MailChimp API: Batch Check Subscription Status - php

Question

What's the best way to check a batch of email addresses and whether or not they are subscribed to a particular list? My current method is making an API call for each email address, but this becomes very slow when the count becomes > 50.
I'm using V2.0, using PHP methods since I'm developing on CakePHP.
//Determine MailChimp Subscription
$args = array(
'id' => $this->apiKeys['mailchimp_list_ID'],
'emails' => array(1 => array('email' => $customer['User']['username']))
);
$mailChimpQuery = $this->mailChimp('member-info', $args);
$mailChimpStatus = ($mailChimpQuery['success_count'] == 1 ? 1 : 0);
$customer['Customer']['subscribed'] = $mailChimpStatus;
The mailChimp call in another Controller is:
public function mailChimp($action, $args=array()) {
$args['apikey'] = $this->apiKeys['mailchimp_api'];
$url = 'https://us8.api.mailchimp.com/2.0/lists/' . $action .'.json';
if (function_exists('curl_init') && function_exists('curl_setopt')){
$ch = curl_init();
curl_setopt($ch, CURLOPT_URL, $url);
curl_setopt($ch, CURLOPT_HTTPHEADER, array('Content-Type: application/json'));
curl_setopt($ch, CURLOPT_USERAGENT, 'PHP-MCAPI/2.0');
curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
curl_setopt($ch, CURLOPT_TIMEOUT, 10);
curl_setopt($ch, CURLOPT_POST, true);
curl_setopt($ch, CURLOPT_SSL_VERIFYPEER, false);
curl_setopt($ch, CURLOPT_POSTFIELDS, json_encode($args));
$result = curl_exec($ch);
curl_close($ch);
} else {
$json_data = json_encode($args);
$result = file_get_contents($url, null, stream_context_create(array(
'http' => array(
'protocol_version' => 1.1,
'user_agent' => 'PHP-MCAPI/2.0',
'method' => 'POST',
'header' => "Content-type: application/json\r\n".
"Connection: close\r\n" .
"Content-length: " . strlen($json_data) . "\r\n",
'content' => $json_data,
),
)));
}
return $result ? json_decode($result, true) : false;
}

Answer 1

FYI, I came up with my own solution:
Create an array of all the email addresses in the database
Create a for-loop that takes segments of 50 email addresses from that array and runs a batch check using member-info (https://apidocs.mailchimp.com/api/2.0/lists/member-info.php)
Manipulate the return array from the API call to extract only the email address and whether or not it's subscribed to the list.
Within the for-loop, add each 50 email addresses return values into a new array and then by the end of it; you'll have an array of all the email addresses in your database with a corresponding true/false value depending on whether or not they are subscribed to the list.
Good luck!