fulcrm_shoppingcart/fulcrm_shoppingcart.module

<?php

function fulcrm_shoppingcart_permission() {
  return array( 'administer fulcrm shoppingcart' => array( 'title' => t('Administer fulcrm shopping cart'),
                                                           'description' => t('Perform main installation/administration tasks for fulcrm shopping cart.'),
                                                           ),                          
                );
}

function fulcrm_shoppingcart_menu() {
    /*
    $items[ 'admin/config/services/fulcrm' ] = array( 'page callback' => 'system_admin_menu_block_page',
                                                      'file' => 'system.admin.inc',
                                                      'file path' => drupal_get_path('module', 'system'),
                                                      'title' => 'fulcrm',
                                                      'description' => 'Configuration integration with fulcrm.org.',
                                                      'position' => 'right',
                                                      'access callback' => 'user_access',
                                                      'access arguments' => array('access administration pages'),
                                                      );
   */
    $items[ 'admin/config/services/fulcrm/shoppingcart' ] = array( 'page callback' => 'fulcrm_shoppingcart_admin',
                                                                   'file' => 'fulcrm_shoppingcart.admin.inc',
                                                                   'title' => 'fulcrm Shopping Cart',
                                                                   'description' => 'Configure Shopping Cart for fulcrm.org.',
                                                                   'access callback' => 'user_access',
                                                                   'access arguments' => array('administer fulcrm shoppingcart'),
                                                                   );

    $items[ 'fulcrm/buy/%/%' ] = array( 'page callback' => 'fulcrm_shoppingcart_buy',
                                        'page arguments' => array(2,3),
                                        'type' => MENU_CALLBACK,
                                        'access callback' => 'user_access',
                                        'access arguments' => array('access content'),
                                        );
    $items[ 'fulcrm/cart' ] = array( 'page callback' => 'fulcrm_shoppingcart_cart',
                                     'type' => MENU_CALLBACK,
                                     'access callback' => 'user_access',
                                     'access arguments' => array('access content'),
                                     );
    $items[ 'fulcrm/checkout' ] = array( 'page callback' => 'fulcrm_shoppingcart_checkout',
                                         'type' => MENU_CALLBACK,
                                         'access callback' => 'user_access',
                                         'access arguments' => array('access content'),
                                         );

    return $items;
}

function fulcrm_shoppingcart_theme( $existing, $type, $theme, $path ) {
    return array( 'fulcrm_shoppingcart_cart' => array( 'variables' => array( 'shoppingcart' => null ), // data returned from fulcrm API
                                                       'template' => 'fulcrm_shoppingcart_cart',
                                                        ),
                  'fulcrm_shoppingcart_cart_items' => array( 'variables' => array( 'shoppingitems' => null ), // data returned from fulcrm API
                                                             'template' => 'fulcrm_shoppingcart_cart_items',
                                                             ),
                  'fulcrm_shoppingcart_cart_item' => array( 'variables' => array( 'shoppingitem' => null ), // data returned from fulcrm API
                                                            'template' => 'fulcrm_shoppingcart_cart_item',
                                                            ),
                  );
}

function fulcrm_shoppingcart_get_session_cart( $create = true ) {
    global $user;

    drupal_session_start();

    if ( array_key_exists( 'fulcrm_shoppingcart_id', $_SESSION ) ) {
        $api_data = fulcrm_apiv2_GET( 'shoppingcart/' . $_SESSION[ 'fulcrm_shoppingcart_id' ] . '/',
                                      $query = array( 'expand' => implode( ',', array( 'shoppingitems',
                                                                                       'shoppingitems.content_object' ) ) ) );
        if ( $api_data[ 'success' ] ) {
            if ( ( $api_data[ 'data' ][ 'completed' ] === null ) && ( $api_data[ 'data' ][ 'abandoned' ] === null ) ) {
                return $api_data[ 'data' ];
            }
        }
    }

    if ( $create ) {
        $person_url = null;
        if ( !user_is_anonymous() ) {
            $person_id = fulcrm_webhook_get_pk_for_entity_type( 'user', $user->uid, 'person' );

            if ( $person_id )
                $person_url = fulcrm_apiv2_make_url( 'person', $person_id );
        }

        $cart_data = array( 'person' => $person_url, 'd' => array( 'fulcrm_testing_data' => 'this is a test' ) );

        $api_data = fulcrm_apiv2_POST( 'shoppingcart/', $cart_data );
        if ( $api_data[ 'success' ] ) {
            $_SESSION[ 'fulcrm_shoppingcart_id' ] = $api_data[ 'data' ][ 'id' ];
            return $api_data[ 'data' ];
        }
    }
}

function _fulcrm_shoppingcart_buy_hmac( $product_id ) {
    return drupal_hmac_base64( 'fulcrm:' . strval( $product_id ) . ':product_id', session_id() . drupal_get_hash_salt() );
}

function fulcrm_shoppingcart_buy_url( $product_id ) {
    $hmac = _fulcrm_shoppingcart_buy_hmac( $product_id );
    return url( 'fulcrm/buy/' . $product_id . '/' . $hmac );
}

function fulcrm_shoppingcart_buy( $product_id, $hmac ) {
    $real_hmac = _fulcrm_shoppingcart_buy_hmac( $product_id );

    if ( hash_equals( $real_hmac, $hmac ) ) {
        $api_data = fulcrm_apiv2_GET( 'product/' . $product_id . '/',
                                      $query = array( 'expand' => implode( ',', array( 'content_object',
                                                                                       'selector_object',
                                                                                       'person_ddatacollection',
                                                                                       'organisation_ddatacollection',
                                                                                       'thing_ddatacollection',
                                                                                       'transaction_ddatacollection',
                                                                                       'lineitem_ddatacollection',
                                                                                       ) ) ) );

        if ( $api_data[ 'success' ] ) {
            switch ( fulcrm_apiv2_url_to_type( $api_data[ 'data' ][ 'content_object' ][ 'url' ] ) ) {
            case 'eventbookingtype':
                break;
            default:
                return 'cannot handle these products yet';
            }

            return 'ok!';
        } else {
            return 'error adding item to shopping basket';
        }
    } else {
        drupal_not_found();
    }
}

function fulcrm_shoppingcart_cart() {
    $cart = fulcrm_shoppingcart_get_session_cart( false );
    return theme( 'fulcrm_shoppingcart_cart', array( 'cart' => $cart ) );
}

function fulcrm_shoppingcart_checkout() {
    $cart = fulcrm_shoppingcart_get_session_cart( false );
    return print_r( $cart, 1 );
}