MDL-52035 enrol_lti: added enrol plugin

enrol/lti/classes/helper.php

@@ -0,0 +1,372 @@
+<?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/>.
+
+/**
+ * LTI enrolment plugin helper.
+ *
+ * @package enrol_lti
+ * @copyright 2016 Mark Nelson <markn@moodle.com>
+ * @license http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
+ */
+
+namespace enrol_lti;
+
+defined('MOODLE_INTERNAL') || die();
+
+/**
+ * LTI enrolment plugin helper class.
+ *
+ * @package enrol_lti
+ * @copyright 2016 Mark Nelson <markn@moodle.com>
+ * @license http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
+ */
+class helper {
+    /*
+     * The value used when we want to enrol new members and unenrol old ones.
+     */
+    const MEMBER_SYNC_ENROL_AND_UNENROL = 1;
+
+    /*
+     * The value used when we want to enrol new members only.
+     */
+    const MEMBER_SYNC_ENROL_NEW = 2;
+
+    /*
+     * The value used when we want to unenrol missing users.
+     */
+    const MEMBER_SYNC_UNENROL_MISSING = 3;
+
+    /**
+     * Code for when an enrolment was successful.
+     */
+    const ENROLMENT_SUCCESSFUL = true;
+
+    /**
+     * Error code for enrolment when max enrolled reached.
+     */
+    const ENROLMENT_MAX_ENROLLED = 'maxenrolledreached';
+
+    /**
+     * Error code for enrolment has not started.
+     */
+    const ENROLMENT_NOT_STARTED = 'enrolmentnotstarted';
+
+    /**
+     * Error code for enrolment when enrolment has finished.
+     */
+    const ENROLMENT_FINISHED = 'enrolmentfinished';
+
+    /**
+     * Error code for when an image file fails to upload.
+     */
+    const PROFILE_IMAGE_UPDATE_SUCCESSFUL = true;
+
+    /**
+     * Error code for when an image file fails to upload.
+     */
+    const PROFILE_IMAGE_UPDATE_FAILED = 'profileimagefailed';
+
+    /**
+     * Creates a unique username.
+     *
+     * @param string $consumerkey Consumer key
+     * @param string $ltiuserid External tool user id
+     * @return string The new username
+     */
+    public static function create_username($consumerkey, $ltiuserid) {
+        if (!empty($ltiuserid) && !empty($consumerkey)) {
+            $userkey = $consumerkey . ':' . $ltiuserid;
+        } else {
+            $userkey = false;
+        }
+
+        return 'enrol_lti' . sha1($consumerkey . '::' . $userkey);
+    }
+
+    /**
+     * Adds default values for the user object based on the tool provided.
+     *
+     * @param \stdClass $tool
+     * @param \stdClass $user
+     * @return \stdClass The $user class with added default values
+     */
+    public static function assign_user_tool_data($tool, $user) {
+        global $CFG;
+
+        $user->city = (!empty($tool->city)) ? $tool->city : "";
+        $user->country = (!empty($tool->country)) ? $tool->country : "";
+        $user->institution = (!empty($tool->institution)) ? $tool->institution : "";
+        $user->timezone = (!empty($tool->timezone)) ? $tool->timezone : "";
+        $user->maildisplay = (!empty($tool->maildisplay)) ? $tool->maildisplay : $CFG->defaultpreference_maildisplay;
+        $user->mnethostid = $CFG->mnet_localhost_id;
+        $user->confirmed = 1;
+        $user->lang = $tool->lang;
+
+        return $user;
+    }
+
+    /**
+     * Compares two users.
