PHPのAPPで絵文字式パックを処理する方法

<?php 
class Emoji
{
    /**
     * 将表情转成对应代表字符串
     * @param string $content
     */
    public static function emojiEncode($content = &#39;&#39;)
    {
        if (!$content) {
            return $content;
        }
        $content = json_encode($content);

        $emoji = requrie_once(&#39;emoji.php&#39;);
        $content = str_replace(array_keys($emoji[&#39;regenEncode&#39;]), $emoji[&#39;regenEncode&#39;], $content);
        $content = json_decode($content, true);
        return $content;
    }

    /**
     * 将对应字符串转成表情
     * @param string $content
     */
    public static function emojiDecode($content = &#39;&#39;)
    {
        if (!$content) {
            return $content;
        }
        $content = json_encode($content);

        $emoji = requrie_once(&#39;emoji.php&#39;);
        $content = str_replace(array_keys($emoji[&#39;regenDecode&#39;]), $emoji[&#39;regenDecode&#39;], $content);
        $content = json_decode($content, true);
        return $content;
    }
}