Check if XML element is existing in loop - php

Question

For a website i'm making i need to get data from an external XML file.
I load the data like this:
$doc = new DOMDocument();
$url = 'http://myurl/results/xml/12345';
if (!$doc->load($url))
{
echo json_encode(array('error'=> 'error'));
exit;
}
$xpath = new DOMXPath($doc);
$program_date = $xpath->query('//game/date');
Then i use a foreach loop to get all the data
if($program_date){
foreach($program_date as $node){
$programArray['program_date'][] = $node->nodeValue;
}
}
The problem i'm having is that sometimes a certain game doesn't have a date.
So when a game doesn't have a date, i just want it to put "-", instead of the date from the XML file. My problem is that i don't know how to check if a date is present in the data.
I used a lot of ways like isset, !isset, else, !empty, empty
$teamArray['program_kind'][] = "-";
but noting works...
Can someone help me with this problem?
Thanks in advance

Answer 1

You need to iterate the game elements, use them as a context and fetch the data with additional XPath expressions.
But one thing first. Use DOMXPath::evaluate(). DOMXPath::query() only supports location paths. It can only return a node list. But XPath expressions can return scalar values, too.
$xpath = new DOMXPath($doc);
$games = $xpath->evaluate('//game');
The result of //game will always be a DOMNodeList object. It can be an empty list, but you can directly iterate it. A condition like if ($games) will always be true.
foreach ($games as $game) {
Now that you have the game element node, you can use it as an context to fetch other data.
$date = $xpath->evaluate('string(date)', $game);
string() casts the first node of the location path into a string. If it can not match a node, it will return an empty string. Check normalize-space() if you want to remove whitespaces at the same time.
You can validate if the game element has a date node using count().
$hasDate = $xpath->evaluate('count(date) > 0', $game);
The result of this XPath expression is always a boolean.