How to combine the text node of 2 pieces of extracted data using Goutte/Domcrawler

I've been trying to figure out how to combine two pieces of extracted text into a single result (array). In this case, the title and subtitle of a variety of books.

<td class="item_info">
  <span class="item_title">Carrots Like Peas</span>
  <em class="item_subtitle">- And Other Fun Facts</em>
</td>

The closest I've been able to get is:

$holds = $crawler->filter('span.item_title,em.item_subtitle');

Which I've managed to output with the following:

$holds->each(function ($node) {
    echo '<pre>';
    print $node->text();
    echo '</pre>';
});

And results in

<pre>Carrots Like Peas</pre>
<pre>- And Other Fun Facts</pre>

Another problem is that not all the books have subtitles, so I need to avoid combining two titles together. How would I go about combining those two into a single result (or array)?

Solution

In my case, I took a roundabout way to get where I wanted to be. I stepped back one level in the DOM to the td tag and grabbed everything and dumped it into the array.

I realized that DomCrawler's documentation had the example code to place the text nodes into an array.

$items_out = $crawler->filter('td.item_info')->each(function (Crawler $node, $i) {
    return $node->text();   
});

I'd tried to avoid capturing the td because author's were also included in those cells. After even more digging, I was able to strip the authors from the array with the following:

foreach ($items_out as &$items) {
    $items = substr($items,0, strpos($items,' - by'));
}

Just took me five days to get it all sorted out. Now onto the next problem!