YouTube APIを使って視聴数ランキングを表示する(PHP)

<?php
// =============================
// 設定
// =============================
$DEVELOPER_KEY = getenv('YOUTUBE_API_KEY'); // 環境変数から取得を推奨
$CHANNEL_ID = 'UCxxxxxxxxxxxxxxxxxxxxxxx'; // 対象チャンネルID
$MAX_RESULTS = 5; // 取得件数（最大50）
$MONTHS_AGO = 3; // 何ヶ月前まで遡るか
// 期間の起点日時をISO 8601形式で生成
$PERIOD = date('Y-m-d', strtotime("-{$MONTHS_AGO} month")) . 'T00:00:00Z';
// =============================
// APIリクエスト
// =============================
$params = [ 'type' => 'video', 'part' => 'snippet', 'maxResults' => $MAX_RESULTS, 'regionCode' => 'JP', 'channelId' => $CHANNEL_ID, 'order' => 'viewCount', // 視聴数順（他: date / rating / relevance） 'publishedAfter'=> $PERIOD, 'key' => $DEVELOPER_KEY,
];
$url = 'https://www.googleapis.com/youtube/v3/search?' . http_build_query($params);
$result = file_get_contents($url);
if ($result === false) { die('APIリクエストに失敗しました。');
}
$result = json_decode($result, true);
if (isset($result['error'])) { die('APIエラー: ' . $result['error']['message']);
}
// =============================
// データ整形
// =============================
$rankingList = [];
foreach ($result['items'] as $item) { $rankingList[] = [ 'videoId' => $item['id']['videoId'], 'title' => $item['snippet']['title'], 'description' => $item['snippet']['description'], 'thumbnail_medium' => $item['snippet']['thumbnails']['medium']['url'], 'publishedAt' => $item['snippet']['publishedAt'], 'channelTitle' => $item['snippet']['channelTitle'], ];
}

// =============================
// 出力
// =============================
?><ol class="ranking-list"><?php foreach ($rankingList as $rank => $video): ?> <li class="ranking-item"> <span class="rank-number"><?= $rank + 1 ?></span> <a href="https://www.youtube.com/watch?v=<?= htmlspecialchars($video['videoId']) ?>" target="_blank"> <img src="<?= htmlspecialchars($video['thumbnail_medium']) ?>" alt="<?= htmlspecialchars($video['title']) ?>"> <div class="video-info"> <h3><?= htmlspecialchars($video['title']) ?></h3> <p class="published"><?= date('Y年m月d日', strtotime($video['publishedAt'])) ?></p> <p class="description"><?= htmlspecialchars(mb_substr($video['description'], 0, 80)) ?>...</p> </div> </a> </li><?php endforeach; ?></ol>

// videoIdをカンマ区切りで結合
$videoIds = implode(',', array_column($rankingList, 'videoId'));
$statsParams = [ 'part' => 'statistics', 'id' => $videoIds, 'key' => $DEVELOPER_KEY,
];
$statsUrl = 'https://www.googleapis.com/youtube/v3/videos?' . http_build_query($statsParams);
$statsResult = json_decode(file_get_contents($statsUrl), true);
// rankingListに視聴数をマージ
$statsMap = [];
foreach ($statsResult['items'] as $item) { $statsMap[$item['id']] = $item['statistics']['viewCount'];
}
foreach ($rankingList as &$video) { $video['viewCount'] = $statsMap[$video['videoId']] ?? 0;
}
unset($video);

$cacheFile = __DIR__ . '/cache/youtube_ranking.json';
$cacheExpiry = 3600; // 1時間キャッシュ
if (file_exists($cacheFile) && (time() - filemtime($cacheFile) < $cacheExpiry)) { // キャッシュから読み込み $rankingList = json_decode(file_get_contents($cacheFile), true);
} else { // APIから取得（上記コード） // ... // キャッシュに保存 file_put_contents($cacheFile, json_encode($rankingList));
}