# Conditional fields - Optionline 1.x documentation

> Show a field only when another field's value is, isn't, contains something, or is filled in; checked again on the server.

> [!NOTE]
> This is part of **Optionline Pro**.

A conditional field only shows when other fields have certain values: a **Card message** once **Gift box** is ticked, an **Engraving font** once something is typed in **Engraving**, a **Custom size** only when **Size** is "Custom".

![A conditional field in the field's settings](https://storage.extendiment.com/media/1011/screenshot-4-4eff3b81.png)

## Setting it up

In the field's box, find **Show this field**:

1. Choose **Only when all of these match** or **Only when any of these match**.
2. A rule appears. Choose the **field** it looks at, the **condition**, and the **value**.
3. **Add rule** for more.
4. Update the product (or the group).

**Always** (the default) shows the field whatever the other fields say.

| Condition | Matches when the other field… |
|---|---|
| **is** | has exactly the value. For a dropdown, radio buttons or swatches, the chosen choice's name; for checkboxes, one of the ticked choices. |
| **is not** | doesn't have the value (an empty field counts as "not"). |
| **contains** | has the value somewhere in it: in the text, or in a chosen choice's name. |
| **is filled in** | has any value: text typed, a choice made, a box ticked, a file chosen. |
| **is empty** | has no value. |

Case and spaces around the value don't matter: "gift box" matches "Gift box".

## On the product page

The field appears and disappears as the customer chooses, and the live total only counts fields that show. A hidden field isn't sent with the form.

## On the server

When the product is added to the cart, the store works the conditions out again from what was sent, whatever the browser did:

- A field that doesn't show is **never required**, **never stored** on the cart line and **never charged**, even if a value for it was sent.
- A field that doesn't show counts as **empty** for other fields' conditions, so chains work: the card's font only shows when the card shows.
- Conditions that point back at their own field (directly or through others) never show the field.

## Without Optionline Pro

If Optionline Pro is deactivated, conditional fields are kept but not shown in your shop, rather than shown (and required, or charged) for everyone. They're back when Pro is active again.

Source: https://extendiment.com/plugins/optionline/docs/1.x/conditional-fields