[PHP] Any way to attach a file to an invoice?

I read https://www.zoho.com/books/api/v3/invoices/attachment/#add-attachment-to-an-invoice.

It seems should be "multipart/form-data". However, I can not predict the exact form of the data I have to send a file to the server.

Maybe someone can help me with working example or give any fresh idea?

In my PHP code, I use some params in curl as part of $zoho ->makeApiRequest.

curl_setopt(
  $ch,
  CURLOPT_HTTPHEADER,
  array('Content-Type: multipart/form-data')
);

curl_setopt($ch, CURLOPT_POST, TRUE); // enable posting
curl_setopt($ch, CURLOPT_POSTFIELDS, $query);

In my common script I am trying to send the data via:

//Zoho Exception: {"code":33003,"message":"No Documents have been attached."}
$parameters = $_FILES['form-xlsx'];

//Zoho Exception: {"code":2,"message":"The request passed is not valid."}
$parameters = array(
  'content' => new \CurlFile(
    __DIR__ . $invoice_attachment,
    $_FILES['form-xlsx']['type'],
    basename($invoice_attachment)
  ),
);

//Zoho Exception: {"code":2,"message":"The request passed is not valid."}
$parameters = array(
  new \CurlFile(
    __DIR__ . $invoice_attachment,
    $_FILES['form-xlsx']['type'],
    basename($invoice_attachment)
  ),
);

//Zoho Exception: {"code":33003,"message":"No Documents have been attached."}
$parameters = new \CurlFile(
  __DIR__ . $invoice_attachment,
  $_FILES['form-xlsx']['type'],
  basename($invoice_attachment)
);

//Zoho Exception: {"code":2,"message":"Invalid value passed for content"}
$parameters = array(
  'content' => file_get_contents(__DIR__ . $invoice_attachment),
);

//Zoho Exception: {"code":2,"message":"Invalid value passed for 0"}
$parameters = array(
  file_get_contents(__DIR__ . $invoice_attachment),
);

//Zoho Exception: {"code":2,"message":"The request passed is not valid."}
$parameters = file_get_contents(__DIR__ . $invoice_attachment);

//Zoho Exception: {"code":2,"message":"Invalid value passed for content"}
$parameters = array(
  'content' => base64_encode(
    file_get_contents(__DIR__ . $invoice_attachment)
  ),
);

// Zoho Exception: {"code":2,"message":"Invalid value passed for 0"}
$parameters = array(
  base64_encode(
    file_get_contents(__DIR__ . $invoice_attachment)
  ),
);

// Zoho Exception: {"code":2,"message":"The request passed is not valid."}
$parameters = base64_encode(
  file_get_contents(__DIR__ . $invoice_attachment)
);

try {
  $attachment = $zoho->makeApiRequest(
    'invoices/' . $invoice_id . '/attachment',
    'POST',
    $parameters,
    FALSE,
    TRUE
  );
} catch (Exception $e) {
  logger('Zoho Exception', $zoho->lastRequest['dataRaw']);

}

nothing work.

from logs:

Verbose information:

* Hostname books.zoho.com was found in DNS cache
*   Trying 74.201.154.210...
* Connected to books.zoho.com (74.201.154.210) port 443 (#0)
* Cipher selection: ALL:!EXPORT:!EXPORT40:!EXPORT56:!aNULL:!LOW:!RC4:@STRENGTH
* successfully set certificate verify locations:
*   CAfile: f:/openserver/modules/php/PHP-5.5/cacert.pem
  CApath: none
* NPN, negotiated HTTP1.1
* SSL connection using TLSv1.2 / ECDHE-RSA-AES128-GCM-SHA256
* Server certificate:
* 	 subject: C=IN; postalCode=600089; ST=Tamilnadu; L=Chennai; street=Block 7 , DLF IT Park,Ramapuram; O=ZOHO Corporation; OU=ZOHO; OU=PremiumSSL Wildcard; CN=*.zoho.com
* 	 start date: 2016-10-12 00:00:00 GMT
* 	 expire date: 2017-02-26 23:59:59 GMT
* 	 subjectAltName: books.zoho.com matched
* 	 issuer: C=GB; ST=Greater Manchester; L=Salford; O=COMODO CA Limited; CN=COMODO SHA-256 Organization Validation Secure Server CA
* 	 SSL certificate verify ok.
> POST /api/v3/invoices/159812000000849219/attachment?authtoken=68f4de7fed68ef605138c79c8e64e1cc&organization_id=58124894 HTTP/1.1
Host: books.zoho.com
Accept: */*
Content-Length: 147
Expect: 100-continue
Content-Type: multipart/form-data; boundary=------------------------894a5eaf9a450884

< HTTP/1.1 100 Continue
< HTTP/1.1 400 Bad Request
< Server: ZGS
< Date: Tue, 17 Jan 2017 12:40:06 GMT
< Content-Type: application/json;charset=UTF-8
< Transfer-Encoding: chunked
< Connection: keep-alive
< Set-Cookie: d963a4f87b=4ee0acb6d94af1624d87fd7fda6f8d92; Path=/
< X-XSS-Protection: 1
< X-Content-Type-Options: nosniff
< Set-Cookie: zbcscook=9e775632-3428-47ac-bf42-a1dcfb2ad531; Path=/; Secure
< Pragma: no-cache
< Cache-Control: no-store, no-cache, must-revalidate, max-age=0, post-check=0, pre-check=0
< Expires: Thu, 01 Jan 1970 00:00:00 GMT
< X-Frame-Options: NONE
< Set-Cookie: JSESSIONID=2B6C22E834493F5A2C9FED42A7612CA3; Path=/; Secure; HttpOnly
< X-Rate-Limit-Limit: 2500
< X-Rate-Limit-Reset: 58793
< X-Rate-Limit-Remaining: 2349
< Content-Disposition: attachment;
< Allow: OPTIONS, POST, GET, DELETE, PUT
< Set-Cookie: BuildCookie_58124894=1; Expires=Tue, 17-Jan-2017 12:45:06 GMT; Secure
< BUILD_VERSION: Jan_16_2017_2347
< CLIENT_BUILD_VERSION: Jan_16_2017_2347
< SERVER_BUILD_VERSION: Jan_10_2017_1_21185/
< Vary: Accept-Encoding
* HTTP error before end of send, stop sending
< 
* Closing connection 0

Zoho Exception: {"code":33003,"message":"No Documents have been attached."}

Thank you very much in advance!