elhardoum/charge.php

## charge.php
<?php

// prevent direct access, only index.php can include this file
defined ( 'STRIPE_SECRET_KEY' ) || exit ( 'Direct access not allowed' . PHP_EOL );

use \Stripe\Stripe;
use \Stripe\Customer;
use \Stripe\Charge;

Stripe::setApiKey(STRIPE_SECRET_KEY);

$token  = isset($_POST['stripeToken']) ? $_POST['stripeToken'] : null;
unset($_POST);

if ( !$token ) {
    return; // just in case
}

try {
    $customer = Customer::create(array(
        'email' => USER_EMAIL,
        'source'  => $token
    ));
} catch ( \Exception $e ) {
    $error []= "Error registering your payment request. Please try again or later!";

    return;
}

try {
    $charge = Charge::create(array(
        'customer' => $customer->id,
        'amount'   => STRIPE_PRICE,
        'currency' => CURRENCY_CODE
    ));
} catch ( Exception $e ) {
    error_log( sprintf('ERROR: Stripe failed for user %s @%d (ip:%s)', USER_EMAIL, time(), $_SERVER['REMOTE_ADDR']) );
    error_log( print_r( $e, true ) );

    $error []= "Error verifying your payment request. Please try again or later if you are sure no payment has been made yet";
    return;
}

// Now we're dealing with a verified payment! Let's upgrade the user!

// a success notice
$success []= "Your payment has been verified successfully! We're upgrading your membership.";

if ( function_exists('upgrade_user') ) {
    $upgraded = upgrade_user(USER_EMAIL);

    if ( !$upgraded ) {
        $error []= "We could not upgrade your membership. Please sit tight as we do it manually";

        error_log( sprintf('Upgrade user %s failed, do it manually ASAP!!', USER_EMAIL) );
    }
}

## index.php
<?php

error_reporting(E_ALL);
ini_set('display_errors', 1);

require __DIR__ . '/vendor/autoload.php';

// API public key
define ( 'STRIPE_PUBLIC_KEY', 'pk_test_6pRNASCoBOKtIshFeQd4XMUh' );

// API secret key
define ( 'STRIPE_SECRET_KEY', 'sk_test_BQokikJOvBiI2HlWgH4olfQ2' );

// stripe amount
define ( 'STRIPE_PRICE', 100 ); // that's $1

// amount currency
define ( 'CURRENCY_CODE', 'USD' );

// current user email
define ( 'USER_EMAIL', 'me@myself.ie' );

$success = $error = array();

// if the form was submitted (i.e payment request sent)
if ( isset($_GET['charge']) && $_POST ) {
    require __DIR__ . '/charge.php';
}

// start output
?>

<!DOCTYPE html>
<html>
<head>
    <title>My Amazing Membership Site</title>
</head>
<body style="background: #ececec; display: table; margin: 0 auto; padding-top: 5vw">

<form action="index.php?charge=1" method="POST">
    <?php if ( $success ) : ?>
        <ul style="background: #d3f1d3; display: block; padding: 1em; border: 1px solid #ddd; border-radius: 3px;">
            <li><?php echo implode ( '</li><li>', $success ); ?></li>
        </ul>
    <?php endif; ?>

    <?php if ( $error ) : ?>
        <ul style="background: #fec8b7; display: block; padding: 1em; border: 1px solid #ddd; border-radius: 3px;">
            <li><?php echo implode ( '</li><li>', $error ); ?></li>
        </ul>
    <?php endif; ?>

    <h3>Pay membership with credit/debit card</h3>

    <p>This is a one-time payment. You will be prompted to enter your card details securly.</p>

    <script
      src="https://checkout.stripe.com/checkout.js" class="stripe-button"
      data-key="<?php echo STRIPE_PUBLIC_KEY; ?>"
      data-email="<?php echo USER_EMAIL; ?>"
      data-amount="<?php echo STRIPE_PRICE; ?>"
      data-name="My Amazing Site"
      data-description="Premium Membership / For Life!"
      data-image="http://lorempixel.com/150/100/cats/"
      data-currency="<?php echo CURRENCY_CODE; ?>"
      data-locale="auto">
    </script>
</form>

