magento 2 in category multi select attribute in option is not show?

Question

:InstallData

<?php
namespace Vender\Extension\Setup;

use Magento\Eav\Setup\EavSetup;
use Magento\Eav\Setup\EavSetupFactory;
use Magento\Framework\Setup\InstallDataInterface;
use Magento\Framework\Setup\ModuleContextInterface;
use Magento\Framework\Setup\ModuleDataSetupInterface;
use Magento\Catalog\Model\Category\Attribute\Backend\Sortby as SortbyBackendModel;
use Magento\Catalog\Model\Category\Attribute\Source\Sortby;

class InstallData implements InstallDataInterface
{
    private $eavSetupFactory;
   
    public function __construct(EavSetupFactory $eavSetupFactory)
    {
        $this->eavSetupFactory = $eavSetupFactory;
    }

    
    public function install(ModuleDataSetupInterface $setup, ModuleContextInterface $context)
    {
       
        $eavSetup = $this->eavSetupFactory->create(['setup' => $setup]);
      
       
        $eavSetup->addAttribute(
            \Magento\Catalog\Model\Category::ENTITY,
            'choosesubcategoryslider',
            [
                'group' => 'Choose Sub Category',
                'label' => 'Choose Sub Category Slider',
                'type'  => 'int',
                'input' => 'multiselect',
                'backend' => 'Vender\Extension\Model\Category\Attribute\Backend\Choosesubcategoryslider',
                'source' => 'Vender\Extension\Model\Config\Source\Choosesubcategoryslider',
                'global' => \Magento\Eav\Model\Entity\Attribute\ScopedAttributeInterface::SCOPE_STORE,
                'required' => false,
                'sort_order' => 20
            ]
        );
    }
}

backend:Vender\Extension\Model\Category\Attribute\Backend

<?php


namespace Vender\Extension\Model\Category\Attribute\Backend;

class Choosesubcategoryslider extends \Magento\Eav\Model\Entity\Attribute\Backend\AbstractBackend
{
    public function beforeSave($object)
    {
        $attributeCode = $this->getAttribute()->getName();
        if ($attributeCode == 'choosesubcategoryslider') {
            $data = $object->getData($attributeCode);
            if (!is_array($data)) {
                $data = [];
            }
            $object->setData($attributeCode, implode(',', $data) ?: null);
        }
        if (!$object->hasData($attributeCode)) {
            $object->setData($attributeCode, null);
        }
        return $this;
    }

    public function afterLoad($object)
    {
        $attributeCode = $this->getAttribute()->getName();
        if ($attributeCode == 'choosesubcategoryslider') {
            $data = $object->getData($attributeCode);
            if ($data) {
                if (!is_array($data)) {
                    $object->setData($attributeCode, explode(',', $data));
                } else {
                    $object->setData($attributeCode, $data);
                }
            }
        }
        return $this;
    }
}

sorce:Vender\Extension\Model\Config\Source

<?php
namespace Vender\Extension\Model\Config\Source;

class Choosesubcategoryslider extends \Magento\Eav\Model\Entity\Attribute\Source\AbstractSource
{
    /**
     * Catalog config
     *
     * @var \Magento\Catalog\Model\Config
     */
    protected $_catalogConfig;

    /**
     * Construct
     *
     * @param \Magento\Catalog\Model\Config $catalogConfig
     */
    public function __construct(\Magento\Catalog\Model\Config $catalogConfig)
    {
        $this->_catalogConfig = $catalogConfig;
    }

    /**
     * Retrieve Catalog Config Singleton
     *
     * @return \Magento\Catalog\Model\Config
     */
    protected function _getCatalogConfig()
    {
        return $this->_catalogConfig;
    }

    /**
     * {@inheritdoc}
     */
    public function getAllOptions()
    {
        if ($this->_options === null) {
            $this->_options = [
                ['label' => __('Label1'), 'value' => 'value1'],
                ['label' => __('Label2'), 'value' => 'value2'],
                ['label' => __('Label3'), 'value' => 'value3'],
                ['label' => __('Label4'), 'value' => 'value4']

            ];

        }
        return $this->_options;
    }
}

category_form.xml path:view\adminhtml\ui_component\category_form.xml

<?xml version="1.0" encoding="UTF-8"?>
<form xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
      xsi:noNamespaceSchemaLocation="urn:magento:module:Magento_Ui:etc/ui_configuration.xsd">
    <fieldset name="choossubcategory">
        <argument name="data" xsi:type="array">
            <item name="config" xsi:type="array">
                <item name="label" xsi:type="string" translate="true">Choose Sub Category</item>
                <item name="collapsible" xsi:type="boolean">true</item>
                <item name="sortOrder" xsi:type="number">80</item>
            </item>
        </argument>
        <field name="choosesubcategoryslider">
            <argument name="data" xsi:type="array">
                    <item name="config" xsi:type="array">
                    <item name="sortOrder" xsi:type="number">20</item>
                    <item name="dataType" xsi:type="string">string</item>
                    <item name="formElement" xsi:type="string">multiselect</item>
                    <item name="source" xsi:type="string">category</item>
                    <item name="prefer" xsi:type="string">toggle</item>
                    <item name="valueMap" xsi:type="array">
                        <item name="true" xsi:type="string">1</item>
                        <item name="false" xsi:type="string">0</item>
                    </item>
                    <item name="validation" xsi:type="array">
                        <item name="required-entry" xsi:type="boolean">false</item>
                    </item>
                    <item name="default" xsi:type="string">0</item>
                    <item name="label" xsi:type="string" translate="true">Choose Sub Category Slider</item>
                </item>
            </argument>
        </field>
</form>

