You should GET that file directly, via, for example, CURL. Then parse it, if it comes in JSON, you can use json-decode.
Simple example (slightly modified version of code found here):
<?php
$url = "http://www.example.co.uk/includes/js/data.js";
curl_setopt($ch, CURLOPT_URL, $url);
curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
...
$output = curl_exec($ch);
$info = curl_getinfo($ch);
if ($output === false || $info['http_code'] != 200) {
$error = "No cURL data returned for $url [". $info['http_code']. "]";
if (curl_error($ch))
$error .= "\n". curl_error($ch);
}
else {
$js_data = json_decode($output);
// 'OK' status; save $class members in the database, or the $output directly,
// depending on what you want to actually do.
...
}
//Display $error or do something about it
?>