Fatal error: Call to a member function create() on null

Question

I am trying to create a customer custom attribute in Magento 2, but it's throwing an error.

Fatal error: Call to a member function create() on null in Custom\Setup\InstallData.php on line 47

For creating customer custom attribute I have written the code below.

<?php
namespace Learning\Custom\Setup;


use Magento\Customer\Setup;
use Magento\Framework\Setup\InstallDataInterface;
use Magento\Framework\Setup\ModuleContextInterface;
use Magento\Framework\Setup\ModuleDataSetupInterface;

class InstallData implements InstallDataInterface
{

    /**
     * Customer setup factory
     *
     * @var CustomerSetupFactory
     */
    private $customerSetupFactory;


    /**
     * @var \Magento\Eav\Model\Entity\Attribute\SetFactory
     */
    protected $attributeSetFactory;

    /**
     * @param Setup\CustomerSetupFactory $customerSetupFactory
     */
    public function __construct(\Magento\Customer\Setup\CustomerSetupFactory $customerSetupFactory)
    {
        $this->customerSetupFactory = $customerSetupFactory;
    }

    /**
     * {@inheritdoc}
     * @SuppressWarnings(PHPMD.ExcessiveMethodLength)
     */
    public function install(ModuleDataSetupInterface $setup, ModuleContextInterface $context)
    {
        /** @var CustomerSetup $customerSetup */
        $customerSetup = $this->customerSetupFactory->create(['setup' => $setup]);

        $customerEntity = $customerSetup->getEavConfig()->getEntityType('customer');
        $attributeSetId = $customerEntity->getDefaultAttributeSetId();

        /** @var $attributeSet AttributeSet */
        $attributeSet = $this->attributeSetFactory->create();
        $attributeGroupId = $attributeSet->getDefaultGroupId($attributeSetId);


        $customerSetup->addAttribute(Customer::ENTITY, 'custom_name', [
            'type' => 'varchar',
            'label' => 'Custom Name',
            'input' => 'text',
            'class' => '',
            'source' => '',
            'global' => \Magento\Eav\Model\Entity\Attribute\ScopedAttributeInterface::SCOPE_GLOBAL,
            /*Scope of your attribute */
            'required' => false,
            'visible' => true,
            'user_defined' => true,
            'position' =>999,
            'system' => 0,
        ]);

        $attribute = $customerSetup->getEavConfig()->getAttribute(Customer::ENTITY, 'approved_attribute')
            ->addData([
                'attribute_set_id' => $attributeSetId,
                'attribute_group_id' => $attributeGroupId,
                'used_in_forms' => ['adminhtml_customer'],
            ]);

        $attribute->save();
    }


}

Could you please suggest where the problem might be?

Answer 1

Check my below suggestion code.

<?php
namespace Learning\Custom\Setup;

use Magento\Customer\Setup\CustomerSetupFactory;
use Magento\Customer\Model\Customer;
use Magento\Eav\Model\Entity\Attribute\Set as AttributeSet;
use Magento\Eav\Model\Entity\Attribute\SetFactory as AttributeSetFactory;
use Magento\Framework\Setup\InstallDataInterface;
use Magento\Framework\Setup\ModuleContextInterface;
use Magento\Framework\Setup\ModuleDataSetupInterface;

class InstallData implements InstallDataInterface
{

    /**
     * @var CustomerSetupFactory
     */
    protected $customerSetupFactory;

    /**
     * @var AttributeSetFactory
     */
    private $attributeSetFactory;

    /**
     * @param CustomerSetupFactory $customerSetupFactory
     * @param AttributeSetFactory $attributeSetFactory
     */
    public function __construct(
        CustomerSetupFactory $customerSetupFactory,
        AttributeSetFactory $attributeSetFactory
    ) {
        $this->customerSetupFactory = $customerSetupFactory;
        $this->attributeSetFactory = $attributeSetFactory;
    }


    /**
     * {@inheritdoc}
     * @SuppressWarnings(PHPMD.ExcessiveMethodLength)
     */
    public function install(ModuleDataSetupInterface $setup, ModuleContextInterface $context)
    {
        /** @var CustomerSetup $customerSetup */
        $customerSetup = $this->customerSetupFactory->create(['setup' => $setup]);


        $customerEntity = $customerSetup->getEavConfig()->getEntityType('customer');

        $attributeSetId = $customerEntity->getDefaultAttributeSetId();


        /** @var $attributeSet AttributeSet */
        $attributeSet = $this->attributeSetFactory->create();

        $attributeGroupId = $attributeSet->getDefaultGroupId($attributeSetId);



        $customerSetup->addAttribute(Customer::ENTITY, 'custom_name', [
            'type' => 'varchar',
            'label' => 'Custom Name',
            'input' => 'text',
            'class' => '',
            'source' => '',
            'global' => \Magento\Eav\Model\Entity\Attribute\ScopedAttributeInterface::SCOPE_GLOBAL,
            /*Scope of your attribute */
            'required' => false,
            'visible' => true,
            'user_defined' => true,
            'position' =>999,
            'system' => 0,
        ]);

        $attribute = $customerSetup->getEavConfig()->getAttribute(Customer::ENTITY, 'approved_attribute')
            ->addData([
                'attribute_set_id' => $attributeSetId,
                'attribute_group_id' => $attributeGroupId,
                'used_in_forms' => ['adminhtml_customer'],
            ]);

        $attribute->save();
    }


}

Answer 2

I assume this is line 47: $attributeSet = $this->attributeSetFactory->create();.
If it is, then the problem is that $this->attributeSetFactory is alwasy null. You declared it in your class, but it never receives a value.
You should change the constructor to look like this:

public function __construct(
    \Magento\Customer\Setup\CustomerSetupFactory $customerSetupFactory,
    \Magento\Eav\Model\Entity\Attribute\SetFactory $attributeSetFactory
) {
    $this->customerSetupFactory = $customerSetupFactory;
    $this->attributeSetFactory  = $attributeSetFactory;
}

And clear var/generation.