#98 Moved helper functions used by multiple elements

Also did the following -

1. Changed get_grade_items() so it takes a course parameter.
2. Renamed get_grade() and get_mod_grade() and changed functionality
   slightly to use newly introduced class.
3. Do not return a date graded value if there is no grade.
4. Added course grade date as an option to the date element.
5. Fix inconsistency between number of decimals showing for a grade
   between the drag and drop interface and the PDF.

classes/element_helper.php

@@ -26,6 +26,10 @@ namespace mod_customcert;
 
 defined('MOODLE_INTERNAL') || die();
 
+require_once($CFG->libdir . '/grade/constants.php');
+require_once($CFG->dirroot . '/grade/lib.php');
+require_once($CFG->dirroot . '/grade/querylib.php');
+
 /**
  * Class helper.
  *
@@ -417,4 +421,145 @@ class element_helper {
         \core_collator::asort($options);
         return $options;
     }
+
+    /**
+     * Helper function to return all the grades items for a given course.
+     *
+     * @param \stdClass $course The course we want to return the grade items for
+     * @return array the array of gradeable items in the course
+     */
+    public static function get_grade_items($course) {
+        global $DB;
+
+        // Array to store the grade items.
+        $modules = array();
+
+        // Collect course modules data.
+        $modinfo = get_fast_modinfo($course);
+        $mods = $modinfo->get_cms();
+        $sections = $modinfo->get_section_info_all();
+
+        // Create the section label depending on course format.
+        $sectionlabel = get_string('section');
+        if ($course->format == 'topics') {
+            $sectionlabel = get_string('topic');
+        } else if ($course->format == 'weeks') {
+            $sectionlabel = get_string('week');
+        }
+
+        // Loop through each course section.
+        for ($i = 0; $i <= count($sections) - 1; $i++) {
+            // Confirm the index exists, should always be true.
+            if (isset($sections[$i])) {
+                // Get the individual section.
+                $section = $sections[$i];
+                // Get the mods for this section.
+                $sectionmods = explode(",", $section->sequence);
+                // Loop through the section mods.
+                foreach ($sectionmods as $sectionmod) {
+                    // Should never happen unless DB is borked.
+                    if (empty($mods[$sectionmod])) {
+                        continue;
+                    }
+                    $mod = $mods[$sectionmod];
+                    $instance = $DB->get_record($mod->modname, array('id' => $mod->instance));
+                    // Get the grade items for this activity.
+                    if ($gradeitems = grade_get_grade_items_for_activity($mod)) {
+                        $moditem = grade_get_grades($course->id, 'mod', $mod->modname, $mod->instance);
+                        $gradeitem = reset($moditem->items);
+                        if (isset($gradeitem->grademax)) {
+                            $modules[$mod->id] = $sectionlabel . ' ' . $section->section . ' : ' . $instance->name;
+                        }
+                    }
+                }
+            }
+        }
+
+        return $modules;
+    }
+
+    /**
+     * Helper function to return the grade information for a course for a specified user.
+     *
+     * @param int $courseid
+     * @param int $gradeformat
+     * @param int $userid
+     * @return grade_information|bool the grade information, or false if there is none.
+     */
+    public static function get_course_grade_info($courseid, $gradeformat, $userid) {
+        $courseitem = \grade_item::fetch_course_item($courseid);
+
+        if (!$courseitem) {
+            return false;
+        }
+
+        // Define how many decimals to display.
+        $decimals = 2;
+        if ($gradeformat == GRADE_DISPLAY_TYPE_PERCENTAGE) {
+            $decimals = 0;
+        }
+
+        $grade = new \grade_grade(array('itemid' => $courseitem->id, 'userid' => $userid));
+
+        return new grade_information(
+            $courseitem->get_name(),
+            $grade->finalgrade,
+            grade_format_gradevalue($grade->finalgrade, $courseitem, true, $gradeformat, $decimals),
+            $grade->get_dategraded()
+        );
+    }
+
+    /**
+     * Helper function to return the grade information for a module for a specified user.
+     *
+     * @param int $cmid
+     * @param int $gradeformat
+     * @param int $userid
+     * @return grade_information|bool the grade information, or false if there is none.
+     */
+    public static function get_mod_grade_info($cmid, $gradeformat, $userid) {
+        global $DB;
+
+        if (!$cm = $DB->get_record('course_modules', array('id' => $cmid))) {
+            return false;
+        }
+
+        if (!$module = $DB->get_record('modules', array('id' => $cm->module))) {
+            return false;
+        }
+
+        $gradeitem = grade_get_grades($cm->course, 'mod', $module->name, $cm->instance, $userid);
+
+        if (empty($gradeitem)) {
+            return false;
+        }
+
+        // Define how many decimals to display.
+        $decimals = 2;
+        if ($gradeformat == GRADE_DISPLAY_TYPE_PERCENTAGE) {
+            $decimals = 0;
+        }
+
+        $item = new \grade_item();
+        $item->gradetype = GRADE_TYPE_VALUE;
+        $item->courseid = $cm->course;
+        $itemproperties = reset($gradeitem->items);
+        foreach ($itemproperties as $key => $value) {
+            $item->$key = $value;
+        }
+
+        $objgrade = $item->grades[$userid];
+
+        $dategraded = null;
+        if (!empty($objgrade->dategraded)) {
+            $dategraded = $objgrade->dategraded;
+        }
+
+        return new grade_information(
+            $item->name,
+            $objgrade->grade,
+            grade_format_gradevalue($objgrade->grade, $item, true, $gradeformat, $decimals),
+            $dategraded
+        );
+    }
 }

classes/grade_information.php

@@ -0,0 +1,108 @@
+<?php
+// This file is part of the customcert module for 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/>.
+
+/**
+ * Contains the class that provides a grade object to be used by elements for display purposes.
+ *
+ * @package    mod_customcert
+ * @copyright  2017 Mark Nelson <markn@moodle.com>
+ * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
+ */
+
+namespace mod_customcert;
+
+defined('MOODLE_INTERNAL') || die();
+
+/**
+ * The class that provides a grade object to be used by elements for display purposes.
+ *
+ * @package    mod_customcert
+ * @copyright  2017 Mark Nelson <markn@moodle.com>
+ * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
+ */
+class grade_information {
+
+    /**
+     * @var string The grade name.
+     */
+    protected $name;
+
+    /**
+     * @var float The raw grade.
+     */
+    protected $grade;
+
+    /**
+     * @var string The grade to display
+     */
+    protected $displaygrade;
+
+    /**
+     * @var int The date it was graded.
+     */
+    protected $dategraded;
+
+    /**
+     * The constructor.
+     *
+     * @param string $name
+     * @param float $grade
+     * @param string $displaygrade
+     * @param int $dategraded
+     */
+    public function __construct($name, $grade, $displaygrade, $dategraded) {
+        $this->name = $name;
+        $this->grade = $grade;
+        $this->displaygrade = $displaygrade;
+        $this->dategraded = $dategraded;
+    }
+
+    /**
+     * Returns the name.
+     *
+     * @return string
+     */
+    public function get_name() {
+        return $this->name;
+    }
+
+    /**
+     * Returns the raw grade.
+     *
+     * @return float
+     */
+    public function get_grade() {
+        return $this->grade;
+    }
+
+    /**
+     * Returns the display grade.
+     *
+     * @return string
+     */
+    public function get_displaygrade() {
+        return $this->displaygrade;
+    }
+
+    /**
+     * Returns the date it was graded.
+     *
+     * @return int
+     */
+    public function get_dategraded() {
+        return $this->dategraded;
+    }
+}