How to send and receive data to/from an API using CURL? - php

Question

I have to make an API. For this, I will receive the data from the mobile devices as JSON using POST. I have to work with this data and send the response back to the devices also as JSON.
But I don't know how to take the data that I will receive. I have tried to make some tests using CURL to see how can I take this data but the $_POST is always empty. Can you please tell me how to send the data as JSON format to the API using CURL and how can I receive this data so I can work with it and send it back as response?
These are my test files:
curl.php:
//set POST variables
$url = 'http://test.dev/test.php';
$data = array(
'fname' => 'Test',
'lname' => 'TestL',
'test' => array(
'first' => 'TestFirst',
'second' => 'TestSecond'
)
);
//open connection
$ch = curl_init($url);
$json_data = json_encode($data);
curl_setopt($ch, CURLOPT_CUSTOMREQUEST, "POST");
curl_setopt($ch, CURLOPT_POSTFIELDS, $json_data);
curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
curl_setopt($ch, CURLOPT_HTTPHEADER, array(
'Content-Type: application/json',
'Content-Length: ' . strlen($json_data))
);
// execute post
$result = curl_exec($ch);
echo $result;
//close connection
curl_close($ch);
test.php:
var_dump($_POST);
The response that I get is:
array(0) { }

Answer 1

You need to pass the POST data as a URL query string or as an array, the problem is you post data in JSON format, but PHP does not parse JSON automatically, so the $_POST array is empty. If you want it, you need do the parsing yourself in the test.php:
$raw_post = file_get_contents("php://input");
$data = json_decode($raw_post, true);
print_r($data);
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