ShortcodeService.php

<?php
namespace App\Service;

final class ShortcodeService {
    private $shortcodes = [];
    
    public function isShortcode($name) {
        return isset($this->shortcodes[$name]);
    }

    /**
    * Returns all the attrs of a found shortcode as a key / value array.
    *
    * @param string $text
    * @return array
    */
    private function _shortcodeParseAttrs(string $text): array {
        $attrs = []
        $pattern = '/(\w+)\s*=\s*"([^"]*)"(?:\s|$)|(\w+)\s*=\s*\'([^\']*)\'(?:\s|$)|(\w+)\s*=\s*([^\s\'"]+)(?:\s|$)|"([^"]*)"(?:\s|$)|(\S+)(?:\s|$)/';
        $text = preg_replace("/[\x{00a0}\x{200b}]+/u", " ", $text);
        $text = html_entity_decode($text);
        if (preg_match_all($pattern, $text, $match, PREG_SET_ORDER)) {
            foreach ($match as $m) {
            if (!empty($m[1])) {
                $attrs[strtolower($m[1])] = stripcslashes($m[2]);
            }
            elseif (!empty($m[3])) {
                $attrs[strtolower($m[3])] = stripcslashes($m[4]);
            }
            elseif (!empty($m[5])) {
                $attrs[strtolower($m[5])] = stripcslashes($m[6]);
            }
            elseif (isset($m[7]) and strlen($m[7])) {
                $attrs[] = stripcslashes($m[7]);
            }
            elseif (isset($m[8])) {
                $attrs[] = stripcslashes($m[8]);
            }
            }
        }
        else {
            $attrs = ltrim($text);
        }
        return $attrs;
    }
  
    /**
    * Process one shortcode
    *
    * @param array $m contains the match of the regex
    * @return string
    *
    */
    private function _shortcodeProcessTag(array $m): string {
        $shortcodes = $this->shortcodes;
        $tag = $m[2];
        if (!empty($shortcodes[$tag])) {
            $attr = $this->_shortcodeParseAttrs($m[3]);
            $shortcode = $shortcodes[$tag];
            if (!empty($m[4])) {
                return $m[1] . $shortcode->apply($attr, $m[4]) . $m[5];
            } else {
                return $m[1] . $shortcode->apply($attr, null). $m[5];
            }
        } elseif (empty($m[4])) {
            return $m[4];
        }
        return '';
    }
  
    /**
    * Process a text with shortcodes
    */
    public function shortcodeProcess(string $text) {
        $shortcodes = $this->shortcodes;
        $chunks = preg_split('!(\[{1,2}.*?\]{1,2})!', $text, -1, PREG_SPLIT_DELIM_CAPTURE);
        $heap = array();
        $heapIndex = array();
        foreach ($chunks as $c) {
            if (!$c) {
                continue;
            }
            $escaped = false;
            if ((substr($c, 0, 2) == '[[') && (substr($c, -2, 2) == ']]')) {
                $escaped = true;
                if ((substr($c, 0, 3) != '{') && (substr($c, -3, 1) != '}')) {
                    $c = substr($c, 1, -1);
                }
            }
            if (!$escaped && ($c[0] == '[') && (substr($c, -1, 1) == ']')) {
                $originalText = $c;
                $c = substr($c, 1, -1);
                $c = trim($c);
                $ts = explode(' ', $c);
                $tag = array_shift($ts);
                $tag = trim($tag, '/');
                if (!$this->isShortcode($tag)) {
                    array_unshift($heapIndex, '_string_');
                    array_unshift($heap, $originalText);
                }   elseif (substr($c, -1, 1) == '/') {
                    $m = array(
                        $c,
                        '',
                        $tag,
                        implode(' ', $ts),
                        NULL,
                        '',
                    );
                    array_unshift($heap_index, '_string_');
                    array_unshift($heap, $this->_shortcodeProcessTag($m));
                } elseif ($c[0] == '/') {
                    $closingTag = substr($c, 1);
                    $processHeap = array();
                    $processHeapIndex = array();
                    $found = FALSE;
                    do {
                        $tag = array_shift($heapIndex);
                        $heapText = array_shift($heap);
                        if ($closingTag == $tag) {
                            $m = array(
                                $tag . ' ' . $heapText,
                                '',
                                $tag,
                                $heapText,
                                implode('', $processHeap),
                                '',
                            );
                            $str = $this->_shortcodeProcessTag($m);
                            array_unshift($heapIndex, '_string_');
                            array_unshift($heap, $str);
                            $found = TRUE;
                        } else {
                            array_unshift($processHeap, $heapText);
                            array_unshift($processHeapIndex, $tag);
                        }
                    } while (!$found && $heap);
                    if (!$found) {
                        foreach ($processHeap as $val) {
                            array_unshift($heap, $val);
                        }
                        foreach ($processHeapIndex as $val) {
                            array_unshift($heapIndex, $val);
                        }
                    }
                } else {
                    array_unshift($heapIndex, $tag);
                    array_unshift($heap, implode(' ', $ts));
                }
            } else {
                array_unshift($heapIndex, '_string_');
                array_unshift($heap, $c);
            }
        }
        return (implode('', array_reverse($heap)));
    }
}