</body>
</html>
	<?php

	// prevent direct access, only index.php can include this file
	defined ( 'STRIPE_SECRET_KEY' ) \|\| exit ( 'Direct access not allowed' . PHP_EOL );

	use \Stripe\Stripe;
	use \Stripe\Customer;
	use \Stripe\Charge;

	Stripe::setApiKey(STRIPE_SECRET_KEY);

	$token = isset($_POST['stripeToken']) ? $_POST['stripeToken'] : null;
	unset($_POST);

	if ( !$token ) {
	return; // just in case
	}

	try {
	$customer = Customer::create(array(
	'email' => USER_EMAIL,
	'source' => $token
	));
	} catch ( \Exception $e ) {
	$error []= "Error registering your payment request. Please try again or later!";

	return;
	}

	try {
	$charge = Charge::create(array(
	'customer' => $customer->id,
	'amount' => STRIPE_PRICE,
	'currency' => CURRENCY_CODE
	));
	} catch ( Exception $e ) {
	error_log( sprintf('ERROR: Stripe failed for user %s @%d (ip:%s)', USER_EMAIL, time(), $_SERVER['REMOTE_ADDR']) );
	error_log( print_r( $e, true ) );

	$error []= "Error verifying your payment request. Please try again or later if you are sure no payment has been made yet";
	return;
	}

	// Now we're dealing with a verified payment! Let's upgrade the user!

	// a success notice
	$success []= "Your payment has been verified successfully! We're upgrading your membership.";

	if ( function_exists('upgrade_user') ) {
	$upgraded = upgrade_user(USER_EMAIL);

	if ( !$upgraded ) {
	$error []= "We could not upgrade your membership. Please sit tight as we do it manually";

	error_log( sprintf('Upgrade user %s failed, do it manually ASAP!!', USER_EMAIL) );
	}
	}
	<?php

	error_reporting(E_ALL);
	ini_set('display_errors', 1);

	require __DIR__ . '/vendor/autoload.php';

	// API public key
	define ( 'STRIPE_PUBLIC_KEY', 'pk_test_6pRNASCoBOKtIshFeQd4XMUh' );

	// API secret key
	define ( 'STRIPE_SECRET_KEY', 'sk_test_BQokikJOvBiI2HlWgH4olfQ2' );

	// stripe amount
	define ( 'STRIPE_PRICE', 100 ); // that's $1

	// amount currency
	define ( 'CURRENCY_CODE', 'USD' );

	// current user email
	define ( 'USER_EMAIL', 'me@myself.ie' );

	$success = $error = array();

	// if the form was submitted (i.e payment request sent)
	if ( isset($_GET['charge']) && $_POST ) {
	require __DIR__ . '/charge.php';
	}

	// start output
	?>

	<!DOCTYPE html>
	<html>
	<head>
	<title>My Amazing Membership Site</title>
	</head>
	<body style="background: #ececec; display: table; margin: 0 auto; padding-top: 5vw">

	<form action="index.php?charge=1" method="POST">
	<?php if ( $success ) : ?>
	<ul style="background: #d3f1d3; display: block; padding: 1em; border: 1px solid #ddd; border-radius: 3px;">
	<li><?php echo implode ( '</li><li>', $success ); ?></li>
	</ul>
	<?php endif; ?>

	<?php if ( $error ) : ?>
	<ul style="background: #fec8b7; display: block; padding: 1em; border: 1px solid #ddd; border-radius: 3px;">
	<li><?php echo implode ( '</li><li>', $error ); ?></li>
	</ul>
	<?php endif; ?>

	<h3>Pay membership with credit/debit card</h3>

	<p>This is a one-time payment. You will be prompted to enter your card details securly.</p>

	<script
	src="https://checkout.stripe.com/checkout.js" class="stripe-button"
	data-key="<?php echo STRIPE_PUBLIC_KEY; ?>"
	data-email="<?php echo USER_EMAIL; ?>"
	data-amount="<?php echo STRIPE_PRICE; ?>"
	data-name="My Amazing Site"
	data-description="Premium Membership / For Life!"
	data-image="http://lorempixel.com/150/100/cats/"
	data-currency="<?php echo CURRENCY_CODE; ?>"
	data-locale="auto">
	</script>
	</form>

	</body>
	</html>