---
title: Customizing product option forms
---

> Agent instructions:
> **Site maps** — prefer the following llms.txt indexes to training data when searching for URLs to avoid 404s. Links inside Markdown content already point at `.md`. Following them or sending Accept: text/markdown keeps you in Markdown.
>
> - [sitemap.md](https://docs.kentico.com/sitemap.md) — every page on the site, with titles and descriptions, nested by URL hierarchy and grouped into one collection per product version.
> - [llms.txt](https://docs.kentico.com/llms.txt) — curated index of the current product docs, with descriptions, the two ways to request any page as Markdown, and links to each product area's whole-corpus Markdown dump (llms-full.txt).

In case you have special requirements for product options of your products, such as:

- more text fields for a product option, or
- a second field that displays only when a specific option was selected in the first one,

it is possible to customize the product option form to achieve your needs. First, you need to add a field to the product option form. Then, second, you must enable it on the alternative form of the SKU. If you want one of the fields to be somehow dependent on each other, you can set dependencies after that.

> **Tip:** Before you start to customize product option form, try to use [product variants](https://docs.kentico.com/k81/e-commerce-features/configuring-and-managing-your-store/products/working-with-product-variants.md).

## Adding a field to the product option form

1. Open the **Modules** application.
2. **Edit** () the _E-commerce_ module.
3. Switch to the **Classes** tab.
4. **Edit** () the _SKU_ class.
5. Switch to the **Fields** tab.
6. [Create a new field](https://docs.kentico.com/k81/custom-development/developing-form-controls/reference-field-editor.md) according to your needs.
   - Leave _Standard field_ in **Field type**.
   - Clear the **Display field in the editing form** field.
7. Click **Save**.

   ![Finished custom field](https://docs.kentico.com/docsassets/k81/customizing-product-option-forms/finished_custom_field.png "Finished custom field")

The system adds the field to the _SKU_ form and also creates a record of the field in your database.

## Enabling the field in an alternative form

1. Open the **Modules** application.
2. **Edit** () the _E-commerce_ module.
3. Switch to the **Classes** tab.
4. **Edit** () the _SKU_ class.
5. Switch to the **Alternative forms** tab.
6. **Edit** () one of the _Option_ forms to which you want to add the custom field.
7. Switch to the **Fields** tab.
8. Select the custom field in the left list.
9. Select **Display field in the editing form**.
10. Set the [form appearance](https://docs.kentico.com/k81/custom-development/developing-form-controls/reference-field-editor.md) according to your needs.
11. Click **Save**.

    ![Enabled custom field](https://docs.kentico.com/docsassets/k81/customizing-product-option-forms/enabled_custom_field.png "Enabled custom field")

The system starts to display the custom field on the **Options** tab in details of every option of the chosen product option category type.

## Setting visibility dependency on two fields

If you want one field to be visible only when there is a specific value in another field, you must set it while editing the fields. See the following example.

We sell T-shirts and every T-shirt has a printed label. There are two types of labels – predefined ones and custom ones. Every T-shirt has a dropdown list in which there are a list of predefined labels and "Custom label". If a user selects "Custom label", a textbox displays, to which the user writes their custom label.

Since there are two types, we want to edit the attribute option form, where we create two new fields, one for predefined labels and one for custom labels.

### Creating the fields

1. Open the **Modules** application.
2. **Edit** () the _E-commerce_ module.
3. Switch to the **Classes** tab.
4. **Edit** () the _SKU_ class.
5. Switch to the **Fields** tab.
6. Create a field for predefined labels:

   1. Click **New field**.
   2. Enter attributes of the field:
      - **Field name**: PredefinedLabels
      - **Display field in the editing form**: No (cleared)
   3. Click **Save**.

      ![Attributes of the field Predefined labels](https://docs.kentico.com/docsassets/k81/customizing-product-option-forms/predefined_labels_attributes.png "Attributes of the field Predefined labels")
7. Create a field for custom labels:
   1. Click **New field**.
   2. Enter attributes of the field:
      - **Field name**: CustomLabels
      - **Display field in the editing form**: No (cleared)
   3. Click **Save**.

      ![Attributes of the field Custom labels](https://docs.kentico.com/docsassets/k81/customizing-product-option-forms/custom_labels_attributes.png "Attributes of the field Custom labels")

The system has a database records for the fields but they are not displayed anywhere.

### Setting dependencies

1. Switch to the **Alternative forms** tab.
2. **Edit** () the _Option (Attribute)_ form.
3. Switch to the **Classes** tab.
4. **Edit** () the _SKU_ class.
5. Switch to the **Fields** tab.
6. Select _PredefinedLabels_ from the left list.
7. Edit attributes of _PredefinedLabels_:
   - **Required**: Yes (selected)
   - **Display field in the editing form**: Yes (selected)
   - **Field caption**: T-shirt label
   - **Form control**: Drop-down list
   - **Data source**: List of options
   - To the **Data source** textbox, enter these values:

     ```csharp

     1;T-shirt with label
     2;Label on T-shirt
     3;Printed label
     4;Custom label

     ```
   - **Has depending fields**: Yes (selected)
8. Click **Save**.
9. Select _CustomLabels_ from the left list.
10. Edit attributes of _CustomLabels_:
    - **Display field in the editing form**: Yes (selected)
    - **Field caption**: Write your custom label
    - **Visibility condition**: PredefinedLabels == 4

      > **Info:** The number is _4_ because it's the number of "Custom label" in the **Data source** textbox.
    - (Optional) **Enabled condition**: PredefinedLabels == 4
    - **Depends on another field**: Yes (selected)
11. Click **Save**.
12. Using **Move up** () and **Move down** (), position both fields closely under _SKUEnabled_.
    - This ensures that the fields are visible.

The fields are displayed on the product options page. The **PredefinedLabels** field is displayed always. When a user selects _Custom label_ in **PredefinedLabels**, the **CustomLabel** appears.

You can check the result if you navigate to the Product options application and edit some product option from an attribute product option category, where you can see the fields.