lib/form/grading.php

   1 <?php
   2 // This file is part of Moodle - http://moodle.org/
   3 //
   4 // Moodle is free software: you can redistribute it and/or modify
   5 // it under the terms of the GNU General Public License as published by
   6 // the Free Software Foundation, either version 3 of the License, or
   7 // (at your option) any later version.
   8 //
   9 // Moodle is distributed in the hope that it will be useful,
  10 // but WITHOUT ANY WARRANTY; without even the implied warranty of
  11 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12 // GNU General Public License for more details.
  13 //
  14 // You should have received a copy of the GNU General Public License
  15 // along with Moodle.  If not, see <http://www.gnu.org/licenses/>.
  16
  17
  18 /**
  19  * Advance grading form element
  20  *
  21  * Element-container for advanced grading custom input
  22  *
  23  * @package   core_form
  24  * @copyright 2011 Marina Glancy
  25  * @license   http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
  26  */
  27
  28 global $CFG;
  29 require_once("HTML/QuickForm/element.php");
  30 require_once($CFG->dirroot.'/grade/grading/form/lib.php');
  31 require_once('templatable_form_element.php');
  32
  33 if (class_exists('HTML_QuickForm')) {
  34     HTML_QuickForm::registerRule('gradingvalidated', 'callback', '_validate', 'MoodleQuickForm_grading');
  35 }
  36
  37 /**
  38  * Advance grading form element
  39  *
  40  * HTML class for a grading element. This is a wrapper for advanced grading plugins.
  41  * When adding the 'grading' element to the form, developer must pass an object of
  42  * class gradingform_instance as $attributes['gradinginstance']. Otherwise an exception will be
  43  * thrown.
  44  * This object is responsible for implementing functions to render element html and validate it
  45  *
  46  * @package   core_form
  47  * @category  form
  48  * @copyright 2011 Marina Glancy
  49  * @license   http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
  50  */
  51 class MoodleQuickForm_grading extends HTML_QuickForm_input implements templatable {
  52     use templatable_form_element {
  53         export_for_template as export_for_template_base;
  54     }
  55
  56     /** @var string html for help button, if empty then no help */
  57     var $_helpbutton='';
  58
  59     /** @var array Stores attributes passed to the element */
  60     private $gradingattributes;
  61
  62     /**
  63      * Class constructor
  64      *
  65      * @param string $elementName Input field name attribute
  66      * @param mixed $elementLabel Label(s) for the input field
  67      * @param mixed $attributes Either a typical HTML attribute string or an associative array
  68      */
  69     public function __construct($elementName=null, $elementLabel=null, $attributes=null) {
  70         parent::__construct($elementName, $elementLabel, $attributes);
  71         $this->_type = 'grading';
  72         $this->gradingattributes = $attributes;
  73     }
  74
  75     /**
  76      * Old syntax of class constructor. Deprecated in PHP7.
  77      *
  78      * @deprecated since Moodle 3.1
  79      */
  80     public function MoodleQuickForm_grading($elementName=null, $elementLabel=null, $attributes=null) {
  81         debugging('Use of class name as constructor is deprecated', DEBUG_DEVELOPER);
  82         self::__construct($elementName, $elementLabel, $attributes);
  83     }
  84
  85     /**
  86      * Helper function to retrieve gradingform_instance passed in element attributes
  87      *
  88      * @return gradingform_instance
  89      */
  90     public function get_gradinginstance() {
  91         if (is_array($this->gradingattributes) && array_key_exists('gradinginstance', $this->gradingattributes)) {
  92             return $this->gradingattributes['gradinginstance'];
  93         } else {
  94             return null;
  95         }
  96     }
  97
  98     /**
  99      * Returns the input field in HTML
 100      *
 101      * @return string
 102      */
 103     public function toHtml(){
 104         global $PAGE;
 105         return $this->get_gradinginstance()->render_grading_element($PAGE, $this);
 106     }
 107
 108     /**
 109      * get html for help button
 110      *
 111      * @return string html for help button
 112      */
 113     public function getHelpButton(){
 114         return $this->_helpbutton;
 115     }
 116
 117     /**
 118      * The renderer of gradingform_instance will take care itself about different display
 119      * in normal and frozen states
 120      *
 121      * @return string
 122      */
 123     public function getElementTemplateType(){
 124         return 'default';
 125     }
 126
 127     /**
 128      * Called by HTML_QuickForm whenever form event is made on this element.
 129      * Adds necessary rules to the element and checks that coorenct instance of gradingform_instance
 130      * is passed in attributes
 131      *
 132      * @param string $event Name of event
 133      * @param mixed $arg event arguments
 134      * @param object $caller calling object
 135      * @return bool
 136      * @throws moodle_exception
 137      */
 138     public function onQuickFormEvent($event, $arg, &$caller) {
 139         if ($event == 'createElement') {
 140             $attributes = $arg[2];
 141             if (!is_array($attributes) || !array_key_exists('gradinginstance', $attributes) || !($attributes['gradinginstance'] instanceof gradingform_instance)) {
 142                 throw new moodle_exception('exc_gradingformelement', 'grading');
 143             }
 144         }
 145
 146         $name = $this->getName();
 147         if ($name && $caller->elementExists($name)) {
 148             $caller->addRule($name, $this->get_gradinginstance()->default_validation_error_message(), 'gradingvalidated', $this->gradingattributes);
 149         }
 150         return parent::onQuickFormEvent($event, $arg, $caller);
 151     }
 152
 153     /**
 154      * Function registered as rule for this element and is called when this element is being validated.
 155      * This is a wrapper to pass the validation to the method gradingform_instance::validate_grading_element
 156      *
 157      * @param mixed $elementvalue value of element to be validated
 158      * @param array $attributes element attributes
 159      * @return MoodleQuickForm_grading
 160      */
 161     public static function _validate($elementvalue, $attributes = null) {
 162         if (!$attributes['gradinginstance']->is_empty_form($elementvalue)) {
 163             return $attributes['gradinginstance']->validate_grading_element($elementvalue);
 164         }
 165         return true;
 166     }
 167
 168     public function export_for_template(renderer_base $output) {
 169         $context = $this->export_for_template_base($output);
 170         $context['html'] = $this->toHtml();
 171         return $context;
 172     }
 173 }