Magento 2 - It is possible to create a select with optgroup using \Magento\Framework\Data\Form\Element\::addField?

Question

As the title says,

Looking at Magento\Framework\Data\Form\Element\Select looks like it does but i cant figure out the array? that i have to pass to my addField(id, type, [name, label, options]);

Answer 1

Try this solution:

$fieldset->addField(
    'test',
    'select',
    [
        'label' => __('Test'),
        'name' => 'test',
        'required' => true,
        'values' => [
            [
                'label' => 'optgroup 1',
                'value' => [
                    [
                        'label' => 'in opt group 1-1',
                        'value' => 'value 1-1'
                    ],
                    [
                        'label' => 'in opt group 1-2',
                        'value' => 'value 1-2'
                    ],
                    [
                        'label' => 'in opt group 1-3',
                        'value' => 'value 1-3'
                    ],
                ]
            ],
            [
                'label' => 'optgroup 2',
                'value' => [
                    [
                        'label' => 'in opt group 2-1',
                        'value' => 'value 2-1'
                    ],
                    [
                        'label' => 'in opt group 2-2',
                        'value' => 'value 2-2'
                    ],
                    [
                        'label' => 'in opt group 2-3',
                        'value' => 'value 2-3'
                    ],
                ]
            ],
            [
                'label' => 'optgroup 3',
                'value' => [
                    [
                        'label' => 'in opt group 3-1',
                        'value' => 'value 3-1'
                    ],
                    [
                        'label' => 'in opt group 3-2',
                        'value' => 'value 3-2'
                    ],
                    [
                        'label' => 'in opt group 3-3',
                        'value' => 'value 3-3'
                    ],
                ]
            ]
        ]
    ]
);

The result looks as follows: