PostgreSQL doesn't like aliases in update statements.

[moodle.git] / grade / export / lib.php

<?php

///////////////////////////////////////////////////////////////////////////
//                                                                       //
// NOTICE OF COPYRIGHT                                                   //
//                                                                       //
// Moodle - Modular Object-Oriented Dynamic Learning Environment         //
//          http://moodle.com                                            //
//                                                                       //
// Copyright (C) 1999 onwards  Martin Dougiamas  http://moodle.com       //
//                                                                       //
// This program 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 2 of the License, or     //
// (at your option) any later version.                                   //
//                                                                       //
// This program 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:                          //
//                                                                       //
//          http://www.gnu.org/copyleft/gpl.html                         //
//                                                                       //
///////////////////////////////////////////////////////////////////////////

require_once($CFG->dirroot.'/lib/gradelib.php');
require_once($CFG->dirroot.'/grade/lib.php');
require_once($CFG->dirroot.'/grade/export/grade_export_form.php');

/**
 * Base export class
 */
class grade_export {

    var $plugin; // plgin name - must be filled in subclasses!

    var $grade_items; // list of all course grade items
    var $groupid;     // groupid, 0 means all groups
    var $course;      // course object
    var $columns;     // array of grade_items selected for export

    var $previewrows;     // number of rows in preview
    var $export_letters;  // export letters - TODO: finish implementation
    var $export_feedback; // export feedback
    var $userkey;         // export using private user key

    var $letters;     // internal
    var $report;      // internal

    /**
     * Constructor should set up all the private variables ready to be pulled
     * @param object $course
     * @param int $groupid id of selected group, 0 means all
     * @param string $itemlist comma separated list of item ids, empty means all
     * @param boolean $export_feedback
     * @param boolean $export_letters
     * @note Exporting as letters will lead to data loss if that exported set it re-imported.
     */
    function grade_export($course, $groupid=0, $itemlist='', $export_feedback=false, $export_letters=false) {
        $this->course = $course;
        $this->groupid = $groupid;
        $this->grade_items = grade_item::fetch_all(array('courseid'=>$this->course->id));

        $this->columns = array();
        if (!empty($itemlist)) {
            $itemids = explode(',', $itemlist);
            // remove items that are not requested
            foreach ($itemids as $itemid) {
                if (array_key_exists($itemid, $this->grade_items)) {
                    $this->columns[$itemid] =& $this->grade_items[$itemid];
                }
            }
        } else {
            foreach ($this->grade_items as $itemid=>$unused) {
                $this->columns[$itemid] =& $this->grade_items[$itemid];
            }
        }

        $this->export_letters  = $export_letters;
        $this->export_feedback = $export_feedback;
        $this->userkey         = '';
        $this->previewrows     = false;
    }

    /**
     * Init object based using data from form
     * @param object $formdata
     */
    function process_form($formdata) {
        global $USER;

        $this->columns = array();
        if (!empty($formdata->itemids)) {
            foreach ($formdata->itemids as $itemid=>$selected) {
                if ($selected and array_key_exists($itemid, $this->grade_items)) {
                    $this->columns[$itemid] =& $this->grade_items[$itemid];
                }
            }
        } else {
            foreach ($this->grade_items as $itemid=>$unused) {
                $this->columns[$itemid] =& $this->grade_items[$itemid];
            }
        }

        if (isset($formdata->key)) {
            if ($formdata->key == 1 && isset($formdata->iprestriction) && isset($formdata->validuntil)) {
                // Create a new key
                $formdata->key = create_user_key('grade/export', $USER->id, $this->course->id, $formdata->iprestriction, $formdata->validuntil);
            }
            $this->userkey = $formdata->key;
        }

        if (isset($formdata->export_letters)) {
            $this->export_letters = $formdata->export_letters;
        }

        if (isset($formdata->export_feedback)) {
            $this->export_feedback = $formdata->export_feedback;
        }

        if (isset($formdata->previewrows)) {
            $this->previewrows = $formdata->previewrows;
        }

    }

    /**
     * Update exported field in grade_grades table
     * @return boolean
     */
    function track_exports() {
        global $CFG;

        /// Whether this plugin is entitled to update export time
        if ($expplugins = explode(",", $CFG->gradeexport)) {
            if (in_array($this->plugin, $expplugins)) {
                return true;
            } else {
                return false;
          }
        } else {
            return false;
        }
    }

    /**
     * internal
     */
    function _init_letters() {
        global $CFG;

        if (!isset($this->letters)) {
            if ($this->export_letters) {
                require_once($CFG->dirroot . '/grade/report/lib.php');
                $this->report = new grade_report($this->course->id, null, null);
                $this->letters = $this->report->get_grade_letters();
            } else {
                $this->letters = false; // false prevents another fetching of grade letters
            }
        }
    }

