think\Template::parseInclude PHP Method

    private function parseInclude(&$content)
    {
        $regex = $this->getRegex('include');
        $func = function ($template) use(&$func, &$regex, &$content) {
            if (preg_match_all($regex, $template, $matches, PREG_SET_ORDER)) {
                foreach ($matches as $match) {
                    $array = $this->parseAttr($match[0]);
                    $file = $array['file'];
                    unset($array['file']);
                    // 分析模板文件名并读取内容
                    $parseStr = $this->parseTemplateName($file);
                    foreach ($array as $k => $v) {
                        // 以$开头字符串转换成模板变量
                        if (0 === strpos($v, '$')) {
                            $v = $this->get(substr($v, 1));
                        }
                        $parseStr = str_replace('[' . $k . ']', $v, $parseStr);
                    }
                    $content = str_replace($match[0], $parseStr, $content);
                    // 再次对包含文件进行模板分析
                    $func($parseStr);
                }
                unset($matches);
            }
        };
        // 替换模板中的include标签
        $func($content);
        return;
    }