Fix for submitting multiple recipients to a list simultaneously.

src/SendGridPHP/Connect.php

@@ -107,7 +107,18 @@ protected function makeApiCall($url, $postData = NULL, $method = 'POST') {
 		//Set to FALSE to stop cURL from verifying the peer's certificate (needed for local hosts development mostly)
 		if(!$this->_curl_ssl_verify) curl_setopt($session, CURLOPT_SSL_VERIFYPEER, false);
 
-		// Tell curl to use HTTP POST
+        $postData = http_build_query($postData);
+
+        $this->debugCall('DEBUG - Original post querystring: ', urldecode($postData));
+
+        // Replace numerically indexed arrays, such as data[1], data[2], etc. with data[], data[], data[].
+        // This is needed, for instance, when we try to submit multiple email addresses to a List.
+        // The postdata is url_encoded at this point, so replace using %5B = [, %5D = ].
+        $postData = preg_replace('/%5B\d+%5D/', '%5B%5D', $postData);
+
+        $this->debugCall('DEBUG - Replaced post querystring: ', urldecode($postData));
+
+        // Tell curl to use HTTP POST
 		curl_setopt ( $session, CURLOPT_CUSTOMREQUEST, strtoupper ( $method ) );
 		// Tell curl that this is the body of the POST
 		curl_setopt ($session, CURLOPT_POSTFIELDS, $postData);

src/SendGridPHP/Newsletter.php

@@ -200,10 +200,22 @@ public function newsletter_lists_delete($list) {
 	public function newsletter_lists_email_add($list , $data) {
 		$url = "newsletter/lists/email/add";
 
+        /**
+         * SendGrid, in their wisdom, requires that we submit each recipient in the list
+         * as a separate parameter.
+         *
+         * Since PHP does not support multiple params with the same name, we stuff them into an array.
+         *
+         * SendGridPHP\Connect's makeApiCall method removes the numerical indexes in the generated querystring.
+         */
+        array_walk($data, function(&$row) {
+            $row = json_encode($row);
+        });
+
 		$postData = array(
 			'list' => $list,
-			'data' => json_encode($data),
-		  );
+			'data' => $data,
+        );
 
 		$results = $this->makeApiCall ( $url , $postData );