/** * * {@inheritDoc} * * @see \Core\Html\HtmlBuildableInterface::build() */ public function build() { // No content, no output if (empty($this->content)) { throw new HtmlException('There is no content set for this panel.'); } foreach ($this->content as $content) { if ($content instanceof HtmlBuildableInterface || is_object($content) && method_exists($content, 'build')) { $content = $content->build(); } $this->html->addInner($content); } return $this->html->build(); }