curl -F "data={json:'code'}" in PHP? - php

Question

I'm trying to access a third-party API with PHP.
Their command reference is like so:
curl "https://api.example.com/api/" \
-H "Authorization: BEARER-TOKEN" \
-F 'data={"language":"EN","latitude":12.345,"longitude":12.345}'
I've tried:
$url = 'https://api.example.com/api/';
$header = array(
'Content-type: application/json',
'Authorization: ' . $bearertoken
);
$fields = 'data={"language":"EN","latitude":"'.$latitude.'","longitude":"'.$longitude.'"}';
// I've tried this too:
$fields = array('data' => '{"language":"EN","latitude":"'.$latitude.'","longitude":"'.$longitude.'"}');
$ch = curl_init();
$options = array(
CURLOPT_URL => $url,
CURLOPT_POST => true,
CURLOPT_POSTFIELDS => $fields,
CURLOPT_HTTPHEADER => $header,
CURLOPT_RETURNTRANSFER => true,
CURLOPT_HEADER => false,
CURLOPT_FOLLOWLOCATION => true,
CURLOPT_MAXREDIRS => 10,
CURLOPT_ENCODING => "",
CURLOPT_AUTOREFERER => true,
CURLOPT_CONNECTTIMEOUT => 120,
CURLOPT_TIMEOUT => 120
);
curl_setopt_array($ch, $options);
$result = curl_exec($ch);`
But the server responds with a message telling me it didn't get the parameters I'm sending. When I send the same -F "data={}" from a terminal I get the correct response.

Answer 1

You shouldn't use Content-type: application/json. The value of the data parameter is JSON, but the parameters as a whole are sent in application/x-www-form-urlencoded format.
You also need to URL-encode the value of the data parameter.
The best solution is to use json_encode to create the JSON value, then use an array of post fields, then curl will encode the fields properly.
$header = array(
'Authorization: ' . $bearertoken
);
$fields = array('data' =>
json_encode(array('language' => 'EN',
'longitude' => $longitude,
'latitude' => $latitude)));

Answer 2

curl -F submits the form using Content-Type: multipart/form-data, following RFC 2388. You're specifically contravening that when you set the application/json content type.
$data = array('language' => 'EN', 'longitude' => $longitude, 'latitude' => $latitude);
$headers = array (
"Content-Type: multipart/form-data",
"Authorization: $bearertoken",
);
$postfields = array ("data" => json_encode($data));
$ch = curl_init();
$options = array(
CURLOPT_URL => $url,
CURLOPT_HEADER => true,
CURLOPT_HTTPHEADER => $headers,
CURLOPT_POST => true,
CURLOPT_POSTFIELDS => $postfields,
CURLOPT_RETURNTRANSFER => true
);
curl_setopt_array($ch, $options);
curl_exec($ch);
Also, if that's the actual documentation, it may be wrong. The format for Authorization header is Authorization: Bearer <token>.