lib/form/choicedropdown.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 defined('MOODLE_INTERNAL') || die();
  18
  19 use core\output\choicelist;
  20 use core\output\local\dropdown\status;
  21
  22 require_once('HTML/QuickForm/select.php');
  23 require_once('templatable_form_element.php');
  24
  25 /**
  26  * User choice using a dropdown type form element.
  27  *
  28  * @package   core_form
  29  * @category  form
  30  * @copyright 2023 Ferran Recio <ferran@moodle.com>
  31  * @license   http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
  32  */
  33 class MoodleQuickForm_choicedropdown extends HTML_QuickForm_select implements templatable {
  34
  35     use templatable_form_element {
  36         export_for_template as export_for_template_base;
  37     }
  38
  39     /**
  40      * @var string html for help button, if empty then no help.
  41      */
  42     protected string $_helpbutton = '';
  43
  44     /**
  45      * @var bool if true label will be hidden.
  46      */
  47     protected bool $_hiddenLabel = false;
  48
  49     /**
  50      * @var choicelist the user choices.
  51      */
  52     protected ?choicelist $choice = null;
  53
  54     /**
  55      * @var string[] Dropdown dialog width.
  56      */
  57     public const WIDTH = status::WIDTH;
  58
  59     /**
  60      * @var string the dropdown width (from core\output\local\dropdown\status::WIDTH).
  61      */
  62     protected string $dropdownwidth = status::WIDTH['small'];
  63
  64     /**
  65      * Constructor.
  66      *
  67      * @param string $elementname Select name attribute
  68      * @param mixed $elementlabel Label(s) for the select
  69      * @param choicelist $options Data to be used to populate options
  70      * @param mixed $attributes Either a typical HTML attribute string or an associative array
  71      */
  72     public function __construct(
  73         $elementname = null,
  74         $elementlabel = null,
  75         choicelist $options = null,
  76         $attributes = null
  77     ) {
  78         parent::__construct($elementname, $elementlabel, $options, $attributes);
  79         $this->_type = 'choicedropdown';
  80     }
  81
  82     /**
  83      * Set the dropdown width.
  84      *
  85      * @param string $width
  86      */
  87     public function set_dialog_width(string $width) {
  88         $this->dropdownwidth = $width;
  89     }
  90
  91     /**
  92      * Loads options from a choicelist.
  93      *
  94      * @param choicelist $choice Options source currently supports assoc array or DB_result
  95      * @param string|null $value optional value (in case it is not defined in the choicelist)
  96      * @param string|null $unused2 unused
  97      * @param string|null $unused3 unused
  98      * @param string|null $unused4 unused
  99      * @return bool
 100      */
 101     public function load(&$choice, $value = null, $unused2 = null, $unused3 = null, $unused4 = null): bool {
 102         if (!$choice instanceof choicelist) {
 103             throw new coding_exception('Choice must be instance of choicelist');
 104         }
 105         $this->choice = $choice;
 106         $this->choice->set_allow_empty(false);
 107         if ($value !== null && is_string($value)) {
 108             $choice->set_selected_value($value);
 109         }
 110         $this->setSelected($choice->get_selected_value());
 111         return true;
 112     }
 113
 114     /**
 115      * Sets label to be hidden
 116      *
 117      * @param bool $hiddenLabel sets if label should be hidden
 118      */
 119     public function setHiddenLabel($hiddenLabel) {
 120         $this->_hiddenLabel = $hiddenLabel;
 121     }
 122
 123     /**
 124      * Returns HTML for select form element.
 125      *
 126      * This method is only needed when forms renderer is forces via
 127      * $GLOBALS['_HTML_QuickForm_default_renderer']. Otherwise the
 128      * renderer will use mustache templates.
 129      *
 130      * @return string
 131      */
 132     public function toHtml(): string {
 133         $html = '';
 134         if ($this->_hiddenLabel) {
 135             $this->_generateId();
 136             $html .= '<label class="accesshide" for="'.$this->getAttribute('id').'" >'.$this->getLabel().'</label>';
 137         }
 138         $html .= parent::toHtml();
 139         return $html;
 140     }
 141
 142     /**
 143      * get html for help button
 144      *
 145      * @return string html for help button
 146      */
 147     public function getHelpButton(): string {
 148         return $this->_helpbutton;
 149     }
 150
 151     /**
 152      * Slightly different container template when frozen. Don't want to use a label tag
 153      * with a for attribute in that case for the element label but instead use a div.
 154      * Templates are defined in renderer constructor.
 155      *
 156      * @return string
 157      */
 158     public function getElementTemplateType(): string {
 159         if ($this->_flagFrozen) {
 160             return 'static';
 161         } else {
 162             return 'default';
 163         }
 164     }
 165
 166     /**
 167      * We check the options and return only the values that _could_ have been
 168      * selected. We also return a scalar value if select is not "multiple"
 169      *
 170      * @param string $submitvalues submitted values
 171      * @param bool $assoc if true the returned value is associated array
 172      * @return string|null
 173      */
 174     public function exportValue(&$submitvalues, $assoc = false) {
 175         $value = $this->_findValue($submitvalues) ?? $this->getValue();
 176         if (is_array($value)) {
 177             $value = reset($value);
 178         }
 179         if ($value === null) {
 180             return $this->_prepareValue($value, $assoc);
 181         }
 182         if (!$this->choice->has_value($value)) {
 183             $value = $this->choice->get_selected_value();
 184         }
 185         return $this->_prepareValue($value, $assoc);
 186     }
 187
 188     public function export_for_template(renderer_base $output): array {
 189         $context = $this->export_for_template_base($output);
 190
 191         if (!empty($this->_values)) {
 192             $this->choice->set_selected_value(reset($this->_values));
 193         }
 194
 195         $dialog = new status(
 196             $this->choice->get_selected_content($output),
 197             $this->choice,
 198             [
 199                 'extras' => ['data-form-controls' => $context['id']],
 200                 'buttonsync' => true,
 201                 'updatestatus' => true,
 202                 'dialogwidth' => $this->dropdownwidth,
 203             ]
 204         );
 205         $context['dropdown'] = $dialog->export_for_template($output);
 206         $context['select'] = $this->choice->export_for_template($output);
 207         $context['nameraw'] = $this->getName();
 208         return $context;
 209     }
 210 }