Use of the Access Control System (Revolution)

<?php
class modTest extends modAccessibleSimpleObject {
    public function findPolicy($context = '') {
        $policy = array();
        $context = !empty($context) ? $context : $this->xpdo->context->get('key');
        if (empty($this->_policies) || !isset($this->_policies[$context])) {
            $accessTable = $this->xpdo->getTableName('modAccessTest');
            $policyTable = $this->xpdo->getTableName('modAccessPolicy');
            $sql = "SELECT acl.target, acl.principal, acl.authority, acl.policy, p.data FROM {$accessTable} acl " .
                    "LEFT JOIN {$policyTable} p ON p.id = acl.policy " .
                    "WHERE acl.principal_class = 'modUserGroup' " .
                    "AND acl.target = :test " .
                    "GROUP BY acl.target, acl.principal, acl.authority, acl.policy";
            $bindings = array(
                ':test' => $this->get('id')
            );
            $query = new xPDOCriteria($this->xpdo, $sql, $bindings);
            if ($query->stmt && $query->stmt->execute()) {
                while ($row = $query->stmt->fetch(PDO::FETCH_ASSOC)) {
                    $policy['modAccessTest'][$row['target']][] = array(
                        'principal' => $row['principal'],
                        'authority' => $row['authority'],
                        'policy' => $row['data'] ? xPDO :: fromJSON($row['data'], true) : array(),
                    );
                }
            }
            $this->_policies[$context] = $policy;
        } else {
            $policy = $this->_policies[$context];
        }
        return $policy;
    }
}
?>

 Array
(
    [modx.user.contextTokens] => Array()
    [modx.user..attributes] => Array
        (
            [web] => Array
                (
                    [modAccessContext] => Array()
                    [modAccessResourceGroup] => Array()
                    [modAccessCategory] => Array()
                    [modAccessTest] => Array()
                        (
                            [2] => Array
                                (
                                    [0] => Array
                                        (
                                            [principal] => 0
                                            [authority] => 0
                                            [policy] => Array
                                                (
                                                )
...
        )

    [webDocgroups] => Array()
)

$modx->user->getAttributes('modTest', 'web', true);

$tests = $modx->getCollection('modTest');
foreach ($tests as $test) {
echo $test->get('name')."<br />";
}

<?php
$object = $modx->getObject('ClassName', 3);
if (!$object) {
    // handle error here somehow
    $modx->sendUnauthorizedPage();
}
// code that tries to use the object if it is accessible

<?xml version="1.0" encoding="UTF-8"?>
<model package="hotels" baseClass="xPDOObject" platform="mysql" defaultEngine="MyISAM" tablePrefix="tw_" phpdoc-package="hotels" phpdoc-subpackage="model">

    <object class="modAccessHotels" table="access_hotels" extends="modAccess">
        <aggregate alias="Target" class="modHotels" local="target" foreign="id" owner="foreign" cardinality="one" />
    </object>

    <object class="modHotelsGroup" table="hotel_groups" extends="xPDOSimpleObject">
        <field key="hotels_group" dbtype="int" precision="10" phptype="integer" null="false" default="0" index="index" />
        <field key="hotels" dbtype="int" precision="10" phptype="integer" null="false" default="0" index="index" />        
        <aggregate alias="Hotels" class="modHotels" key="id" local="document" foreign="id" cardinality="one" owner="foreign" />
    </object>

    <object class="modHotels" table="hotels" extends="modAccessibleSimpleObject">
        <field key="name" dbtype="varchar" precision="100" phptype="string" null="false" default="" index="index" />
        <field key="address" dbtype="varchar" precision="255" phptype="string" null="false" default="" />
        <field key="city" dbtype="varchar" precision="255" phptype="string" null="false" default="" />
        <field key="country" dbtype="varchar" precision="20" phptype="string" null="false" default="" />
        <composite alias="HotelsGroup" class="modHotelsGroup" local="id" foreign="hotels" cardinality="many" owner="local" />
        <composite alias="Acls" class="modAccessHotels" local="id" foreign="target" owner="local" cardinality="many" />
    </object>

</model>

<?xml version="1.0" encoding="UTF-8"?>
<model package="hotels" baseClass="xPDOObject" platform="mysql" defaultEngine="MyISAM" tablePrefix="tw_" phpdoc-package="hotels" phpdoc-subpackage="mysql">

    <object class="twAccessHotel" table="access_hotels" extends="modAccess">
        <aggregate alias="Target" class="twHotel" local="target" foreign="id" owner="foreign" cardinality="one" />
    </object>

    <object class="twHotelGroup" table="hotel_groups" extends="xPDOSimpleObject">
        <field key="name" dbtype="varchar" precision="100" phptype="string" null="false" default="" index="unique" />
        <composite alias="Hotels" class="twHotelGroups" local="id" foreign="group" cardinality="many" owner="local" />
    </object>

    <object class="twHotelGroupHotel" table="hotel_group_hotels" extends="xPDOObject">
        <field key="group" dbtype="int" precision="10" phptype="integer" null="false" default="0" index="pk" />
        <field key="hotel" dbtype="int" precision="10" phptype="integer" null="false" default="0" index="pk" />
        <aggregate alias="Group" class="twHotelGroup" local="group" foreign="id" cardinality="one" owner="foreign" />
        <aggregate alias="Hotel" class="twHotel" local="hotel" foreign="id" cardinality="one" owner="foreign" />
    </object>

    <object class="twHotel" table="hotels" extends="modAccessibleSimpleObject">
        <field key="name" dbtype="varchar" precision="100" phptype="string" null="false" default="" index="index" />
        <field key="address" dbtype="varchar" precision="255" phptype="string" null="false" default="" />
        <field key="city" dbtype="varchar" precision="255" phptype="string" null="false" default="" />
        <field key="country" dbtype="varchar" precision="20" phptype="string" null="false" default="" />
        <composite alias="Groups" class="twHotelGroupHotel" local="id" foreign="hotel" cardinality="many" owner="local" />
        <composite alias="Acls" class="twAccessHotel" local="id" foreign="target" owner="local" cardinality="many" />
    </object>

</model>