how to add variable php parameters to urlencoded strings from Postman - php

Question

I am testing an api on postman. The request body should be in x-www-form-url-encoded. My requests are being passed successfully, and am able to generate a snippet which I have shared here. However, some of the parameters that am adding to the body (Amount, and phone number) will not be static when the api is employed on my site. These parameters will vary by user. I have tried to define those parameters at the top of the code as you cane see $Airtime_amount and
$Recieving_mobile, but how can I pass them to the x-www-form-url-encoded CURLOPT_POSTFIELDS in the code below? See how am trying to pass them, but without success...
In other words, I have a url encoded string from postman, but the parameters in that string are static. i would like to make them dynamic..Like get user phone number from wordpress, and insert it in the urlencoded string
//Wordpress hook to call the api begins here
add_action('hrw_withdrawal_request_notification','disburse_airtime',7);
function disburse_airtime() {
$Airtime_amount = "KES 230";
$Recieving_mobile = "[phone]";
//Snippet generated from postman begins here
$curl = curl_init();
curl_setopt_array($curl, array(
CURLOPT_URL => 'https://api.sandbox.africastalking.com/version1/airtime/send',
CURLOPT_RETURNTRANSFER => true,
CURLOPT_ENCODING => '',
CURLOPT_MAXREDIRS => 10,
CURLOPT_TIMEOUT => 0,
CURLOPT_FOLLOWLOCATION => true,
CURLOPT_HTTP_VERSION => CURL_HTTP_VERSION_1_1,
CURLOPT_CUSTOMREQUEST => 'POST',
CURLOPT_POSTFIELDS => 'username=sandbox&recipients=%5B%7B%22phoneNumber%22%3D%3E%24Recieving_mobile%2C%22amount%22%3D%3E%24Airtime_amount%7D%5D',
CURLOPT_HTTPHEADER => array(
'Content-Type: application/x-www-form-urlencoded',
'apiKey: 61449ca078574078a6d0eaaa01cfb751f803797c99714f74d8541a25e2a612ef',
'Accept: application/json'
),
));
$response = curl_exec($curl);
curl_close($curl);
echo $response;
}

Answer 1

You should probably build the POSTFIELDS string using the http_build_query function.
Your existing string has what looks like a JSON string for the value of the recipients parameter, so we can build that up using arrays, then encode it when we set it in the params.
function disburse_airtime()
{
$Airtime_amount = "KES 230";
$Recieving_mobile = "[phone]";
$recipients = [
[
'phoneNumber' => $Recieving_mobile,
'amount' => $Airtime_amount
]
];
$params = [
'username' => 'sandbox',
'recipients' => json_encode($recipients)
];
$postFields = http_build_query($params);
$curl = curl_init();
curl_setopt_array($curl, [
CURLOPT_URL => 'https://api.sandbox.africastalking.com/version1/airtime/send',
CURLOPT_RETURNTRANSFER => true,
CURLOPT_ENCODING => '',
CURLOPT_MAXREDIRS => 10,
CURLOPT_TIMEOUT => 0,
CURLOPT_FOLLOWLOCATION => true,
CURLOPT_HTTP_VERSION => CURL_HTTP_VERSION_1_1,
CURLOPT_CUSTOMREQUEST => 'POST',
CURLOPT_POSTFIELDS => $postFields,
CURLOPT_HTTPHEADER => [
'Content-Type: application/x-www-form-urlencoded',
'apiKey: 61449ca078574078a6d0eaaa01cfb751f803797c99714f74d8541a25e2a612ef',
'Accept: application/json'
],
]);
$response = curl_exec($curl);
curl_close($curl);
echo $response;
}
Side note, if you want to "reverse engineer" the data that is in the encoded string in order to build it up in your own code, you can do so with using urldecode and parse_str:
$str = 'username=sandbox&recipients=%5B%7B%22phoneNumber%22%3D%3E%24Recieving_mobile%2C%22amount%22%3D%3E%24Airtime_amount%7D%5D';
parse_str(urldecode($str), $params);
print_r($params);
Result:
Array
(
[username] => sandbox
[recipients] => [{"phoneNumber"=>$Recieving_mobile,"amount"=>$Airtime_amount}]
)