/home/kueuepay/www/vendor/ezyang/htmlpurifier/library/HTMLPurifier/AttrDef/HTML/Nmtokens.php
<?php

/**
 * Validates contents based on NMTOKENS attribute type.
 */
class HTMLPurifier_AttrDef_HTML_Nmtokens 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);

        // early abort: '' and '0' (strings that convert to false) are invalid
        if (!$string) {
            return false;
        }

        $tokens = $this->split($string, $config, $context);
        $tokens = $this->filter($tokens, $config, $context);
        if (empty($tokens)) {
            return false;
        }
        return implode(' ', $tokens);
    }

    /**
     * Splits a space separated list of tokens into its constituent parts.
     * @param string $string
     * @param HTMLPurifier_Config $config
     * @param HTMLPurifier_Context $context
     * @return array
     */
    protected function split($string, $config, $context)
    {
        // OPTIMIZABLE!
        // do the preg_match, capture all subpatterns for reformulation

        // we don't support U+00A1 and up codepoints or
        // escaping because I don't know how to do that with regexps
        // and plus it would complicate optimization efforts (you never
        // see that anyway).
        $pattern = '/(?:(?<=\s)|\A)' . // look behind for space or string start
            '((?:--|-?[A-Za-z_])[A-Za-z_\-0-9]*)' .
            '(?:(?=\s)|\z)/'; // look ahead for space or string end
        preg_match_all($pattern, $string, $matches);
        return $matches[1];
    }

    /**
     * Template method for removing certain tokens based on arbitrary criteria.
     * @note If we wanted to be really functional, we'd do an array_filter
     *       with a callback. But... we're not.
     * @param array $tokens
     * @param HTMLPurifier_Config $config
     * @param HTMLPurifier_Context $context
     * @return array
     */
    protected function filter($tokens, $config, $context)
    {
        return $tokens;
    }
}

// vim: et sw=4 sts=4
Best Practice

Best Practices

To ensure a smooth integration process and optimal performance, follow these best practices:

  1. Use secure HTTPS connections for all API requests.
  2. Implement robust error handling to handle potential issues gracefully.
  3. Regularly update your integration to stay current with any API changes or enhancements.