locallib.php

<?php
// This file is not a part of Moodle - http://moodle.org/
// This is a none core contributed module.
//
// This 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.
//
// This 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.
//
// The GNU General Public License
// can be see at <http://www.gnu.org/licenses/>.

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

class invitation_manager {
    
    /*
     * The invitation enrol instance of a course
     */
    var $enrol_instance = null;
    
    /*
     * The course id
     */
    var $courseid = null;
    
    /**
     *
     * @param type $courseid 
     */
    public function __construct($courseid, $instancemustexist = true) {
        $this->courseid = $courseid;
        $this->enrol_instance = $this->get_invitation_instance($courseid, $instancemustexist);
    }

    /**
     * DEPRECATED
     * Return HTML invitation menu link for a given course
     * It's mostly useful to add a link in a block menu - by default icon is displayed.
     * @param boolean $withicon - set to false to not display the icon
     * @return
     * @deprecated 24/02/13 - nothing is using this function and at best it should be in lib.php. This function will not be removed before 2014.
     */
    public function get_menu_link($withicon = true) {
        global $OUTPUT;
        
        $inviteicon = '';
        $link = '';
       
        if (has_capability('enrol/invitation:enrol',
                        get_context_instance(CONTEXT_COURSE, $this->courseid))
                and ($this->leftinvitationfortoday() > 0)) {
            
            //display an icon with requested (css can be changed in stylesheet)
            if ($withicon) {
                $inviteicon = html_writer::empty_tag('img',
                            array('alt' => "invitation", 'class' => "enrol_invitation_item_icon", 'title' => "invitation",
                                'src' => $OUTPUT->pix_url('invite', 'enrol_invitation')));
            }
            
            $link = html_writer::link(
                new moodle_url('/enrol/invitation/invitation.php',
                        array('courseid' => $this->courseid)),
                $inviteicon . get_string('inviteusers', 'enrol_invitation'));
            
        }
        
        return $link;
    }
    
    /**
     * Return the number of invitation that can still be sent today for a specific course
     * If users accept quickly their invitation then you can send a lot more email per day
     * It is just to avoid spam.
     * @return int number of left invitation to send 
     */
    public function leftinvitationfortoday($courseid = null) {
        global $DB;
        
        if (empty($courseid)) {
            $courseid = $this->courseid;
        }
        
        $onedayearlier = time() - (60 * 60 * 24);
        $sentinvitations = $DB->get_records_select('enrol_invitation', 
                'timesent > ? AND tokenused = 0', array($onedayearlier));
        $invitationleft = $this->enrol_instance->customint1 - count($sentinvitations);
        $invitationleft = ($invitationleft>0)?$invitationleft:0;
        return $invitationleft;
    }
    
    /**
     * Send invitation (create a unique token for each of them)
     * @global type $USER
     * @global type $DB
     * @param type $data 
     */
    public function send_invitations($data) {
        global $USER, $DB, $SITE;
        
         $data = (array) $data;
        
        //check that the user didn't send more than MAX INVITATION invitation per day
        $invitationleft = $this->leftinvitationfortoday($data['courseid']);
        
        //to send invitation you must able to edit the course - no need to be able to enrol into the course
        if (has_capability('enrol/invitation:enrol',
                        context_course::instance($data['courseid']))) {
            for ($indice = 1; $indice <= $invitationleft; $indice = $indice + 1) {
                
                $invitationleft = $invitationleft - 1;
                if ($invitationleft < 0) {
                    throw new moodle_exception('cannotsendmoreinvitationfortoday', 'enrol_invitation');
                }
                
                $email = $data['email' . $indice];
                if (!empty($email)) {

                    //create unique token for invitation
                    $token = md5(uniqid(rand(),1));
                    $existingtoken = $DB->get_record('enrol_invitation', array('token' => $token));
                    while (!empty($existingtoken)) {
                        $token = md5(uniqid(rand(),1));
                        $existingtoken = $DB->get_record('enrol_invitation', array('token' => $token));
                    }

                    //save token information in config (token value, course id, TODO: role id)
                    $invitation = new stdClass();
                    $invitation->courseid = $data['courseid'];
                    $invitation->email = $email;
                    $invitation->creatorid = $USER->id;
                    $invitation->token = $token;
                    $invitation->tokenused = false;
                    $invitation->timesent = time();
                    
                    $DB->insert_record('enrol_invitation', $invitation);
                    
                    $enrolurl = new moodle_url('/enrol/invitation/enrol.php',
                            array('enrolinvitationtoken' => $token, 'id' => $data['courseid']));

                    //send invitation to the user
                    $contactuser = new stdClass;
                    $contactuser->email = $email;
                    $contactuser->firstname = '';
                    $contactuser->lastname = '';
                    $contactuser->maildisplay = true;
                    $emailinfo = new stdClass();
                    $emailinfo->fullname = $data['fullname'];
                    $emailinfo->managername = $USER->firstname.' '.$USER->lastname;
                    $emailinfo->enrolurl = $enrolurl->out(false);
                    $emailinfo->sitename = $SITE->fullname;
                    $siteurl = new moodle_url('/');
                    $emailinfo->siteurl = $siteurl->out(false);
                    email_to_user($contactuser, $USER,
                            get_string('emailtitleinvitation', 'enrol_invitation', $emailinfo),
                            get_string('emailmessageinvitation', 'enrol_invitation', $emailinfo));
                }
            }
        } else {
            throw new moodle_exception('cannotsendinvitation', 'enrol_invitation',
                    new moodle_url('/course/view.php', array('id' => $data['courseid'])));
        }
        
    }
    
    /**
     * Return the invitation instance for a specific course
     * Note: as using $PAGE variable, this functio can only be called in a Moodle script page
     * @global object $PAGE
     * @param int $courseid
     * @param boolean $mustexist when set, an exception is thrown if no instance is found
     * @return type 
     */
    public function get_invitation_instance($courseid, $mustexist = false) {
        global $PAGE, $CFG, $DB;
        
        if (($courseid == $this->courseid) and !empty($this->enrol_instance)) {
            return $this->enrol_instance;
        }
        
         //find enrolment instance
        $instance = null;
        require_once("$CFG->dirroot/enrol/locallib.php");
        $course = $DB->get_record('course', array('id' => $courseid), '*', MUST_EXIST);
        $manager = new course_enrolment_manager($PAGE, $course);
        foreach ($manager->get_enrolment_instances() as $tempinstance) {
            if ($tempinstance->enrol == 'invitation') {
                if ($instance === null) {
                    $instance = $tempinstance;
                }
            }
        }
        
        if ($mustexist and empty($instance)) {
            throw new moodle_exception('noinvitationinstanceset', 'enrol_invitation');
        }
        
        return $instance;
        
    }

    /**
     * Enrol the user following the invitation data
     * @param object $invitation 
     */
    public function enroluser() {
        global $USER, $DB, $PAGE, $CFG;

        $enrol = enrol_get_plugin('invitation');
        $enrol->enrol_user($this->enrol_instance, $USER->id, $this->enrol_instance->roleid);
    }
}