Missing required argument $modifiers of Magento\Ui\DataProvider\Modifier\Pool

Question

I have created a custom module. In which I want to use data modifier. I have written this code but it gives the following error:

Missing required argument $modifiers of Magento\Ui\DataProvider\Modifier\Pool

My Code is Like di.xml

<virtualType name="Vendor\Module\Ui\DataProvider\Customer\Form\Modifier\Pool" type="Magento\Ui\DataProvider\Modifier\Pool">
    <arguments>
        <argument name="modifiers" xsi:type="array">
            <item name="customer" xsi:type="array">
                <item name="class" xsi:type="string">Vendor\Module\Ui\DataProvider\Customer\Form\Modifier\Customer</item>
                <item name="sortOrder" xsi:type="number">120</item>
            </item>
        </argument>
    </arguments>
</virtualType>
<type name="Vendor\Module\Ui\DataProvider\Customer\Form\Modifier\CustomerDataProvider">
    <arguments>
        <argument name="pool" xsi:type="object">Vendor\Module\Ui\DataProvider\Customer\Form\Modifier\Pool</argument>
    </arguments>
</type>
<type name="Vendor\ModuleUi\DataProvider\Customer\Form\Modifier\Customer">
    <arguments>
        <argument name="scopeName" xsi:type="string">customer_form.customer_form</argument>
    </arguments>
</type>

CustomerDataProvider.php

namespace Vendor\Module\Ui\DataProvider\Customer\Form;

use Magento\Customer\Model\ResourceModel\Customer\CollectionFactory;
use Magento\Ui\DataProvider\AbstractDataProvider;
use Magento\Ui\DataProvider\Modifier\ModifierInterface;
use Magento\Ui\DataProvider\Modifier\PoolInterface;
/**
 * DataProvider for product edit form
 */
class CustomerDataProvider extends AbstractDataProvider
{
    /**
     * @var PoolInterface
     */
    private $pool;
    /**
     * @param string $name
     * @param string $primaryFieldName
     * @param string $requestFieldName
     * @param CollectionFactory $collectionFactory
     * @param PoolInterface $pool
     * @param array $meta
     * @param array $data
     */
    public function __construct(
        $name,
        $primaryFieldName,
        $requestFieldName,
        CollectionFactory $collectionFactory,
        PoolInterface $pool,
        array $meta = [],
        array $data = []
    ) {
        parent::__construct($name, $primaryFieldName, $requestFieldName, $meta, $data);
        $this->collection = $collectionFactory->create();
        $this->pool = $pool;
    }
    /**
     * {@inheritdoc}
     */
    public function getData()
    {
        /** @var ModifierInterface $modifier */
        foreach ($this->pool->getModifiersInstances() as $modifier) {
            $this->data = $modifier->modifyData($this->data);
        }
        return $this->data;
    }
    /**
     * {@inheritdoc}
     */
    public function getMeta()
    {
        $meta = parent::getMeta();
        /** @var ModifierInterface $modifier */
        foreach ($this->pool->getModifiersInstances() as $modifier) {
            $meta = $modifier->modifyMeta($meta);
        }
        return $meta;
    }
}

modifier file Customer.php

<?php
namespace Vendor\Module\Ui\DataProvider\Customer\Form\Modifier;

use Magento\Ui\DataProvider\Modifier\ModifierInterface;
/**
 * Class Prices
 * @SuppressWarnings(PHPMD.CouplingBetweenObjects)
 */
class Customer implements ModifierInterface
{
    /**
     * {@inheritdoc}
     */
    public function modifyMeta(array $meta)
    {
        return $meta;
    }

    /**
     * {@inheritdoc}
     */
    public function modifyData(array $data)
    {
        return $data;
    }
}

I can't find where it is missing arguments. Please correct way to add modifiers.

Note - I am adding this modifier for customer edit form

Answer 1

Try with following updated code.

namespace Vendor\Module\Ui\DataProvider\Customer\Form;

use Magento\Customer\Model\ResourceModel\Customer\CollectionFactory;
use Magento\Ui\DataProvider\AbstractDataProvider;
use Magento\Ui\DataProvider\Modifier\ModifierInterface;
use Magento\Ui\DataProvider\Modifier\PoolInterface;
/**
 * DataProvider for product edit form
 */
class CustomerDataProvider extends AbstractDataProvider implements PoolInterface
{

    protected $modifiers = [];

    protected $modifiersInstances = [];

    /**
     * @param string $name
     * @param string $primaryFieldName
     * @param string $requestFieldName
     * @param CollectionFactory $collectionFactory
     * @param PoolInterface $pool
     * @param array $meta
     * @param array $data
     */
    public function __construct(
        $name,
        $primaryFieldName,
        $requestFieldName,
        CollectionFactory $collectionFactory,
        array $meta = [],
        array $data = []
    ) {
        parent::__construct($name, $primaryFieldName, $requestFieldName, $meta, $data);
        $this->collection = $collectionFactory->create();
    }
    /**
     * {@inheritdoc}
     */
    public function getData()
    {
        /** @var ModifierInterface $modifier */
        foreach ($this->pool->getModifiersInstances() as $modifier) {
            $this->data = $modifier->modifyData($this->data);
        }
        return $this->data;
    }
    /**
     * {@inheritdoc}
     */
    public function getMeta()
    {
        $meta = parent::getMeta();
        /** @var ModifierInterface $modifier */
        foreach ($this->pool->getModifiersInstances() as $modifier) {
            $meta = $modifier->modifyMeta($meta);
        }
        return $meta;
    }  

    /**
     * Retrieve modifiers
     *
     * @return array
     */
    public function getModifiers()
    {
        return $this->modifiers;
    }

    /**
     * Retrieve modifiers instantiated
     *
     * @return ModifierInterface[]
     * @throws LocalizedException
     */
    public function getModifiersInstances()
    {
        if ($this->modifiersInstances) {
            return $this->modifiersInstances;
        }

        foreach ($this->modifiers as $modifier) {
            if (empty($modifier['class'])) {
                throw new LocalizedException(__('Parameter "class" must be present.'));
            }

            if (empty($modifier['sortOrder'])) {
                throw new LocalizedException(__('Parameter "sortOrder" must be present.'));
            }

            $this->modifiersInstances[$modifier['class']] = $this->factory->create($modifier['class']);
        }

        return $this->modifiersInstances;
    }
}

Answer 2

Your dataprovider namespace is wrong replace following line in your di.xml

<type name="Vendor\Module\Ui\DataProvider\Customer\Form\Modifier\CustomerDataProvider">

with

<type name="Vendor\Module\Ui\DataProvider\Customer\Form\CustomerDataProvider">