    /**
     * Returns string representation of final grade
     * @param $object $grade instance of grade_grade class
     * @return string
     */
    function format_grade($grade) {
        $this->_init_letters();

        //TODO: rewrite the letters handling code - this is slow
        if ($this->letters) {
            $grade_item = $this->grade_items[$grade->itemid];
            $grade_item_displaytype = $this->report->get_pref('gradedisplaytype', $grade_item->id);

            if ($grade_item_displaytype == GRADE_REPORT_GRADE_DISPLAY_TYPE_LETTER) {
                return grade_grade::get_letter($this->letters, $grade->finalgrade, $grade_item->grademin, $grade_item->grademax);
            }
        }

        //TODO: format it somehow - scale/letter/number/etc.
        return $grade->finalgrade;
    }

    /**
     * Returns the name of column in export
     * @param object $grade_item
     * @param boolena $feedback feedback colum
     * &return string
     */
    function format_column_name($grade_item, $feedback=false) {
        if ($grade_item->itemtype == 'mod') {
            $name = get_string('modulename', $grade_item->itemmodule).': '.$grade_item->get_name();
        } else {
            $name = $grade_item->get_name();
        }

        if ($feedback) {
            $name .= ' ('.get_string('feedback').')';
        }

        return strip_tags($name);
    }

    /**
     * Returns formatted grade feedback
     * @param object $feedback object with properties feedback and feedbackformat
     * @return string
     */
    function format_feedback($feedback) {
        return strip_tags(format_text($feedback->feedback, $feedback->feedbackformat));
    }

    /**
     * Implemented by child class
     */
    function print_grades() { }

    /**
     * Prints preview of exported grades on screen as a feedback mechanism
     */
    function display_preview() {
        echo '<table>';
        echo '<tr>';
        echo '<th>'.get_string("firstname")."</th>".
             '<th>'.get_string("lastname")."</th>".
             '<th>'.get_string("idnumber")."</th>".
             '<th>'.get_string("institution")."</th>".
             '<th>'.get_string("department")."</th>".
             '<th>'.get_string("email")."</th>";
        foreach ($this->columns as $grade_item) {
            echo '<th>'.$this->format_column_name($grade_item).'</th>';

            /// add a column_feedback column
            if ($this->export_feedback) {
                echo '<th>'.$this->format_column_name($grade_item, true).'</th>';
            }
        }
        echo '</tr>';
        /// Print all the lines of data.

        $i = 0;
        $gui = new graded_users_iterator($this->course, $this->columns, $this->groupid);
        $gui->init();
        while ($userdata = $gui->next_user()) {
            // number of preview rows
            if ($this->previewrows and $this->previewrows < ++$i) {
                break;
            }
            $user = $userdata->user;

            echo '<tr>';
            echo "<td>$user->firstname</td><td>$user->lastname</td><td>$user->idnumber</td><td>$user->institution</td><td>$user->department</td><td>$user->email</td>";
            foreach ($this->columns as $itemid=>$unused) {
                $gradetxt = $this->format_grade($userdata->grades[$itemid]);
                echo "<td>$gradetxt</td>";

                if ($this->export_feedback) {
                    echo '<td>'.$this->format_feedback($userdata->feedbacks[$itemid]).'</td>';
                }
            }
            echo "</tr>";
        }
        echo '</table>';
        $gui->close();
    }

    /**
     * Returns array of parameters used by dump.php and export.php.
     * @return array
     */
    function get_export_params() {
        $itemids = array_keys($this->columns);

        $params = array('id'             =>$this->course->id,
                        'groupid'        =>$this->groupid,
                        'itemids'        =>implode(',', $itemids),
                        'export_letters' =>$this->export_letters,
                        'export_feedback'=>$this->export_feedback);

        return $params;
    }

    /**
     * Either prints a "Export" box, which will redirect the user to the download page,
     * or prints the URL for the published data.
     * @note exit() at the end of the method
     * @return void
     */
    function print_continue() {
        global $CFG;

        $params = $this->get_export_params();

        // this button should trigger a download prompt
        if (!$this->userkey) {
            print_single_button($CFG->wwwroot.'/grade/export/'.$this->plugin.'/export.php', $params, get_string('export', 'grades'));

        } else {
            $paramstr = '';
            $sep = '?';
            foreach($params as $name=>$value) {
                $paramstr .= $sep.$name.'='.$value;
                $sep = '&amp;';
            }

            $link = $CFG->wwwroot.'/grade/export/'.$this->plugin.'/dump.php'.$paramstr.'&amp;key='.$this->userkey;

            echo '<p>';
            echo '<a href="'.$link.'">'.$link.'</a>';
            echo '</p>';
            print_footer();
        }
        exit();
    }
}

?>