CURL: Send images with boundary to REST API

Question

Im currently working with some kind of API. I have wrote simple functions which allows me to add new content, however Im stuck on uploading images.

Here\'s simple CURL c

Answer 1

After several approaches using curl_file_create without getting it to work. I think the mobile.de-API is just implemented badly.

I ended up implementing a custom routine for CURLOPT_POSTFIELDS that is creating the complete multipart manually. I borrowed most of the code from the PHP manpage as "The CURLFile class".

1. Create an array of the filenames

2. Create multipart header (see code below)

   function curl_custom_postfields(array $files = array())    {
   
   // build file parameters
   foreach ($files as $k => $v) {
       switch (true) {
           case false === $v = realpath(filter_var($v)):
           case !is_file($v):
           case !is_readable($v):
               continue; // or return false, throw new InvalidArgumentException
       }
       $data = file_get_contents($v);
       $body[] = implode("\r\n", array(
           "Content-Disposition: form-data; name=\"image\"",
           "Content-Type: image/jpeg",
           "",
           $data,
       ));
   }
   
   // generate safe boundary
   do {
       $boundary = "---------------------" . md5(mt_rand() . microtime());
   } while (preg_grep("/{$boundary}/", $body));
   
   // add boundary for each parameters
   array_walk($body, function (&$part) use ($boundary) {
       $part = "--{$boundary}\r\n{$part}";
   });
   
   // add final boundary
   $body[] = "--{$boundary}--";
   $body[] = "";
   
   // set options
   return array(implode("\r\n", $body), $boundary);    
   }
   

3. Use that function ;)

   $postfields = $this->curl_custom_postfields($files);
   

4. Add boundary to http header

   curl_setopt($ch, CURLOPT_HTTPHEADER, array('Content-Type: multipart/form-data; boundary=' . $postfields[1], 'Accept: application/vnd.de.mobile.api+json'));
   

5. Add Postfields

   curl_setopt($ch, CURLOPT_POSTFIELDS, $postfields[0]);
   

It's not the cleanest solution at all so please use it with care. But at least it works.

Answer 2

I have the same problem and found a solution but only for single images. The trick is that your array MUST look like these:

$images = array(
  'image' => 'PATH/IMG.jpg',
);

That means that the the key must be "image" and nothing other! I hope that helps ;)