How to Paginate lines in a foreach loop with PHP

Question

Using the following code to display a list of friends from my twitter profile. Id like to only load a certain number at a time, say 20, then provide pagination links at the

Answer 1

If you're loading the full dataset every time, you could be pretty direct about it and use a for loop instead of a foreach:

$NUM_PER_PAGE = 20;

$firstIndex = ($page-1) * $NUM_PER_PAGE;

$xml = simplexml_load_string($rawxml);
for($i=$firstIndex; $i<($firstIndex+$NUM_PER_PAGE); $i++)
{
        $profile = simplexml_load_file("https://twitter.com/users/".$xml->id[$i]);
        $friendscreenname = $profile->{"screen_name"};
        $profile_image_url = $profile->{"profile_image_url"};
        echo "<a href=$profile_image_url>$friendscreenname</a><br>";
}

You'll also need to limit $i to the array length, but hopefully you get the gist.

Answer 2

A very elegant solution is using a LimitIterator:

$xml = simplexml_load_string($rawxml);
// can be combined into one line
$ids = $xml->xpath('id'); // we have an array here
$idIterator = new ArrayIterator($ids);
$limitIterator = new LimitIterator($idIterator, $offset, $count);
foreach($limitIterator as $value) {
    // ...
}

// or more concise
$xml = simplexml_load_string($rawxml);
$ids = new LimitIterator(new ArrayIterator($xml->xpath('id')), $offset, $count);
foreach($ids as $value) {
    // ...
}