无法在数组PHP中获取变量字符串

Question

我希望在点击此链接后获取新闻内容。

所以，我尝试使用我的代码：

$crawler = $this->client->request('GET', 'http://giaitri.vnexpress.net');

$news = $crawler->filter('#news_home > li');
$link = null;
$news = $crawler->filter('#news_home > li')->each(function($node) {
    $link = $node->filter('.txt_link');
    $child_news = $this->client->click($link->link());
    print_r($child_news->filter('#left_calculator')->text());
    if(!empty($child_news->filter('#left_calculator'))) {
        return [
        'title' => $link->text(),
        'link'  => $link->link()->getUri(),
        'thumbnail' => $node->filter('.txt_link img')->attr('src'),
        'description' => trim($node->filter('.news_lead')->text()),
        'content' => trim($child_news->filter('#left_calculator')->text()),
        ];
    }
});

print_r($child_news->filter('#left_calculator')->text())有值。

但是在阵列中：

'content' => trim($child_news->filter('#left_calculator')->text()),

显示如下错误：

The current node list is empty.