Answer 1

Magento 2 programmatically Category Multiselect Attributes Create

Step -1 Create File App\Code\Vendor\Extension\Setup\InstallData.php

<?php
namespace Vendor\Extension\Setup;

use Magento\Eav\Setup\EavSetup;
use Magento\Eav\Setup\EavSetupFactory;
use Magento\Framework\Setup\InstallDataInterface;
use Magento\Framework\Setup\ModuleContextInterface;
use Magento\Framework\Setup\ModuleDataSetupInterface;
use Magento\Catalog\Model\Category\Attribute\Backend\Sortby as SortbyBackendModel;
use Magento\Catalog\Model\Category\Attribute\Source\Sortby;

class InstallData implements InstallDataInterface
{
    private $eavSetupFactory;
   
    public function __construct(EavSetupFactory $eavSetupFactory)
    {
        $this->eavSetupFactory = $eavSetupFactory;
    }

    
    public function install(ModuleDataSetupInterface $setup, ModuleContextInterface $context)
    {
       
        $eavSetup = $this->eavSetupFactory->create(['setup' => $setup]);
      
       
        $eavSetup->addAttribute(
            \Magento\Catalog\Model\Category::ENTITY,
            'choosesubcategoryslider',
            [
                'group' => 'Choose Sub Category',
                'label' => 'Choose Sub Category Slider',
                'type'  => 'text',
                'input' => 'multiselect',
                'backend' => 'Vendor\Extension\Model\Category\Attribute\Backend\Choosesubcategoryslider',
                'source' => 'Vendor\Extension\Model\Config\Source\Choosesubcategoryslider',
                'global' => \Magento\Eav\Model\Entity\Attribute\ScopedAttributeInterface::SCOPE_STORE,
                'required' => false,
                'sort_order' => 20
            ]
        );
    }
}

Step -2 Create File App\code\Vendor\Extension\Model\Category\Attribute\Backend\Choosesubcategoryslider.php

<?php

namespace Vendor\Extension\Model\Category\Attribute\Backend;

class Choosesubcategoryslider extends \Magento\Eav\Model\Entity\Attribute\Backend\AbstractBackend
{
    public function beforeSave($object)
    {
        $attributeCode = $this->getAttribute()->getName();
        if ($attributeCode == 'choosesubcategoryslider') {
            $data = $object->getData($attributeCode);
            if (!is_array($data)) {
                $data = [];
            }
            $object->setData($attributeCode, implode(',', $data) ?: null);
        }
        if (!$object->hasData($attributeCode)) {
            $object->setData($attributeCode, null);
        }
        return $this;
    }

    public function afterLoad($object)
    {
        $attributeCode = $this->getAttribute()->getName();
        if ($attributeCode == 'choosesubcategoryslider') {
            $data = $object->getData($attributeCode);
            if ($data) {
                if (!is_array($data)) {
                    $object->setData($attributeCode, explode(',', $data));
                } else {
                    $object->setData($attributeCode, $data);
                }
            }
        }
        return $this;
    }
}

Step -3 create file App\code\Vendor\Extension\Model\Config\Source\Choosesubcategoryslider.php

<?php
namespace Vendor\Extension\Model\Config\Source;

class Choosesubcategoryslider extends \Magento\Eav\Model\Entity\Attribute\Source\AbstractSource
{
    /**
     * Catalog config
     *
     * @var \Magento\Catalog\Model\Config
     */
    protected $_catalogConfig;

    /**
     * Construct
     *
     * @param \Magento\Catalog\Model\Config $catalogConfig
     */
    public function __construct(\Magento\Catalog\Model\Config $catalogConfig)
    {
        $this->_catalogConfig = $catalogConfig;
    }

    /**
     * Retrieve Catalog Config Singleton
     *
     * @return \Magento\Catalog\Model\Config
     */
    protected function _getCatalogConfig()
    {
        return $this->_catalogConfig;
    }

    /**
     * {@inheritdoc}
     */
    public function getAllOptions()
    {
        if ($this->_options === null) {
            $this->_options = [
                ['label' => __('Label1'), 'value' => 'value1'],
                ['label' => __('Label2'), 'value' => 'value2'],
                ['label' => __('Label3'), 'value' => 'value3'],
                ['label' => __('Label4'), 'value' => 'value4']

            ];

        }
        return $this->_options;
    }
}

Step-4 Create file app\code\Vendor\Extension\view\adminhtml\ui_component\category_form.xml

<?xml version="1.0" encoding="UTF-8"?>
<form xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
      xsi:noNamespaceSchemaLocation="urn:magento:module:Magento_Ui:etc/ui_configuration.xsd">
    <fieldset name="choossubcategory">
        <argument name="data" xsi:type="array">
            <item name="config" xsi:type="array">
                <item name="label" xsi:type="string" translate="true">Choose Sub Category</item>
                <item name="collapsible" xsi:type="boolean">true</item>
                <item name="sortOrder" xsi:type="number">80</item>
            </item>
        </argument>
        <field name="choosesubcategoryslider">
            <argument name="data" xsi:type="array">
                <item name="options" xsi:type="object">Vendor\Extension\Model\Config\Source\Choosesubcategoryslider</item>
                <item name="config" xsi:type="array">
                    <item name="sortOrder" xsi:type="number">60</item>
                    <item name="dataType" xsi:type="string">string</item>
                    <item name="formElement" xsi:type="string">multiselect</item>
                    <item name="label" xsi:type="string" translate="true">Choose Sub Category Slider1</item>
                </item>
            </argument>
        </field>
    </fieldset>
</form>

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