vendor/ezyang/htmlpurifier/library/HTMLPurifier/AttrDef/Lang.php

这里只显示每个文件的开头 60 行。登录后可以解锁完整代码。

微信扫码关注公众号，代码整理好后第一时间通知你。

<?php

/**
 * Validates the HTML attribute lang, effectively a language code.
 * @note Built according to RFC 3066, which obsoleted RFC 1766
 */
class HTMLPurifier_AttrDef_Lang extends HTMLPurifier_AttrDef
{

    /**
     * @param string $string
     * @param HTMLPurifier_Config $config
     * @param HTMLPurifier_Context $context
     * @return bool|string
     */
    public function validate($string, $config, $context)
    {
        $string = trim($string);
        if (!$string) {
            return false;
        }

        $subtags = explode('-', $string);
        $num_subtags = count($subtags);

        if ($num_subtags == 0) { // sanity check
            return false;
        }

        // process primary subtag : $subtags[0]
        $length = strlen($subtags[0]);
        switch ($length) {
            case 0:
                return false;
            case 1:
                if (!($subtags[0] == 'x' || $subtags[0] == 'i')) {
                    return false;
                }
                break;
            case 2:
            case 3:
                if (!ctype_alpha($subtags[0])) {
                    return false;
                } elseif (!ctype_lower($subtags[0])) {
                    $subtags[0] = strtolower($subtags[0]);
                }
                break;
            default:
                return false;
        }

        $new_string = $subtags[0];
        if ($num_subtags == 1) {
            return $new_string;
        }

        // process second subtag : $subtags[1]
        $length = strlen($subtags[1]);
        if ($length == 0 || ($length == 1 && $subtags[1] != 'x') || $length > 8 || !ctype_alnum($subtags[1])) {
            return $new_string;