StringUtil.php

<?php
/**
 * (c) Artem Ostretsov <artem@ostretsov.ru>
 * Created at 25.01.2016 11:22
 */

namespace SP\MainBundle\Util;


class StringUtil
{
    /**
     * @param string $text
     * @param array $availableHtmlTags
     * @param array $availableAttributes
     * @return string
     */
    public static function stripTagsAndAttrs($text, array $availableHtmlTags, array $availableAttributes = ['href', 'src', 'style'])
    {
        $availableHtmlTags = '<'.implode('><', $availableHtmlTags).'>';
        $text = strip_tags($text, $availableHtmlTags);
        $result = preg_replace_callback(
            '/<([a-zA-Z]+.*?)>/ui',
            function ($matches) use ($availableAttributes) {
                $tagParts = $matches[1];
                $trailing = '';
                if (mb_substr($matches[1], -1) == '/') {
                    $tagParts = mb_substr($matches[1], 0, -1);
                    $trailing = '/';
                }

                $tagParts = preg_replace_callback(
                    '/[\'\"](.*?)[\'\"]/',
                    function ($matches) {
                        return str_replace(' ', '#&#&#', $matches[0]);
                    },
                    $tagParts
                );

                $tagParts = array_map(
                    'trim',
                    explode(' ', str_replace('=', ' = ', $tagParts))
                );
                $tag = array_shift($tagParts);
                $tagParts = array_filter(
                    $tagParts,
                    function ($e) {
                        return !empty($e);
                    }
                );

                // get all attributes and their values
                $tagParts = array_values($tagParts);
                $attrs = [];
                while (count($tagParts) > 0) {
                    foreach ($tagParts as $position => $token) {
                        if ($token == '=') {
                            if (isset($tagParts[$position - 1]) && isset($tagParts[$position + 1])) {
                                $attrs[$tagParts[$position - 1]] = $tagParts[$position + 1];
                            }

                            unset ($tagParts[$position]);

                            if (isset($tagParts[$position - 1])) {
                                unset ($tagParts[$position - 1]);
                            }

                            if (isset($tagParts[$position + 1])) {
                                unset ($tagParts[$position + 1]);
                            }

                            continue 2;
                        } else {
                            continue;
                        }
                    }

                    break;
                }

                foreach ($tagParts as $token) {
                    $attrs[$token] = null;
                }

                foreach ($attrs as $key => $value) {
                    if (!in_array($key, $availableAttributes)) {
                        unset($attrs[$key]);
                    }
                }

                $result[] = $tag;
                foreach ($attrs as $key => $value) {
                    $attr = !empty($value) ? $key.'='.$value : $key;
                    $result[] = str_replace('#&#&#', ' ', $attr);
                }

                return '<'.implode(' ', $result).$trailing.'>';
            },
            $text
        );

        return $result;
    }
}