+     *
+     * @param \stdClass $newuser The new user
+     * @param \stdClass $olduser The old user
+     * @return bool True if both users are the same
+     */
+    public static function user_match($newuser, $olduser) {
+        if ($newuser->firstname != $olduser->firstname) {
+            return false;
+        }
+        if ($newuser->lastname != $olduser->lastname) {
+            return false;
+        }
+        if ($newuser->email != $olduser->email) {
+            return false;
+        }
+        if ($newuser->city != $olduser->city) {
+            return false;
+        }
+        if ($newuser->country != $olduser->country) {
+            return false;
+        }
+        if ($newuser->institution != $olduser->institution) {
+            return false;
+        }
+        if ($newuser->timezone != $olduser->timezone) {
+            return false;
+        }
+        if ($newuser->maildisplay != $olduser->maildisplay) {
+            return false;
+        }
+        if ($newuser->mnethostid != $olduser->mnethostid) {
+            return false;
+        }
+        if ($newuser->confirmed != $olduser->confirmed) {
+            return false;
+        }
+        if ($newuser->lang != $olduser->lang) {
+            return false;
+        }
+
+        return true;
+    }
+
+    /**
+     * Updates the users profile image.
+     *
+     * @param int $userid the id of the user
+     * @param string $url the url of the image
+     * @return bool|string true if successful, else a string explaining why it failed
+     */
+    public static function update_user_profile_image($userid, $url) {
+        global $CFG, $DB;
+
+        require_once($CFG->libdir . '/filelib.php');
+        require_once($CFG->libdir . '/gdlib.php');
+
+        $fs = get_file_storage();
+
+        $context = \context_user::instance($userid, MUST_EXIST);
+        $fs->delete_area_files($context->id, 'user', 'newicon');
+
+        $filerecord = array(
+            'contextid' => $context->id,
+            'component' => 'user',
+            'filearea' => 'newicon',
+            'itemid' => 0,
+            'filepath' => '/'
+        );
+
+        $urlparams = array(
+            'calctimeout' => false,
+            'timeout' => 5,
+            'skipcertverify' => true,
+            'connecttimeout' => 5
+        );
+
+        if (!$iconfiles = $fs->create_file_from_url($filerecord, $url, $urlparams)) {
+            return self::PROFILE_IMAGE_UPDATE_FAILED;
+        }
+
+        $iconfile = $fs->get_area_files($context->id, 'user', 'newicon', false, 'itemid', false);
+
+        // There should only be one.
+        $iconfile = reset($iconfile);
+
+        // Something went wrong while creating temp file - remove the uploaded file.
+        if (!$iconfile = $iconfile->copy_content_to_temp()) {
+            $fs->delete_area_files($context->id, 'user', 'newicon');
+            return self::PROFILE_IMAGE_UPDATE_FAILED;
+        }
+
+        // Copy file to temporary location and the send it for processing icon.
+        $newpicture = (int) process_new_icon($context, 'user', 'icon', 0, $iconfile);
+        // Delete temporary file.
+        @unlink($iconfile);
+        // Remove uploaded file.
+        $fs->delete_area_files($context->id, 'user', 'newicon');
+        // Set the user's picture.
+        $DB->set_field('user', 'picture', $newpicture, array('id' => $userid));
+        return self::PROFILE_IMAGE_UPDATE_SUCCESSFUL;
+    }
+
+    /**
+     * Enrol a user in a course.
+     *
+     * @param \stdclass $tool The tool object (retrieved using self::get_lti_tool() or self::get_lti_tools())
+     * @param int $userid The user id
+     * @return bool|string returns true if successful, else an error code
+     */
+    public static function enrol_user($tool, $userid) {
+        global $DB;
+
+        // Check if the user enrolment exists.
+        if (!$DB->record_exists('user_enrolments', array('enrolid' => $tool->enrolid, 'userid' => $userid))) {
+            // Check if the maximum enrolled limit has been met.
+            if ($tool->maxenrolled) {
+                if ($DB->count_records('user_enrolments', array('enrolid' => $tool->enrolid)) >= $tool->maxenrolled) {
+                    return self::ENROLMENT_MAX_ENROLLED;
+                }
+            }
+            // Check if the enrolment has not started.
+            if ($tool->enrolstartdate && time() < $tool->enrolstartdate) {
+                return self::ENROLMENT_NOT_STARTED;
+            }
+            // Check if the enrolment has finished.
+            if ($tool->enrolenddate && time() > $tool->enrolenddate) {
+                return self::ENROLMENT_FINISHED;
+            }
+
+            $timeend = 0;
+            if ($tool->enrolperiod) {
+                $timeend = time() + $tool->enrolperiod;
+            }
+
+            // Finally, enrol the user.
