[SalesForce] How to upload 6Mb attachment in a custom Apex Rest service (heap size issue)

You're very close - the tricky bit is that the Chatter REST API is expecting a multipart form. Also, it wants the message segments as its own array. After some poking around it looks like the easiest way to handle it is by wrangling the post data together.

I'm using this doc as a base: http://www.salesforce.com/us/developer/docs/chatterapi/Content/intro_input.htm

And here is my script, note that I pasted the url manually (which you should not):

    <?php
    $url = "https://na15.salesforce.com/services/data/v29.0/chatter/feeds/record/500i0000004AcIq/feed-items";
    $curl = curl_init();
    curl_setopt($curl, CURLOPT_URL, $url);
    curl_setopt($curl, CURLOPT_CUSTOMREQUEST, "POST");

    $fileName = basename($file);

    $headers = array();
    $headers[] = "Authorization: OAuth {token}";
    $headers[] = 'Content-Type: multipart/form-data; boundary=F9jBDELnfBLAVmLNbnLIYibT5Icp0h3VJ7mkI';

    $segments = array();
    $segments['type'] = 'Text';
    $segments['text'] = 'User uploaded attachment';

    $message = array();
    $message[] = $segments;

    $dataArray = array(
        'body' => array(
            'messageSegments' => $message
        ),
        'attachment' => array(
            'attachmentType' => 'NewFile',
            'title' => 'Test File'
        )
    );

    $data = $data.json_encode($dataArray);
    $file = realpath('phoenix-logo.png');


    $post_text = '--F9jBDELnfBLAVmLNbnLIYibT5Icp0h3VJ7mkI
Content-Disposition: form-data; name="json"
Content-Type: application/json; charset=UTF-8

{ "body":
   {
      "messageSegments" : [
      {
         "type" : "Text", 
         "text" : "Here is another file for review."
      }, {
         "type" : "Hashtag", 
         "tag" : "important"
      }, {
         "type" : "Text", 
         "text" : "Again, please review this as soon as possible."
      }
      ]
   }, 
   "attachment": 
   {
      "attachmentType" : "NewFile",
      "description": "Phoenix Logo",
      "title" : "Logo.png"
   }
}

--F9jBDELnfBLAVmLNbnLIYibT5Icp0h3VJ7mkI
Content-Disposition: form-data; name="feedItemFileUpload"; filename="logo.png"
Content-Type: image/png

'.file_get_contents($file).'

--F9jBDELnfBLAVmLNbnLIYibT5Icp0h3VJ7mkI--';

    curl_setopt($curl, CURLOPT_HTTPHEADER, $headers);
    curl_setopt($curl, CURLOPT_POST, true);
    curl_setopt($curl, CURLOPT_VERBOSE, 1);
    curl_setopt($curl, CURLOPT_POSTFIELDS, $post_text);
    curl_setopt($curl, CURLOPT_RETURNTRANSFER, true);
    curl_setopt($curl, CURLINFO_HEADER_OUT, true);

    $response_json = curl_exec($curl);

    print $response_json;
    ?>

You can use Bulk API here to upload attachment in bulk.

• First, you need to Create a request.txt File which will include details of files.

• Then Create a Zip Batch File with Binary Attachments

• Then Create a Job for Batches with Binary Attachments

• Finally, Create a Batch with Binary Attachments.

You can follow the details steps from here: Load Binary Attachments