Resolve namespaces with SimpleXML regardless of structure or namespace

Question

I got a Google Shopping feed like this (extract):

Answer 1

The answer given by hakre was well written and exactly what I was looking for, especially the Feed class he provided at the end. But it was incomplete in a couple of ways, so I modified his class to be more generically useful and wanted to share the changes:

• One of the most important issues which was missed in the original is that Attributes may also have namespaces, and without taking that into account, you are quite likely to miss attributes on elements.

• The other bit which is important is that when converting to an array, if you have something which may contain elements of the same name but different namespaces, there is no way to tell which namespace the element was from. (Yes, it's a really rare situation... but I ran into it with a government standard based on NIEM...) So I added a static option which will cause the namespace prefix to be added to all keys in the final array that belong to a namespace. To use it, set Feed::$withPrefix = true; before calling toArray()

• Finally, more for my own preferences, I added an option to toArray() to return the final array as associative instead of using objects.

Here's the updated class:

class Feed extends \SimpleXMLElement implements \JsonSerializable
{
    public static $withPrefix = false;

    public function jsonSerialize()
    {
        $array = array();
        $attributes = array();

        $namespaces = [null] + $this->getDocNamespaces(true);

        // json encode child elements if any. group on duplicate names as an array.
        foreach ($namespaces as $prefix => $namespace) {
            foreach ($this->attributes($namespace) as $name => $attribute) {
                if (static::$withPrefix && !empty($namespace)) {
                    $name = $prefix . ":" . $name;
                }
                $attributes[$name] = $attribute;
            }

            foreach ($this->children($namespace) as $name => $element) {
                if (static::$withPrefix && !empty($namespace)) {
                    $name = $prefix . ":" . $name;
                }
                if (isset($array[$name])) {
                    if (!is_array($array[$name])) {
                        $array[$name] = [$array[$name]];
                    }
                    $array[$name][] = $element;
                } else {
                    $array[$name] = $element;
                }
            }
        }

        if (!empty($attributes)) {
            $array['@attributes'] = $attributes;
        }

        // json encode non-whitespace element simplexml text values.
        $text = trim($this);
        if (strlen($text)) {
            if ($array) {
                $array['@text'] = $text;
            } else {
                $array = $text;
            }
        }

        // return empty elements as NULL (self-closing or empty tags)
        if (!$array) {
            $array = NULL;
        }

        return $array;
    }

    public function toArray($assoc=false) {
        return (array) json_decode(json_encode($this), $assoc);
    }
}