Proyectos de Subversion Moodle

<?php

// This file is part of Moodle - http://moodle.org/

//

// Moodle is free software: you can redistribute it and/or modify

// it under the terms of the GNU General Public License as published by

// the Free Software Foundation, either version 3 of the License, or

// (at your option) any later version.

//

// Moodle is distributed in the hope that it will be useful,

// but WITHOUT ANY WARRANTY; without even the implied warranty of

// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

// GNU General Public License for more details.

//

// You should have received a copy of the GNU General Public License

// along with Moodle.  If not, see <http://www.gnu.org/licenses/>.

/**

 * This file contains an abstract definition of an LTI resource

 *

 * @package    mod_lti

 * @copyright  2014 Vital Source Technologies http://vitalsource.com

 * @author     Stephen Vickers

 * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later

 */

namespace mod_lti\local\ltiservice;

defined('MOODLE_INTERNAL') || die();

global $CFG;

require_once($CFG->dirroot . '/mod/lti/locallib.php');

/**

 * The mod_lti\local\ltiservice\resource_base class.

 *

 * @package    mod_lti

 * @since      Moodle 2.8

 * @copyright  2014 Vital Source Technologies http://vitalsource.com

 * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later

 */

abstract class resource_base {

    /**  HTTP Post method */

    const HTTP_POST = 'POST';

    /**  HTTP Get method */

    const HTTP_GET = 'GET';

    /**  HTTP Put method */

    const HTTP_PUT = 'PUT';

    /**  HTTP Delete method */

    const HTTP_DELETE = 'DELETE';

    /** @var service_base Service associated with this resource. */

    private $service;

    /** @var string Type for this resource. */

    protected $type;

    /** @var string ID for this resource. */

    protected $id;

    /** @var string Template for this resource. */

    protected $template;

    /** @var array Custom parameter substitution variables associated with this resource. */

    protected $variables;

    /** @var array Media types supported by this resource. */

    protected $formats;

    /** @var array HTTP actions supported by this resource. */

    protected $methods;

    /** @var array Template variables parsed from the resource template. */

    protected $params;

    /**

     * Class constructor.

     *

     * @param service_base $service Service instance

     */

    public function __construct($service) {

        $this->service = $service;

        $this->type = 'RestService';

        $this->id = null;

        $this->template = null;

        $this->methods = array();

        $this->variables = array();

        $this->formats = array();

        $this->methods = array();

        $this->params = null;

    }

    /**

     * Get the resource ID.

     *

     * @return string

     */

    public function get_id() {

        return $this->id;

    }

    /**

     * Get the resource template.

     *

     * @return string

     */

    public function get_template() {

        return $this->template;

    }

    /**

     * Get the resource path.

     *

     * @return string

     */

    public function get_path() {

        return $this->get_template();

    }

    /**

     * Get the resource type.

     *

     * @return string

     */

    public function get_type() {

        return $this->type;

    }

    /**

     * Get the resource's service.

     *

     * @return service_base

     */

    public function get_service() {

        return $this->service;

    }

    /**

     * Get the resource methods.

     *

     * @return array

     */

    public function get_methods() {

        return $this->methods;

    }

    /**

     * Get the resource media types.

     *

     * @return array

     */

    public function get_formats() {

        return $this->formats;

    }

    /**

     * Get the resource template variables.

     *

     * @return array

     */

    public function get_variables() {

        return $this->variables;

    }

    /**

     * Get the resource fully qualified endpoint.

     *

     * @return string

     */

    public function get_endpoint() {

        $this->parse_template();

        $template = preg_replace('/[\(\)]/', '', $this->get_template());

        $url = $this->get_service()->get_service_path() . $template;

        foreach ($this->params as $key => $value) {

            $url = str_replace('{' . $key . '}', $value, $url);

        }

        $toolproxy = $this->get_service()->get_tool_proxy();

        if (!empty($toolproxy)) {

            $url = str_replace('{config_type}', 'toolproxy', $url);

            $url = str_replace('{tool_proxy_id}', $toolproxy->guid, $url);

        } else {

            $url = str_replace('{config_type}', 'tool', $url);

            $url = str_replace('{tool_proxy_id}', $this->get_service()->get_type()->id, $url);

        }

        return $url;

    }

    /**

     * Execute the request for this resource.

     *

     * @param response $response  Response object for this request.

     */

    abstract public function execute($response);

    /**

     * Check to make sure the request is valid.

     *

     * @param int $typeid                   The typeid we want to use

     * @param string $body                  Body of HTTP request message

     * @param string[] $scopes              Array of scope(s) required for incoming request

     *

     * @return boolean

     */

    public function check_tool($typeid, $body = null, $scopes = null) {

        $ok = $this->get_service()->check_tool($typeid, $body, $scopes);

        if ($ok) {

            if ($this->get_service()->get_tool_proxy()) {

                $toolproxyjson = $this->get_service()->get_tool_proxy()->toolproxy;

            }

            if (!empty($toolproxyjson)) {

                // Check tool proxy to ensure service being requested is included.

