Develop a module to create custom attributes in categories, not in setup

Question

I want to create a module like the default module of Magento: Product Attributes in admin, located in Stores -> Attributes -> Product, but for categories, add custom attributes to categories from an admin module. I know how to create a module for the admin, I created a form, but I don't know how to save all the data and save the new attribute.

I read this post: Magento2 Create eav_attribute for catalog but here the attribute is created inside the Setup.

Answer 1

I didn't try any sample but i think with this code will be work

Magento 2.0.x:

With Magento 2.1.x, please read more info in next to answer.

in your controller:

protected $_evaSetup;

public function __construct(.....,
     \Magento\Eav\Setup\EavSetupFactory $eavSetupFactory
){
      parent::__construct($context);
      .....
      $this->_abc = $eavSetupFactory;    
}
public function execute(){
      $categorySetup = $this->_evaSetup->create(['setup' => $setup]);

    /**
     * Add attributes to the eav/attribute
     */
    $entityTypeId = $categorySetup->getEntityTypeId(\Magento\Catalog\Model\Category::ENTITY);
    $attributeSetId = $categorySetup->getDefaultAttributeSetId($entityTypeId);
    $categorySetup->addAttribute(
    \Magento\Catalog\Model\Category::ENTITY, 'my_attribute', [
         'type' => 'int',
         'label' => 'My Atrribute ',
         'input' => 'select',
         'source' => 'Magento\Eav\Model\Entity\Attribute\Source\Boolean',
         'required' => false,
         'sort_order' => 100,
         'global' => \Magento\Eav\Model\Entity\Attribute\ScopedAttributeInterface::SCOPE_STORE,
         'group' => 'General Information',
    ]);
     $idg =  $categorySetup->getAttributeGroupId($entityTypeId, attributeSetId, 'General Information');
     $categorySetup->addAttributeToGroup(
           $entityTypeId,
           $attributeSetId,
           $idg,
          'my_attribute',
          46);
}

http://www.ibnab.com/en/blog/magento-2/magento-2-add-custom-eav-attribute-to-category-or-customer

Answer 2

The above solution is not enough to show the Category attribute in the admin Category Edit page. This will create the category attribute, but we will not see in the admin edit page. You need to add view/adminhtml/ui_component/category_form.xml and add the code for the custom field. More info on the blog: http://mage-simplified.blogspot.com/2016/07/magento-210-category-custom-attribute.html

<?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="content">
        <field name="sample_module_field">
            <argument name="data" xsi:type="array">
                <item name="config" xsi:type="array">
                    <item name="sortOrder" xsi:type="number">110</item>
                    <item name="dataType" xsi:type="string">string</item>
                    <item name="formElement" xsi:type="string">input</item>
                    <item name="label" xsi:type="string" translate="true">Custom Field</item>
                </item>
            </argument>
        </field>
    </fieldset>
</form>