+            $instance = new \stdClass();
+            $instance->id = $tool->enrolid;
+            $instance->courseid = $tool->courseid;
+            $instance->enrol = 'lti';
+            $instance->status = $tool->status;
+            $ltienrol = enrol_get_plugin('lti');
+            $ltienrol->enrol_user($instance, $userid, null, time(), $timeend);
+        }
+
+        return self::ENROLMENT_SUCCESSFUL;
+    }
+
+    /**
+     * Returns the LTI tool.
+     *
+     * @param int $toolid
+     * @return \stdClass the tool
+     */
+    public static function get_lti_tool($toolid) {
+        global $DB;
+
+        $sql = "SELECT elt.*, e.name, e.courseid, e.status, e.enrolstartdate, e.enrolenddate, e.enrolperiod
+                  FROM {enrol_lti_tools} elt
+                  JOIN {enrol} e
+                    ON elt.enrolid = e.id
+                 WHERE elt.id = :tid";
+
+        return $DB->get_record_sql($sql, array('tid' => $toolid), MUST_EXIST);
+    }
+
+    /**
+     * Returns the LTI tools requested.
+     *
+     * @param array $params The list of SQL params (eg. array('columnname' => value, 'columnname2' => value)).
+     * @param int $limitfrom return a subset of records, starting at this point (optional).
+     * @param int $limitnum return a subset comprising this many records in total
+     * @return array of tools
+     */
+    public static function get_lti_tools($params = array(), $limitfrom = 0, $limitnum = 0) {
+        global $DB;
+
+        $sql = "SELECT elt.*, e.name, e.courseid, e.status, e.enrolstartdate, e.enrolenddate, e.enrolperiod
+                  FROM {enrol_lti_tools} elt
+                  JOIN {enrol} e
+                    ON elt.enrolid = e.id";
+        if ($params) {
+            $where = "WHERE";
+            foreach ($params as $colname => $value) {
+                $sql .= " $where $colname = :$colname";
+                $where = "AND";
+            }
+        }
+        $sql .= " ORDER BY timecreated";
+
+        return $DB->get_records_sql($sql, $params, $limitfrom, $limitnum);
+    }
+
+    /**
+     * Returns the number of LTI tools.
+     *
+     * @param array $params The list of SQL params (eg. array('columnname' => value, 'columnname2' => value)).
+     * @return int The number of tools
+     */
+    public static function count_lti_tools($params = array()) {
+        global $DB;
+
+        $sql = "SELECT COUNT(*)
+                  FROM {enrol_lti_tools} elt
+                  JOIN {enrol} e
+                    ON elt.enrolid = e.id";
+        if ($params) {
+            $where = "WHERE";
+            foreach ($params as $colname => $value) {
+                $sql .= " $where $colname = :$colname";
+                $where = "AND";
+            }
+        }
+
+        return $DB->count_records_sql($sql, $params);
+    }
+
+    /**
+     * Create a IMS POX body request for sync grades.
+     *
+     * @param string $source Sourceid required for the request
+     * @param float $grade User final grade
+     * @return string
+     */
+    public static function create_service_body($source, $grade) {
+        return '<?xml version="1.0" encoding="UTF-8"?>
+            <imsx_POXEnvelopeRequest xmlns="http://www.imsglobal.org/services/ltiv1p1/xsd/imsoms_v1p0">
+              <imsx_POXHeader>
+                <imsx_POXRequestHeaderInfo>
+                  <imsx_version>V1.0</imsx_version>
+                  <imsx_messageIdentifier>' . (time()) . '</imsx_messageIdentifier>
+                </imsx_POXRequestHeaderInfo>
+              </imsx_POXHeader>
+              <imsx_POXBody>
+                <replaceResultRequest>
+                  <resultRecord>
+                    <sourcedGUID>
+                      <sourcedId>' . $source . '</sourcedId>
+                    </sourcedGUID>
+                    <result>
+                      <resultScore>
+                        <language>en-us</language>
+                        <textString>' . $grade . '</textString>
+                      </resultScore>
+                    </result>
+                  </resultRecord>
+                </replaceResultRequest>
+              </imsx_POXBody>
+            </imsx_POXEnvelopeRequest>';
+    }
+}