                $toolproxy = json_decode($toolproxyjson);

                if (!empty($toolproxy) && isset($toolproxy->security_contract->tool_service)) {

                    $contexts = lti_get_contexts($toolproxy);

                    $tpservices = $toolproxy->security_contract->tool_service;

                    foreach ($tpservices as $service) {

                        $fqid = lti_get_fqid($contexts, $service->service);

                        $id = explode('#', $fqid, 2);

                        if ($this->get_id() === $id[1]) {

                            $ok = true;

                            break;

                        }

                    }

                }

                if (!$ok) {

                    debugging('Requested service not permitted: ' . $this->get_id(), DEBUG_DEVELOPER);

                }

            } else {

                // Check that the scope required for the service request is included in those granted for the

                // access token being used.

                $permittedscopes = $this->get_service()->get_permitted_scopes();

                $ok = is_null($permittedscopes) || empty($scopes) || !empty(array_intersect($permittedscopes, $scopes));

            }

        }

        return $ok;

    }

    /**

     * Check to make sure the request is valid.

     *

     * @param string $toolproxyguid Consumer key

     * @param string $body          Body of HTTP request message

     *

     * @return boolean

     * @deprecated since Moodle 3.7 MDL-62599 - please do not use this function any more.

     * @see resource_base::check_tool()

     */

    public function check_tool_proxy($toolproxyguid, $body = null) {

        debugging('check_tool_proxy() is deprecated to allow LTI 1 connections to support services. ' .

                  'Please use resource_base::check_tool() instead.', DEBUG_DEVELOPER);

        $ok = false;

        if ($this->get_service()->check_tool_proxy($toolproxyguid, $body)) {

            $toolproxyjson = $this->get_service()->get_tool_proxy()->toolproxy;

            if (empty($toolproxyjson)) {

                $ok = true;

            } else {

                $toolproxy = json_decode($toolproxyjson);

                if (!empty($toolproxy) && isset($toolproxy->security_contract->tool_service)) {

                    $contexts = lti_get_contexts($toolproxy);

                    $tpservices = $toolproxy->security_contract->tool_service;

                    foreach ($tpservices as $service) {

                        $fqid = lti_get_fqid($contexts, $service->service);

                        $id = explode('#', $fqid, 2);

                        if ($this->get_id() === $id[1]) {

                            $ok = true;

                            break;

                        }

                    }

                }

                if (!$ok) {

                    debugging('Requested service not included in tool proxy: ' . $this->get_id());

                }

            }

        }

        return $ok;

    }

    /**

     * Check to make sure the request is valid.

     *

     * @param int $typeid                   The typeid we want to use

     * @param int $contextid                The course we are at

     * @param string $permissionrequested   The permission to be checked

     * @param string $body                  Body of HTTP request message

     *

     * @return boolean

     * @deprecated since Moodle 3.7 MDL-62599 - please do not use this function any more.

     * @see resource_base::check_tool()

     */

    public function check_type($typeid, $contextid, $permissionrequested, $body = null) {

        debugging('check_type() is deprecated to allow LTI 1 connections to support services. ' .

                  'Please use resource_base::check_tool() instead.', DEBUG_DEVELOPER);

        $ok = false;

        if ($this->get_service()->check_type($typeid, $contextid, $body)) {

            $neededpermissions = $this->get_permissions($typeid);

            foreach ($neededpermissions as $permission) {

                if ($permission == $permissionrequested) {

                    $ok = true;

                    break;

                }

            }

            if (!$ok) {

                debugging('Requested service ' . $permissionrequested . ' not included in tool type: ' . $typeid,

                    DEBUG_DEVELOPER);

            }

        }

        return $ok;

    }

    /**

     * get permissions from the config of the tool for that resource

     *

     * @param int $ltitype Type of LTI

     * @return array with the permissions related to this resource by the $ltitype or empty if none.

     * @deprecated since Moodle 3.7 MDL-62599 - please do not use this function any more.

     * @see resource_base::check_tool()

     */

    public function get_permissions($ltitype) {

        debugging('get_permissions() is deprecated to allow LTI 1 connections to support services. ' .

                  'Please use resource_base::check_tool() instead.', DEBUG_DEVELOPER);

        return array();

    }

    /**

     * Parse a value for custom parameter substitution variables.

     *

     * @param string $value String to be parsed

     *

     * @return string

     */

    public function parse_value($value) {

        return $value;

    }

    /**

     * Parse the template for variables.

     *

     * @return array

     */

    protected function parse_template() {

        if (empty($this->params)) {

            $this->params = array();

            if (!empty($_SERVER['PATH_INFO'])) {

                $path = explode('/', $_SERVER['PATH_INFO']);

                $template = preg_replace('/\([0-9a-zA-Z_\-,\/]+\)/', '', $this->get_template());

                $parts = explode('/', $template);

                for ($i = 0; $i < count($parts); $i++) {

                    if ((substr($parts[$i], 0, 1) == '{') && (substr($parts[$i], -1) == '}')) {

                        $value = '';

                        if ($i < count($path)) {

                            $value = $path[$i];

                        }

                        $this->params[substr($parts[$i], 1, -1)] = $value;

                    }

                }

            }

        }

        return $this->params;

    }

}