Proyectos de Subversion Moodle

<?php

namespace IMSGlobal\LTI\ToolProvider\DataConnector;

use IMSGlobal\LTI\ToolProvider\ConsumerNonce;

use IMSGlobal\LTI\ToolProvider\Context;

use IMSGlobal\LTI\ToolProvider\ResourceLink;

use IMSGlobal\LTI\ToolProvider\ResourceLinkShareKey;

use IMSGlobal\LTI\ToolProvider\ToolConsumer;

use IMSGlobal\LTI\ToolProvider\ToolProxy;

use IMSGlobal\LTI\ToolProvider\User;

use PDO;

/**

 * Class to provide a connection to a persistent store for LTI objects

 *

 * This class assumes no data persistence - it should be extended for specific database connections.

 *

 * @author  Stephen P Vickers <svickers@imsglobal.org>

 * @copyright  IMS Global Learning Consortium Inc

 * @date  2016

 * @version 3.0.0

 * @license http://www.apache.org/licenses/LICENSE-2.0 Apache License, Version 2.0

 */

#[\AllowDynamicProperties]

class DataConnector

{

/**

 * Default name for database table used to store tool consumers.

 */

    const CONSUMER_TABLE_NAME = 'lti2_consumer';

/**

 * Default name for database table used to store pending tool proxies.

 */

    const TOOL_PROXY_TABLE_NAME = 'lti2_tool_proxy';

/**

 * Default name for database table used to store contexts.

 */

    const CONTEXT_TABLE_NAME = 'lti2_context';

/**

 * Default name for database table used to store resource links.

 */

    const RESOURCE_LINK_TABLE_NAME = 'lti2_resource_link';

/**

 * Default name for database table used to store users.

 */

    const USER_RESULT_TABLE_NAME = 'lti2_user_result';

/**

 * Default name for database table used to store resource link share keys.

 */

    const RESOURCE_LINK_SHARE_KEY_TABLE_NAME = 'lti2_share_key';

/**

 * Default name for database table used to store nonce values.

 */

    const NONCE_TABLE_NAME = 'lti2_nonce';

/**

 * Database object.

 *

 * @var object $db

 */

    protected $db = null;

/**

 * Prefix for database table names.

 *

 * @var string $dbTableNamePrefix

 */

    protected $dbTableNamePrefix = '';

/**

 * SQL date format (default = 'Y-m-d')

 *

 * @var string $dateFormat

 */

    protected $dateFormat = 'Y-m-d';

/**

 * SQL time format (default = 'H:i:s')

 *

 * @var string $timeFormat

 */

    protected $timeFormat = 'H:i:s';

/**

 * Class constructor

 *

 * @param object $db                 Database connection object

 * @param string $dbTableNamePrefix  Prefix for database table names (optional, default is none)

 */

    public function __construct($db, $dbTableNamePrefix = '')

    {

        $this->db = $db;

        $this->dbTableNamePrefix = $dbTableNamePrefix;

    }

###

###  ToolConsumer methods

###

/**

 * Load tool consumer object.

 *

 * @param ToolConsumer $consumer ToolConsumer object

 *

 * @return boolean True if the tool consumer object was successfully loaded

 */

    public function loadToolConsumer($consumer)

    {

        $consumer->secret = 'secret';

        $consumer->enabled = true;

        $now = time();

        $consumer->created = $now;

        $consumer->updated = $now;

        return true;

    }

/**

 * Save tool consumer object.

 *

 * @param ToolConsumer $consumer Consumer object

 *

 * @return boolean True if the tool consumer object was successfully saved

 */

    public function saveToolConsumer($consumer)

    {

        $consumer->updated = time();

        return true;

    }

/**

 * Delete tool consumer object.

 *

 * @param ToolConsumer $consumer Consumer object

 *

 * @return boolean True if the tool consumer object was successfully deleted

 */

    public function deleteToolConsumer($consumer)

    {

        $consumer->initialize();

        return true;

    }

/**

 * Load tool consumer objects.

 *

 * @return array Array of all defined ToolConsumer objects

 */

    public function getToolConsumers()

    {

        return array();

    }

###

###  ToolProxy methods

###

/**

 * Load tool proxy object.

