numberOfElements);
    $numberOfElements = str_replace("]", " ", $numberOfElements);
    return $numberOfElements;
}