Howto add attribute to multiple attribute sets programmatically in magento2?

Question

Subject. Which classes I need to use to deal with it?

It seems that I don't understand much about how attributes work.

For example I use this code to add attribute to one attribute set and to one attribute group:

/** @var $attribute \Magento\Catalog\Model\ResourceModel\Eav\Attribute */
$attribute->setAttributeSetId($attributeSetId);
$attribute->setAttributeGroupId($groupId);

Thanks.

UPD: My problem not in 'how to get attribute set ids', I already have a few. I'm more interesting in the part of code where // add your code here. I think if we set the value by method $attribute->setAttributeSetId(), it override previous attribute set link in the attribute. I'm trying to find some solution like $attribute->addAttributeSetId() or $attribute->setAttributeSetIds(), but there are none

UPD2: Found the way: Using \Magento\Eav\Api\AttributeManagementInterface->assign(). Full code in answer below.

Answer 1

Found a simple solution.

my method:

public function assignAttributeToSets($attribute_code, $attribute_set_ids) {
    foreach ($attribute_set_ids as $set_id) {
        $group_id = $this->config->getAttributeGroupId($set_id, 'Product Details');
        $this->attributeManagement->assign(
            'catalog_product',  // entity type code
            $set_id,
            $group_id,
            $attribute_code,
            null
        );
    }
}

And constructor:

public function __construct(
    \Magento\Catalog\Model\Config $config,
    \Magento\Eav\Api\AttributeManagementInterface $attributeManagement
)
{
    $this->config = $config;
    $this->attributeManagement = $attributeManagement;
}

Answer 2

Try following way:

/**
 * EAV setup factory
 *
 * @var \Magento\Eav\Setup\EavSetupFactory
 */
private $eavSetupFactory;

/**
 * Init
 *
 * @param \Magento\Eav\Setup\EavSetupFactory $eavSetupFactory
 */
public function __construct(\Magento\Eav\Setup\EavSetup\Factory $eavSetupFactory)
{
    $this->eavSetupFactory = $eavSetupFactory;
}

And now

/** @var \Magento\Eav\Setup\EavSetup $eavSetup */
$eavSetup = $this->eavSetupFactory->create(['setup' => $setup]);

$entityTypeId = $eavSetup->getEntityTypeId(\Magento\Catalog\Model\Product::ENTITY);
$attributeSetIds = $eavSetup->getAllAttributeSetIds($entityTypeId);
foreach ( $attributeSetIds as $attributeSetId) {
    // add your code here
}

[Update]

Check following class

Magento/Eav/Setup/EavSetup.php

Here you can see your desire method like

getAttributeSetId()
getAttributeGroupId()

So using previous example you can access these method using $eavSetup object. like

$eavSetup->getAttributeSetId($entityTypeId, $setId)
$eavSetup->getAttributeGroupId($entityTypeId, $setId, $groupId)

For update attribute set use

updateAttributeSet()