toc = []; * } * ``` * * Make sure to add the TOC on postprocess(): * * ```php * protected function prepare() * { * return parent::postprocess( * $this->addToc($markup) * ); * } * ``` */ trait TocTrait { /** * @var mixed[] - Headings detected and rendered in the text. */ protected $toc = []; /** * Identify a line as a TOC. */ protected function identifyToc($line, $lines, $current): bool { return preg_match('/^ {0,3}(\[(\[_)?TOC(_\])?\])([ \t]|$)/', $line); } /** * Consume lines for a TOC. */ protected function consumeToc($lines, $current): array { return [['toc'], $current]; } /** * Renders a TOC. */ protected function renderToc($block): string { $objChr = "\u{FFFC}"; // Render a placeholder to be populated // using the flavor's `postprocess` method. return "{$objChr}[[_TOC_]]{$objChr}\n"; } /** * Renders a headline and adds it to the TOC. * This method overloads HeadlineTrait::renderHeadline(). */ protected function renderHeadline($block): string { $tag = 'h' . $block['level']; $id = ''; $content = $this->renderAbsy($block['content']); if ( class_exists('\\IntlChar') && function_exists('mb_str_split') && function_exists('mb_convert_case') ) { $str = $this->unEscapeHtmlEntities( strip_tags($content), ENT_QUOTES | ENT_SUBSTITUTE ); $exploded = mb_str_split($str, 1, 'UTF-8'); foreach ($exploded as $chr) { $type = \IntlChar::charType($chr); if ( $chr === ' ' || $chr === "\t" || $chr === '-' || $chr === '_' || $type === \IntlChar::CHAR_CATEGORY_UPPERCASE_LETTER || $type === \IntlChar::CHAR_CATEGORY_LOWERCASE_LETTER || $type === \IntlChar::CHAR_CATEGORY_TITLECASE_LETTER || $type === \IntlChar::CHAR_CATEGORY_MODIFIER_LETTER || $type === \IntlChar::CHAR_CATEGORY_OTHER_LETTER || $type === \IntlChar::CHAR_CATEGORY_DECIMAL_DIGIT_NUMBER || $type === \IntlChar::CHAR_CATEGORY_LETTER_NUMBER || $type === \IntlChar::CHAR_CATEGORY_CONNECTOR_PUNCTUATION || $type === \IntlChar::CHAR_CATEGORY_NON_SPACING_MARK || $type === \IntlChar::CHAR_CATEGORY_ENCLOSING_MARK || $type === \IntlChar::CHAR_CATEGORY_COMBINING_SPACING_MARK ) { $id .= ($chr === ' ' || $chr === "\t") ? '-' : mb_convert_case($chr, MB_CASE_LOWER, 'UTF-8'); } } if ($id !== '') { $prefix = ($this->getContextId() === '') ? '' : $this->getContextId() . '-'; while (isset($this->headlineAnchorLinks[$id])) { $id .= '-' . $this->headlineAnchorLinks[$id]++; } $this->headlineAnchorLinks[$id] = 1; $this->toc[] = [ 'id' => $id, 'level' => $block['level'], 'content' => $content, ]; $id = ' id="' . $prefix . $this->escapeHtmlEntities( $id, ENT_COMPAT | ENT_SUBSTITUTE ) . '"'; } } return "<{$tag}{$id}>{$content}\n"; } /** * Add Toc's HTML to the parsed HTML. * * @param string $html - The HTML output of Markdown::parse(). * @return string */ public function addToc($html): string { $objChr = "\u{FFFC}"; $toc = ''; $depth = 2; $items = 0; $prefix = ($this->getContextId() === '') ? '' : $this->getContextId() . '-'; if (!empty($this->toc)) { $toc .= "

\n"; foreach ($this->toc as $h) { // Ignore h1; this is the document title. if ($h['level'] < 2) { continue; } // Go deeper in hierarchy if necessary. while ($depth < 6 && $depth < $h['level']) { $depth++; $toc .= "
\n"; } // Go higher in hierarchy if necessary. while ($depth > 2 && $depth > $h['level']) { $depth--; $toc .= "
\n"; } $id = $prefix . $this->escapeHtmlEntities( $h['id'], ENT_COMPAT | ENT_SUBSTITUTE ); $toc .= "
• {$h['content']}
\n"; $items++; } $toc .= '

'; } // Replace TOC placeholder. return str_replace( "{$objChr}[[_TOC_]]{$objChr}", ($items) ? $toc : '', $html ); } abstract protected function renderAbsy($absy); abstract protected function escapeHtmlEntities($text, $flags = 0); abstract protected function unEscapeHtmlEntities($text, $flags = 0); }