NEW Add composite field for Title and ShowTitle fields with readonly state as composite

src/Forms/TextCheckboxGroupField.php

@@ -0,0 +1,35 @@
+<?php
+
+namespace DNADesign\Elemental\Forms;
+
+use SilverStripe\Forms\CompositeField;
+
+class TextCheckboxGroupField extends CompositeField
+{
+    /**
+     * Set the composite's title to that of the first child
+     *
+     * {@inheritDoc}
+     */
+    public function __construct(...$children)
+    {
+        parent::__construct($children);
+
+        $this->setTitle($this->getChildren()->first()->Title());
+    }
+
+    /**
+     * Don't use the custom template for readonly states
+     *
+     * {@inheritDoc}
+     */
+    public function performReadonlyTransformation()
+    {
+        $field = parent::performReadonlyTransformation();
+
+        $field->setTemplate(CompositeField::class);
+        $field->setTitle(null);
+
+        return $field;
+    }
+}

src/Models/BaseElement.php

@@ -3,6 +3,7 @@
 namespace DNADesign\Elemental\Models;
 
 use Exception;
+use DNADesign\Elemental\Forms\TextCheckboxGroupField;
 use DNADesign\Elemental\Controllers\ElementController;
 use SilverStripe\CMS\Controllers\CMSPageEditController;
 use SilverStripe\Control\Controller;
@@ -13,7 +14,6 @@
 use SilverStripe\Core\Manifest\ModuleResourceLoader;
 use SilverStripe\Forms\CheckboxField;
 use SilverStripe\Forms\DropdownField;
-use SilverStripe\Forms\FieldGroup;
 use SilverStripe\Forms\FieldList;
 use SilverStripe\Forms\HiddenField;
 use SilverStripe\Forms\NumericField;
@@ -259,13 +259,11 @@ public function getCMSFields()
             $fields->removeByName('ShowTitle');
             $fields->replaceField(
                 'Title',
-                FieldGroup::create(
-                    TextField::create('Title', ''),
+                TextCheckboxGroupField::create(
+                    TextField::create('Title', _t(__CLASS__ . '.TitleLabel', 'Title (not displayed unless specified)')),
                     CheckboxField::create('ShowTitle', _t(__CLASS__ . '.ShowTitleLabel', 'Displayed'))
                 )
                     ->setName('TitleAndDisplayed')
-                    ->setTemplate(__CLASS__ . '\\FieldGroup')
-                    ->setTitle(_t(__CLASS__ . '.TitleLabel', 'Title (not displayed unless specified)'))
             );
 
             // Rename the "Main" tab

tests/Forms/TextCheckboxGroupFieldTest.php

@@ -0,0 +1,49 @@
+<?php
+
+namespace DNADesign\Elemental\Tests\Forms;
+
+use DNADesign\Elemental\Forms\TextCheckboxGroupField;
+use SilverStripe\Dev\SapphireTest;
+use SilverStripe\Forms\CheckboxField;
+use SilverStripe\Forms\CompositeField;
+use SilverStripe\Forms\TextField;
+
+class TextCheckboxGroupFieldTest extends SapphireTest
+{
+    /**
+     * @var TextCheckboxGroupField
+     */
+    protected $field;
+
+    protected function setUp()
+    {
+        parent::setUp();
+
+        $this->field = new TextCheckboxGroupField(
+            new TextField('HelloWorld'),
+            new CheckboxField('Display')
+        );
+    }
+
+    public function testFieldIsAssignedFirstFieldsTitleInConstructor()
+    {
+        $this->assertSame('Hello World', $this->field->Title());
+    }
+
+    public function testFieldReturnsCompositeFieldTemplateOnReadonlyTransformation()
+    {
+        $this->assertSame(
+            TextCheckboxGroupField::class,
+            $this->field->getTemplates()[0],
+            'Uses a custom template by default'
+        );
+
+        $readonly = $this->field->performReadonlyTransformation();
+
+        $this->assertSame(
+            CompositeField::class,
+            $readonly->getTemplate(),
+            'Uses CompositeField template for readonly'
+        );
+    }
+}