 *

 * @param ToolProxy $toolProxy ToolProxy object

 *

 * @return boolean True if the tool proxy object was successfully loaded

 */

    public function loadToolProxy($toolProxy)

    {

        $now = time();

        $toolProxy->created = $now;

        $toolProxy->updated = $now;

        return true;

    }

/**

 * Save tool proxy object.

 *

 * @param ToolProxy $toolProxy ToolProxy object

 *

 * @return boolean True if the tool proxy object was successfully saved

 */

    public function saveToolProxy($toolProxy)

    {

        $toolProxy->updated = time();

        return true;

    }

/**

 * Delete tool proxy object.

 *

 * @param ToolProxy $toolProxy ToolProxy object

 *

 * @return boolean True if the tool proxy object was successfully deleted

 */

    public function deleteToolProxy($toolProxy)

    {

        $toolProxy->initialize();

        return true;

    }

###

###  Context methods

###

/**

 * Load context object.

 *

 * @param Context $context Context object

 *

 * @return boolean True if the context object was successfully loaded

 */

    public function loadContext($context)

    {

        $now = time();

        $context->created = $now;

        $context->updated = $now;

        return true;

    }

/**

 * Save context object.

 *

 * @param Context $context Context object

 *

 * @return boolean True if the context object was successfully saved

 */

    public function saveContext($context)

    {

        $context->updated = time();

        return true;

    }

/**

 * Delete context object.

 *

 * @param Context $context Context object

 *

 * @return boolean True if the Context object was successfully deleted

 */

    public function deleteContext($context)

    {

        $context->initialize();

        return true;

    }

###

###  ResourceLink methods

###

/**

 * Load resource link object.

 *

 * @param ResourceLink $resourceLink Resource_Link object

 *

 * @return boolean True if the resource link object was successfully loaded

 */

    public function loadResourceLink($resourceLink)

    {

        $now = time();

        $resourceLink->created = $now;

        $resourceLink->updated = $now;

        return true;

    }

/**

 * Save resource link object.

 *

 * @param ResourceLink $resourceLink Resource_Link object

 *

 * @return boolean True if the resource link object was successfully saved

 */

    public function saveResourceLink($resourceLink)

    {

        $resourceLink->updated = time();

        return true;

    }

/**

 * Delete resource link object.

 *

 * @param ResourceLink $resourceLink Resource_Link object

 *

 * @return boolean True if the resource link object was successfully deleted

 */

    public function deleteResourceLink($resourceLink)

    {

        $resourceLink->initialize();

        return true;

    }

/**

 * Get array of user objects.

 *

 * Obtain an array of User objects for users with a result sourcedId.  The array may include users from other

 * resource links which are sharing this resource link.  It may also be optionally indexed by the user ID of a specified scope.

 *

 * @param ResourceLink $resourceLink      Resource link object

 * @param boolean     $localOnly True if only users within the resource link are to be returned (excluding users sharing this resource link)

 * @param int         $idScope     Scope value to use for user IDs

 *

 * @return array Array of User objects

 */

    public function getUserResultSourcedIDsResourceLink($resourceLink, $localOnly, $idScope)

    {

        return array();

    }

/**

 * Get array of shares defined for this resource link.

 *

 * @param ResourceLink $resourceLink Resource_Link object

 *

 * @return array Array of ResourceLinkShare objects

 */

    public function getSharesResourceLink($resourceLink)

    {

        return array();

    }

###

###  ConsumerNonce methods

###

/**

 * Load nonce object.

 *

 * @param ConsumerNonce $nonce Nonce object

 *

 * @return boolean True if the nonce object was successfully loaded

 */

    public function loadConsumerNonce($nonce)

    {

        return false;  // assume the nonce does not already exist

    }

/**

 * Save nonce object.

 *

 * @param ConsumerNonce $nonce Nonce object

 *

 * @return boolean True if the nonce object was successfully saved

 */

    public function saveConsumerNonce($nonce)

    {

        return true;

    }

###

###  ResourceLinkShareKey methods

###

/**

 * Load resource link share key object.

 *

 * @param ResourceLinkShareKey $shareKey Resource_Link share key object

 *

 * @return boolean True if the resource link share key object was successfully loaded

 */

    public function loadResourceLinkShareKey($shareKey)

    {

        return true;

    }

/**

 * Save resource link share key object.

