Getting started with the GoCardless PHP library

{
  "require": {
    "gocardless/gocardless": ">=0.4.2"
  }
}

<?php
  include_once("lib/GoCardless.php");

  // By default, your application will run in the sandbox - here,
  // you can test with no money changing hands. When you're
  // reading to go live, simply uncomment this line.
  // GoCardless::$environment = 'production';

  // Let's add your authentication details for the production and
  // sandbox. You can get them both from your Dashboard - copy them
  // in to replace the examples.
  if (GoCardless::$environment == 'production') {
    $account_details = array(
      'app_id'        => 'INSERT_LIVE_APP_ID',
      'app_secret'    => 'INSERT_LIVE_APP_SECRET',
      'merchant_id'   => 'INSERT_LIVE_MERCHANT_ID',
      'access_token'  => 'INSERT_LIVE_MERCHANT_ACCESS_TOKEN'
    );
  } else {
    $account_details = array(
      'app_id'        => 'INSERT_SANDBOX_APP_ID',
      'app_secret'    => 'INSERT_SANDBOX_APP_SECRET',
      'merchant_id'   => 'INSERT_SANDBOX_MERCHANT_ID',
      'access_token'  => 'INSERT_SANDBOX_MERCHANT_ACCESS_TOKEN'
    );
  }

  GoCardless::set_account_details($account_details);
?>

<?php
// Bring in the file we made earlier, which includes the GoCardless
// library and all of our configuration
include_once("gocardless.inc.php");

// Provide the details to use to set up the Direct Debit. In
// particular, make sure you set the amount to be higher than
// you'll ever need to collect in a month.
$pre_authorization_details = array(
  "amount" => "10000",
  "interval_length" => 1,
  "interval_unit" => "month"
);

// The GoCardless library puts everything together and
// generates a personalised link to our secure payment pages
$pre_authorization_url = GoCardless::new_pre_authorization_url($pre_authorization_details);

// Now we could put that generated URL behind a link...
echo "<a href='" . $pre_authorization_url . "'>Set up a Direct Debit</a>";
// or we could redirect the user right away...
header("Location: " . $pre_authorization_url);
?>

<?php
// Let's include our central configuration file again.
include_once("gocardless.inc.php");

// Pull out the required data from the redirect
$confirm_params = array(
  'resource_id'    => $_GET['resource_id'],
  'resource_type'  => $_GET['resource_type'],
  'resource_uri'   => $_GET['resource_uri'],
  'signature'      => $_GET['signature']
);

// We'll add this - it'll come into effect if you implement
// a more advanced integration,
if (isset($_GET['state'])) {
  $confirm_params['state'] = $_GET['state'];
}

GoCardless::confirm_resource($confirm_params);

// If all has gone well, you'll now be able to charge this
// customer. To do this, you'll need to store their
// pre-authorization's ID somewhere - for instance on a
// user's database record.
$pre_authorization_id = $resource_id;
?>

<p><b>Thank you!</b></p>

<?php
include_once("gocardless.inc.php");

// You'll need to pull our the customer's pre-
// authorization ID which you saved somewhere in
// the previous step.
$pre_authorization_id = fetch_id_from_database();

$pre_auth = GoCardless_PreAuthorization::find($pre_authorization_id);

// Set the details for the payment to collect. We'll
// display the "name" in emails sent to the customer.
$bill_details = array(
  "name" => "Invoice for June 2014",
  "amount" => "25.00"
);

$bill = $pre_auth->create_bill($bill_details);

// It's likely that you'll want to store the bill's ID
// - this is useful for staying up to date on its status
// later.
$bill_id = $bill->id;
?>