Basic Stripe Checkout example

basic-stripe-example.php

<?php
  
  /*
    Class set initialisation etc
    Include stripe-php/init.php
    .
    .
    .
  */
  
  public static function charge_card() { 

    // token is set in class initialisation
    // basic WordPress nonce check - prevents reload
    if ( self::$token && wp_verify_nonce( $_POST['treat-nonce'], 'charge_card' ) ) {
      
      // Get the credit card details submitted by the form
      // ..
      
      // Data validation
      // ..
      
      // Set secret key for correct environment
      // ..

      // Create new customer (Optional)
      $new_customer = \Stripe\Customer::create( [
        'email' => $_POST['stripeEmail'],
        'card'  => $token,
      ] );

      // Create the charge on Stripe's servers - this will charge the user's default card
      try {
        
        $charge = \Stripe\Charge::create( [
          'amount'      => $amount,             // amount in pence, again
          'currency'    => $currency,           // eg GBP
          'customer'    => $new_customer['id'], // if you created customer above
          'description' => $description,        // order title
          'metadata'    => $meta,               // array of custom fields
        ] );

        // Add Stripe charge ID to querystring.
        // From https://developer.wordpress.org/reference/functions/add_query_arg/:
        $query_args = [
          'charge'  => $charge->id,
          'venue'   => rawurlencode( $venue ),  // Data to be passed to success page (as GET variable)
        ];


      } catch( \Stripe\Error\Card $e ) {

        // There was an error in creating the charge
        $e = $e->getJsonBody();

        // Add failure indicator to querystring.
        $query_args = [
          'charge'        => $e['error']['charge'],
          'charge_failed' => true,
        ];

      }

      unset( $_POST['stripeToken'] );
      self::$token = false;

      // Redirect user to success page (or error page)
      $redirect_url = esc_url_raw( add_query_arg( $query_args, $redirect ) );
      wp_redirect( $redirect_url );
      exit;
    }
  }
  
  /*
    Other utitlity functions, etc
    .
    .
    .
  */