TextCheckboxGroupField.php

<?php

namespace DNADesign\Elemental\Forms;

use SilverStripe\Forms\CheckboxField;
use SilverStripe\Forms\CompositeField;
use SilverStripe\Forms\LiteralField;
use SilverStripe\Forms\TextField;

class TextCheckboxGroupField extends CompositeField
{
    protected $schemaComponent = 'TextCheckboxGroupField';

    /**
     * Set the composite's title to that of the first child
     *
     * @param string|null $title
     */
    public function __construct($title = null)
    {
        if (!$title) {
            $title = _t(__CLASS__ . '.Title', 'Title');
        }

        $fields = [
            TextField::create('Title', $title),
            CheckboxField::create('ShowTitle', _t(__CLASS__ . '.ShowTitleLabel', 'Displayed'))
        ];

        parent::__construct($fields);

        $this->setTitle($title);
    }

    /**
     * Don't use the custom template for readonly states
     *
     * {@inheritDoc}
     */
    public function performReadonlyTransformation()
    {
        $field = $this;

        if (!$this->readonly) {
            $field = parent::performReadonlyTransformation();

            $field->setTemplate(CompositeField::class);
            $field->setTitle('Title');

            $titleField = $field->fieldByName('Title');
            if ($titleField) {
                $field->replaceField('Title', LiteralField::create(
                    'Title',
                    $titleField->Value()
                ));
            }

            $displayedText = _t(__CLASS__ . '.DISPLAYED', 'Displayed');
            $notDisplayedText = _t(__CLASS__ . '.NOT_DISPLAYED', 'Not displayed');
            $showTitle = $field->fieldByName('ShowTitle');
            if ($showTitle) {
                $field->replaceField('ShowTitle', LiteralField::create(
                    'ShowTitle',
                    $showTitle->Value() === 'Yes' ? $displayedText : $notDisplayedText
                )->addExtraClass('show-title'));
            }
        }

        return $field;
    }
}