How to POST JSON Data With PHP cURL?

Question

Here is my code,

$url = 'url_to_post';
$data = array(
    "first_name" => "First name",
    "last_name" => "last name",
    "email"=>"[email protected]",
    "addresses" => array (
        "address1" => "some address",
        "city" => "city",
        "country" => "CA",
        "first_name" =>  "Mother",
        "last_name" =>  "Lastnameson",
        "phone" => "555-1212",
        "province" => "ON",
        "zip" => "123 ABC"
    )
);
$data_string = json_encode($data);
$ch=curl_init($url);
curl_setopt($ch, CURLOPT_CUSTOMREQUEST, "POST");
curl_setopt($ch, CURLOPT_POSTFIELDS, array("customer"=>$data_string));
curl_setopt($ch, CURLOPT_HEADER, true);
curl_setopt($ch, CURLOPT_HTTPHEADER,
    array(
        'Content-Type:application/json',
        'Content-Length: ' . strlen($data_string)
    )
);

$result = curl_exec($ch);
curl_close($ch);

And at other page, I am retrieving post data.

    print_r ($_POST);

Output is

HTTP/1.1 200 OK
Date: Mon, 18 Jun 2012 07:58:11 GMT
Server: Apache
X-Powered-By: PHP/5.3.6
Vary: Accept-Encoding
Connection: close
Content-Type: text/html

Array ( ) 

So, I am not getting proper data even at my own server, it's empty array. I want to implement REST using json as at http://docs.shopify.com/api/customer#create

Answer 1

You are POSTing the json incorrectly -- but even if it were correct, you would not be able to test using print_r($_POST) (read why here). Instead, on your second page, you can nab the incoming request using file_get_contents("php://input"), which will contain the POSTed json. To view the received data in a more readable format, try this:

echo '<pre>'.print_r(json_decode(file_get_contents("php://input")),1).'</pre>';

In your code, you are indicating Content-Type:application/json, but you are not json-encoding all of the POST data -- only the value of the "customer" POST field. Instead, do something like this:

$ch = curl_init( $url );
# Setup request to send json via POST.
$payload = json_encode( array( "customer"=> $data ) );
curl_setopt( $ch, CURLOPT_POSTFIELDS, $payload );
curl_setopt( $ch, CURLOPT_HTTPHEADER, array('Content-Type:application/json'));
# Return response instead of printing.
curl_setopt( $ch, CURLOPT_RETURNTRANSFER, true );
# Send request.
$result = curl_exec($ch);
curl_close($ch);
# Print response.
echo "<pre>$result</pre>";

Sidenote: You might benefit from using a third-party library instead of interfacing with the Shopify API directly yourself.