How to read child of interleaved XML in PHP

Question

We need to update a somewhat old API a customer is using. We're getting the data with simplexml_load_file. The new structure is a bit more complex and I could not find a way to retrieve the new data.

The new structure looks like this:

Before we used $ratingPrice = $xml->hotel->ratingPrice; to get a value.

Now, I need to retrieve $xml->business->subcategoryRating->subcategoryRating->averageRating. I'm now stuck with that.

How am I able to get the average rating of wifi, or location and have them outputted in single variables?

Also, don't forget the `s` on the first `subcategoryRatings`. — Nomis, Mar 23 '18 at 16:01
Possible duplicate of [How do you parse and process HTML/XML in PHP?](https://stackoverflow.com/questions/3577641/how-do-you-parse-and-process-html-xml-in-php) — IncredibleHat, Mar 23 '18 at 16:02
@IncredibleHat But how can I access a value directly? Lets say I just want Location, how would I do that? I cannot use [0], [1] etc for this. — Andreas, Mar 23 '18 at 16:04

score 1 · Answer 1 · answered Mar 23 '18 at 16:08

If the order of your information is always the same (eg. Wi-Fi, Location, Apartment, Cleanliness) then you can do

$xml->business->subcategoryRating->subcategoryRating[x]->averageRating

so the x is the index of your xml list. Then

...subcategoryRating[0]->averageRating

corresponds to Wi-Fi and

...subcategoryRating[1]->averageRating

corresponds to Location and so forth.

Nigel Ren · Accepted Answer · 2018-03-23T16:43:29.767

You can extract the various ratings into an array and then use the relevant index to process the data your after. This uses the id attribute of the (for example) <category id="location"> element to use as the index...

$ratings = [];
foreach ( $xml->business->subcategoryRatings->subcategoryRating as $rating )    {
    $ratings[(string)$rating->category['id']] = (string)$rating->averageRating;
}

echo $ratings["location"].PHP_EOL;

This last line will need to be updated to access the particular element your after.

score 0 · Answer 3 · answered Mar 23 '18 at 17:00

As an alternative you could create an xpath expression and use xpath.

That would give you array of SimpleXMLElement objects.

$xml = simplexml_load_string($data);
$expression = '//business/subcategoryRatings/subcategoryRating[category[@id="wifi" or @id="location"]]';
foreach($xml->xpath($expression) as $item) {
    $averageRating = (string)$item->averageRating;    
}

How to read child of interleaved XML in PHP

3 Answers3