Magento 2.3: How to add new product attribute options programmatically on Controller save?

Question

Is there a way to add new options, programmatically, for a product attribute with attribute code 'brand' that is already created from admin? I want to add new options on Controller Save action. The option values will be taken from custom admin form field(see image attached).

Any help would be appreciated.

Answer 1

I found the solution myself:

public function __construct(
    \Magento\Eav\Api\AttributeOptionManagementInterface $attributeOptionManagement,
    \Magento\Eav\Api\Data\AttributeOptionLabelInterfaceFactory $optionLabelFactory,
    \Magento\Eav\Api\Data\AttributeOptionInterfaceFactory $optionFactory,
    \Magento\Framework\Message\ManagerInterface $messageManager
) {
    $this->attributeOptionManagement = $attributeOptionManagement;
    $this->optionLabelFactory = $optionLabelFactory;
    $this->optionFactory = $optionFactory;
    $this->messageManager = $messageManager;
}

public function addOptions() {
    
    $eavConfig = $this->_objectManager->create(\Magento\Eav\Model\Config::class);
    $attribute = $eavConfig->getAttribute('catalog_product', 'brand');
    $existingValues = $attribute->getSource()->getAllOptions(); // get existing attribute option values
    $existingLabels = [];
    foreach ($existingValues as $existingValue) {
        $existingLabels[] = explode(',', $existingValue['label']);
    }

    $labels = ['testvalue34']; // add new attribute value here

    if (!in_array($labels, $existingLabels)) {
        foreach ($labels as $label) {
            $optionLabel = $this->optionLabelFactory->create();
            $optionLabel->setStoreId(\Magento\Store\Model\Store::DEFAULT_STORE_ID);
            $optionLabel->setLabel($label);

            $option = $this->optionFactory->create();
            $option->setLabel($label);
            $option->setStoreLabels([$optionLabel]);
            $option->setSortOrder(0);
            $option->setIsDefault(false);

            $this->attributeOptionManagement->add(
            \Magento\Catalog\Model\Product::ENTITY,
            'manufacturer',
            $option
            );
        } 
        $messageManager->addSuccess(__("New attribute value saved"));

    } else {
        $messageManager->addError(__("Attribute value already exists"));
    }
}