<?php
           
       namespace Modules\WidgetNameHere;
           
       use Zabbix\Core\CWidget;
           
       class Widget extends CWidget {
           
           public const MY_CONSTANT = 0;
           
           public function getTranslationStrings(): array {
               return [
                   'class.widget.js' => [
                       'No data' => _('No data')
                   ]
               ];
           }
       }

<?php
           
       namespace Modules\WidgetNameHere\Includes;
           
       use Modules\WidgetNameHere\Widget;
       use Zabbix\Widgets\CWidgetField;
       use Zabbix\Widgets\CWidgetForm;
           
       use Zabbix\Widgets\Fields\CWidgetFieldMultiSelectItem;
       use Zabbix\Widgets\Fields\CWidgetFieldTextBox;
       
       
       class WidgetForm extends CWidgetForm {
           
           public function addFields(): self {
               return $this
                   ->addField(
                       (new CWidgetFieldMultiSelectItem('itemid', _('Item')))
                           ->setFlags(CWidgetField::FLAG_NOT_EMPTY | CWidgetField::FLAG_LABEL_ASTERISK)
                           ->setMultiple(false)
                           ->setFilterParameter('numeric', true)
                   )
                   ->addField(
                       new CWidgetFieldTextBox('description', _('Description'))
                   );
           }
       }

<?php
           
       /**
        * My custom widget form view.
        *
        * @var CView $this
        * @var array $data
        */
       
       use Zabbix\Widgets\Fields\CWidgetFieldMultiSelectItem;
       use Zabbix\Widgets\Fields\CWidgetFieldTextBox;
       
       (new CWidgetFormView($data))
           ->addField(
               new CWidgetFieldMultiSelectItemView($data['fields']['itemid'], $data['captions']['ms']['items']['itemid'])
           )
           ->addField(
               new CWidgetFieldTextBoxView($data['fields']['description']),
               'js-advanced-configuration'
           )
           ->includeJsFile('widget.edit.js.php')
           ->addJavaScript('my_widget_form.init('.json_encode([
                   'color_palette' => CWidgetFieldGraphDataSet::DEFAULT_COLOR_PALETTE
               ], JSON_THROW_ON_ERROR).');')
           ->show();   

<?php
       
       use Modules\LessonGaugeChart\Widget;
       
       ?>
       
       window.widget_lesson_gauge_chart_form = new class {
       
           init({color_palette}) {
               this._advanced_configuration = document.getElementById('adv_conf');
       
               this._advanced_configuration.addEventListener('change', () => this.updateForm());
       
               colorPalette.setThemeColors(color_palette);
       
               for (const colorpicker of jQuery('.<?= ZBX_STYLE_COLOR_PICKER ?> input')) {
                   jQuery(colorpicker).colorpicker();
               }
       
               const overlay = overlays_stack.getById('widget_properties');
       
               for (const event of ['overlay.reload', 'overlay.close']) {
                   overlay.$dialogue[0].addEventListener(event, () => { jQuery.colorpicker('hide'); });
               }
       
               this.updateForm();
           }
       
           updateForm() {
               const show_advanced_configuration = this._advanced_configuration.checked;
       
               for (const element of this._form.querySelectorAll('.js-advanced-configuration')) {
                   element.style.display = show_advanced_configuration ? '' : 'none';
               }
           }
       };