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
28global $CFG;
29require_once("HTML/QuickForm/element.php");
30require_once($CFG->dirroot.'/grade/grading/form/lib.php');
31require_once('templatable_form_element.php');
32
33if (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 */
51class 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}
174