index.php

<?php

// Callback Function For POST REQUEST
function wp_webhook_rest_api_post_response($request) {

$parameters = $request->get_params();

    //sample input data
//$parameters = array(0=> array("ParticipationId"=>"E12E5A02-152F-48BB-B907-758C91C2855",
//         "ParticipantId"=>"8766979878979879797",
//         "PIIDataId"=>"8766979878979879797",
//         "InstantWinSlotId"=>"8766979878979879797",
//         "PackCode"=>"N3YQW7F7",
//         "WinId"=>"hUty7",
//         "Email"=>"encoding.test3@some.cc",
//         "PrizeName"=>"Hoodie",
//         "Tier"=>"2",
//         "ConfirmationLink"=>"https://any/test",
//         "DrawPeriod"=>"DAILY",
//         "ParticipationDate"=>"2018-03-14 17:06:00",
//         "IsWinConfirmed"=>"false",
//         "Salutation"=>"",
//         "FirstName"=>"Николай2",
//         "LastName"=>"Иванов2",
//         "AddressLine1"=>"",
//         "AddressLine2"=>"",
//         "ZipCode"=>"",
//         "PhoneNumber"=>"687989890",
//         "City"=>"",
//         "DateOfBirth"=>"",
//         "OreojiNumber"=>"",
//         "Gender"=>"",
//         "Size"=>"",
//         "ConfirmationDate"=>""));

    $csvFileName = 'csvFile.csv';
    $mode = file_exists($csvFileName) ? 'a' : 'w';
    $tableHeaders = getHeaders($parameters);

    try {
        $output = fopen($csvFileName, $mode);
        if (!$output) {
            throw new Exception('Unable to open file' . $csvFileName);
        }
        if ($mode == 'w') {
            fputcsv($output, $tableHeaders);
        }

        if (ismulti($parameters)) {
            foreach ($parameters as $val) {
                $outputstring = getstring($val);
                fputcsv($output, $outputstring);
            }
        } else {
            $outputstring = getstring($parameters);
            fputcsv($output, $outputstring);
        }
        //Finally, close the file pointer.
        fclose($output);
    } catch (Exception $ex) {
        throw new Exception('There was an error writing output to the file');
    }
    
    $success = array('status'=>'success');
    header('Content-Type: application/json');
    return json_encode($success);
}

/**
 *  Returns One dimensional array to be printed in the csv file
 * @param array $val
 * @return array
 */
function getstring($val) {

    $string[] = isset($val['ParticipationId']) ? $val['ParticipationId'] : '';
    $string[] = isset($val['ParticipantId']) ? $val['ParticipantId'] : '';
    $string[] = isset($val['PIIDataId']) ? $val['PIIDataId'] : '';
    $string[] = isset($val['InstantWinSlotId']) ? $val['InstantWinSlotId'] : '';
    $string[] = isset($val['PackCode']) ? $val['PackCode'] : '';
    $string[] = isset($val['WinId']) ? $val['WinId'] : '';
    $string[] = isset($val['Email']) ? $val['Email'] : '';
    $string[] = isset($val['PrizeName']) ? $val['PrizeName'] : '';
    $string[] = isset($val['Tier']) ? $val['Tier'] : '';
    $string[] = isset($val['ConfirmationLink']) ? $val['ConfirmationLink'] : '';
    $string[] = isset($val['DrawPeriod']) ? $val['DrawPeriod'] : '';
    $string[] = isset($val['ParticipationDate']) ? $val['ParticipationDate'] : '';
    $string[] = isset($val['IsWinConfirmed']) ? $val['IsWinConfirmed'] : '';
    $string[] = isset($val['Salutation']) ? $val['Salutation'] : '';
    $string[] = isset($val['FirstName']) ? $val['FirstName'] : '';
    $string[] = isset($val['LastName']) ? $val['LastName'] : '';
    $string[] = isset($val['AddressLine1']) ? $val['AddressLine1'] : '';
    $string[] = isset($val['AddressLine2']) ? $val['AddressLine2'] : '';
    $string[] = isset($val['ZipCode']) ? $val['ZipCode'] : '';
    $string[] = isset($val['PhoneNumber']) ? $val['PhoneNumber'] : '';
    $string[] = isset($val['City']) ? $val['City'] : '';
    $string[] = isset($val['DateOfBirth']) ? $val['DateOfBirth'] : '';
    $string[] = isset($val['OreojiNumber']) ? $val['OreojiNumber'] : '';
    $string[] = isset($val['Gender']) ? $val['Gender'] : '';
    $string[] = isset($val['Size']) ? $val['Size'] : '';
    $string[] = isset($val['ConfirmationDate']) ? $val['ConfirmationDate'] : '';

    return $string;
}

/**
 * Returns table headers as one dimensional array
 * 
 * @param array $params
 * @return array
 */
function getHeaders($params) {
    
    if(ismulti($params)){
        $headerarray = $params[0];
       
    }else{
        $headerarray = $params;
    }
    $tableHeaders = array_keys($headerarray);  
    return $tableHeaders;
}

/**
 * Returns if it is multi dimensional array or not
 * @param type $params
 * @return boolean
 */
function ismulti($params){
    if(isset($params[0]) && is_array($params[0])){
        return true;
    }
    return false;
}

//wp_webhook_rest_api_post_response($_REQUEST);