find a custom data attribute in simple html dom

HTML

<div data-field="regularMarketChange">content</div>

PHP

// basic usage
$tag_search = "[data-field=regularMarketChange]";
$found_item = $item->find($tag_search,0)->plaintext;

// add a test to check the item is not null and will not throw an error or warning
$tag_search = "[data-field=regularMarketChange]";
if(null !== $item->find($tag_search,0)) {
	$found_item = $item->find($tag_search,0)->plaintext;
}