PHP and cURL - Multiform request with file and text - php

Question

I need to send a cURL request containing a file to upload as well as a JSON string. I can get a properly formatted request when sending the JSON, but the file is throwing it off.
$postData = array(
'JSON'=> json_encode($jsonParams),
$reference => '#'.$tmp_file_path
);
//Borrowed function from: http://scraperblog.blogspot.com/2013/07/php-curl-multipart-form-posting.html
function multipart_build($fields, $boundary){
$retval = '';
foreach($fields as $key => $value){
$retval .= "--$boundary\nContent-Disposition: form-data; name=\"$key\"\n\n$value\n";
}
$retval .= "--$boundary--";
return $retval;
}
$boundary = "--requestboundary-xxx";
$request = $this->multipart_build($postData,$boundary);
$curl = curl_init();
curl_setopt($curl, CURLOPT_SSL_VERIFYPEER, false); // stop verifying certificate
curl_setopt($curl, CURLOPT_RETURNTRANSFER, true);
curl_setopt($curl, CURLOPT_HTTPHEADER, array("Content-Type: multipart/form-data; boundary=$boundary"));
curl_setopt($curl, CURLOPT_URL, $target);
curl_setopt($curl, CURLOPT_POST, true);
curl_setopt($curl, CURLOPT_POSTFIELDS, $request);
$response = curl_exec($curl);
$info = curl_getinfo($curl);
curl_close($curl);
The $reference needs to be tied to a value in the $jsonParams so the receiving server can ensure uploaded files are attached to the corresponding data string packages.
////////////////////////////////////////////////////////////
Update after Marc B's comment
////////////////////////////////////////////////////////////
So my first approach wasn't using my own multipart. The reason I went with multipart was at least I was getting a response from the server. Here is the original code.
$curl_file_object = curl_file_create($attachmentFile['tmp_name'], $attachmentFile['type'], $reference);
$postData= array(
'JSON'=> json_encode($jsonParams),
$reference => $curl_file_object,
);
$curl = curl_init();
curl_setopt($curl, CURLOPT_URL, $target);
curl_setopt($curl, CURLOPT_SSL_VERIFYPEER, false); // stop verifying certificate
curl_setopt($curl, CURLOPT_RETURNTRANSFER, true);
curl_setopt($curl, CURLOPT_HEADER, true);
curl_setopt($curl, CURLOPT_HTTPHEADER, array("Content-Type: multipart/form-data;"));
curl_setopt($curl, CURLOPT_POST, true); // enable posting
curl_setopt($curl, CURLOPT_POSTFIELDS, $postData); // post data
curl_setopt($curl, CURLOPT_FOLLOWLOCATION, true); // if any redirection after upload
$response = curl_exec($curl);
$info = curl_getinfo($curl);
curl_close($curl);
debug($info);
And with this I get:
[url] => --------
[content_type] =>
[http_code] => 0
[header_size] => 0
[request_size] => 0
[filetime] => -1
[ssl_verify_result] => 0
[redirect_count] => 0
[total_time] => 0.031
[namelookup_time] => 0
[connect_time] => 0.031
[pretransfer_time] => 0
[size_upload] => 0
[size_download] => 0
[speed_download] => 0
[speed_upload] => 0
[download_content_length] => -1
[upload_content_length] => -1
[starttransfer_time] => 0
[redirect_time] => 0
[redirect_url] =>
[primary_ip] => --------
[certinfo] => Array
(
)
[primary_port] => --------
[local_ip] => --------
[local_port] => --------
With the multipart I was at least getting a 400.

Answer 1

Don't built your own multipart. Curl is perfectly capable of doing that for you:
curl_setopt($curl, CURLOPT_POSTFIELDS, $postData);
it'll take an array and do whatever's needed automatically.
And if you're on PHP 5.5+, you can use curlfile for the file part as well, without the # hack.

Answer 2

Using CURLFile instead of curl_file_create() fixed the problem. Even though they are supposed to be the same...