SimpleXML Iterator
The SimpleXML iterator allows you to use SimpleXML objects with the other iterator classes. This allows you to easily construct an SQL-like interface to XML files.
For instance, suppose you have an XML address book like the one in Example 5-1. However, instead of containing only 2 records, it contains hundreds of records, and you want to display the records in groups of 10.
One solution is to place the information into a database. Another is
to use XPath. A third is to combine a
SimpleXMLIterator with a
LimitIterator:
$ab = file_get_contents('address-book.xml');
$page = 0;
$limit = 10;
foreach (new LimitIterator(new SimpleXMLIterator($ab),
$page * $limit, $limit) as $person) {
print "$person->firstname $person->lastname: $person->email\n";
}The SimpleXMLIterator takes a string of XML and
creates an iterable SimpleXML object. Here, it’s
parsing address-book.xml.
This iterator is then passed to a LimitIterator
that restricts the output to only the $limit
number of records beginning at $page * $limit.
When $page is 0, it returns the
first 10 records; when $page is
1, you get records 11 through 20.
The $person item can be treated like a
SimpleXMLElement, so
$person->firstname returns the text stored in
the firstname element.