 *

 * @param ResourceLinkShareKey $shareKey Resource link share key object

 *

 * @return boolean True if the resource link share key object was successfully saved

 */

    public function saveResourceLinkShareKey($shareKey)

    {

        return true;

    }

/**

 * Delete resource link share key object.

 *

 * @param ResourceLinkShareKey $shareKey Resource link share key object

 *

 * @return boolean True if the resource link share key object was successfully deleted

 */

    public function deleteResourceLinkShareKey($shareKey)

    {

        return true;

    }

###

###  User methods

###

/**

 * Load user object.

 *

 * @param User $user User object

 *

 * @return boolean True if the user object was successfully loaded

 */

    public function loadUser($user)

    {

        $now = time();

        $user->created = $now;

        $user->updated = $now;

        return true;

    }

/**

 * Save user object.

 *

 * @param User $user User object

 *

 * @return boolean True if the user object was successfully saved

 */

    public function saveUser($user)

    {

        $user->updated = time();

        return true;

    }

/**

 * Delete user object.

 *

 * @param User $user User object

 *

 * @return boolean True if the user object was successfully deleted

 */

    public function deleteUser($user)

    {

        $user->initialize();

        return true;

    }

###

###  Other methods

###

/**

 * Return a hash of a consumer key for values longer than 255 characters.

 *

 * @param string $key

 * @return string

 */

    protected static function getConsumerKey($key)

    {

        $len = strlen($key);

        if ($len > 255) {

            $key = 'sha512:' . hash('sha512', $key);

        }

        return $key;

    }

/**

 * Create data connector object.

 *

 * A data connector provides access to persistent storage for the different objects.

 *

 * Names of tables may be given a prefix to allow multiple versions to share the same schema.  A separate sub-class is defined for

 * each different database connection - the class to use is determined by inspecting the database object passed, but this can be overridden

 * (for example, to use a bespoke connector) by specifying a type.  If no database is passed then this class is used which acts as a dummy

 * connector with no persistence.

 *

 * @param string  $dbTableNamePrefix  Prefix for database table names (optional, default is none)

 * @param object  $db                 A database connection object or string (optional, default is no persistence)

 * @param string  $type               The type of data connector (optional, default is based on $db parameter)

 *

 * @return DataConnector Data connector object

 */

    public static function getDataConnector($dbTableNamePrefix = '', $db = null, $type = '')

    {

        if (is_null($dbTableNamePrefix)) {

            $dbTableNamePrefix = '';

        }

        if (!is_null($db) && empty($type)) {

            if (is_object($db)) {

                $type = get_class($db);

            }

        }

        $type = strtolower($type);

        if (($type === 'pdo') && ($db->getAttribute(PDO::ATTR_DRIVER_NAME) === 'sqlite')) {

            $type .= '_sqlite';

        }

        if (!empty($type)) {

            $type ="DataConnector_{$type}";

        } else {

            $type ='DataConnector';

        }

        $type = "\\IMSGlobal\\LTI\\ToolProvider\\DataConnector\\{$type}";

        $dataConnector = new $type($db, $dbTableNamePrefix);

        return $dataConnector;

    }

/**

 * Generate a random string.

 *

 * The generated string will only comprise letters (upper- and lower-case) and digits.

 *

 * @param int $length Length of string to be generated (optional, default is 8 characters)

 *

 * @return string Random string

 */

    static function getRandomString($length = 8)

    {

        $chars = 'ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789';

        $value = '';

        $charsLength = strlen($chars) - 1;

        for ($i = 1 ; $i <= $length; $i++) {

            $value .= $chars[rand(0, $charsLength)];

        }

        return $value;

    }

/**

 * Quote a string for use in a database query.

 *

 * Any single quotes in the value passed will be replaced with two single quotes.  If a null value is passed, a string

 * of 'null' is returned (which will never be enclosed in quotes irrespective of the value of the $addQuotes parameter.

 *

 * @param string $value Value to be quoted

 * @param bool $addQuotes If true the returned string will be enclosed in single quotes (optional, default is true)

 * @return string The quoted string.

 */

    static function quoted($value, $addQuotes = true)

    {

        if (is_null($value)) {

            $value = 'null';

        } else {

            $value = str_replace('\'', '\'\'', $value);

            if ($addQuotes) {

                $value = "'{$value}'";

            }

        }

        return $value;

    }

}