# Conditional Logic Forms

Source: https://docs.astalty.com.au/guide/forms/conditional-logic-forms

> Show, hide, or require form fields based on earlier answers.

Astalty Premium - This feature is part of the Astalty Premium plan. See What Premium includes.

## Overview

Conditional logic allows you to control how fields behave based on the values entered in other fields. You can use it to:

- **Show or hide** a field until another answer matches your rule
- **Show or hide** a layout element-headers, dividers, images, and rich text blocks-so whole sections appear and disappear cleanly
- Make a field **required only when** another answer matches your rule

This is useful for keeping forms focused. For example, you might show follow-up questions only when an incident severity is **Low**, hide a section's header and divider along with the questions they group, or make extra details required only when a particular checkbox is selected.

## How Conditions Work

Each condition is made up of three parts:

- **Source field** - the field whose value is being evaluated, such as **Severity of Incident**
- **Operator** - the rule applied to that value, such as **Equals**, **Is before**, or **Is after**
- **Comparison value** - the answer or value being compared against, such as **Low** or **08/04/2026 00:00**

When the condition is met, Astalty applies the behaviour you configured on the target field.

> **Source fields and target fields**
>
> You can add visibility conditions to regular form fields and to layout elements
> (headers, dividers, images, and rich text blocks) in the Form Builder. The
> **When field** list only shows field types Astalty can compare, such as dropdowns,
> radio buttons, multi-select fields, checkboxes, text fields, number fields, money
> fields, dates, and date/time fields.

## Show or Hide a Field

To show a field only when another field matches a condition:

1. Go to **Forms** > **Manage Forms** and open the form.
2. Open the **Form Builder**.
3. Click the field you want to show or hide.
4. In the field settings panel, go to **Visibility**.
5. Click **Add condition**.
6. Select the **When field**.
7. Select the **Operator**.
8. Enter or select the **Value**, if the operator needs one.
9. Click **Save**.

![The Form Builder for an unpublished Staff Injury Report, with the Visibility settings highlighted: When field Severity of Incident, Operator Equals and Value High. Arrows point to the Severity of Incident question and the highlighted Further information required field.](https://docs.astalty.com.au/assets/forms-conditional-visibility-example.png)

Fields with visibility conditions are hidden until at least one of their conditions is met. If a hidden field has been answered, its value is not submitted with the form.

## Show or Hide Layout Elements

Visibility conditions also work on layout elements-**headers**, **dividers**, **images**, and **rich text blocks**-not just question fields. This means a section's heading and divider can hide along with the questions they group, instead of leaving an empty heading behind.

Set it up the same way as any other field:

1. Open the **Form Builder** and click the header, divider, image, or rich text block.
2. In the settings panel, go to **Visibility**.
3. Click **Add condition**.
4. Select the **When field**, **Operator**, and **Value**.
5. Click **Save**.

Layout elements can only be **targets** of a condition-they don't collect an answer, so they can't be used as the **When field**, and they don't have a **Required** setting to control conditionally.

## Make a Field Required Conditionally

You can also make a field required only when another field matches a condition:

1. Open the field in the **Form Builder**.
2. Under **Required**, select **Required only when...**.
3. Click **Add condition**.
4. Select the **When field**, **Operator**, and **Value**.
5. Click **Save**.

If a field is set to **Always required**, it cannot also be conditionally required. Change the Required setting to **Required only when...** before adding required conditions.

## Supported Source Fields and Operators

The operators available depend on the type of source field selected:

| Source field type                        | Available operators                                                                                   | Value needed?                                                 |
| ---------------------------------------- | ----------------------------------------------------------------------------------------------------- | ------------------------------------------------------------- |
| Dropdown, radio buttons, multi-select    | **Equals**, **Does not equal**                                                                        | Select one of the field's options                             |
| Checkbox                                 | **Is checked**, **Is not checked**                                                                    | No                                                            |
| Single line text, multi line text, email | **Equals**, **Does not equal**, **Contains**, **Is empty**, **Is not empty**                          | Text value, except for empty/not empty operators              |
| Number, money                            | **Equals**, **Does not equal**, **Is greater than**, **Is less than**, **Is empty**, **Is not empty** | Number value, except for empty/not empty operators            |
| Date, date and time                      | **Equals**, **Is before**, **Is after**, **Is empty**, **Is not empty**                               | Date or date/time value, except for empty/not empty operators |

For example, a date or date/time source field offers these operators:

![A Visibility condition with the When field set to Date and Time of Incident and the Operator list open, showing Equals, Is before, Is after, Is empty and Is not empty.](https://docs.astalty.com.au/assets/forms-conditional-datetime-operators.png)

Some field types can be condition targets but cannot be used as the **When field** because Astalty cannot compare their answers in conditions. Examples include layout elements, file uploads, address fields, mobile phone fields, Participant/user/site select fields, and rating fields.

## Multiple Conditions

You can add more than one condition to the same field. Astalty treats multiple conditions as **or** rules, meaning the field is shown or required when any one of the saved conditions is met.

For visibility conditions, Astalty also checks whether the source field is visible. If a condition depends on a source field that is currently hidden, that condition is not met. Astalty prevents circular visibility rules, such as Field A depending on Field B while Field B also depends on Field A.

## Examples

### Show a follow-up field for a selected severity

A form includes a **Severity of Incident** dropdown with options **Low**, **Medium**, **High** and **Extreme**. You only want to ask a follow-up question when the person selects **Low**.

On the follow-up field, add a visibility condition:

- **When field:** Severity of Incident
- **Operator:** Equals
- **Value:** Low

The follow-up field stays hidden until **Low** is selected.

### Hide a whole section until it's relevant

A form has an **Anything else to report?** checkbox followed by a section made up of a **header**, a **divider**, and a few follow-up questions. You only want the whole section to appear when the checkbox is ticked.

Add the same visibility condition to the header, the divider, and each follow-up field:

- **When field:** Anything else to report?
- **Operator:** Is checked

The header, divider, and questions stay hidden together until the checkbox is ticked, so there's no empty heading left behind when the section isn't needed.

### Show a field after a specific date and time

A form includes a date/time field. You only want another field to appear when the date/time entered is after **08/04/2026 00:00**.

On the target field, add a visibility condition:

- **When field:** the date/time field
- **Operator:** Is after
- **Value:** 08/04/2026 00:00

![A Visibility condition with the When field set to Date and Time of Incident, Operator set to Is after and Value set to 08/04/2026 00:00, with Save and Cancel buttons.](https://docs.astalty.com.au/assets/forms-conditional-datetime-after-example.png)

You can use the same date/time field with **Equals**, **Is before**, **Is empty**, or **Is not empty** depending on the scenario.

See [Form Builder](https://docs.astalty.com.au/guide/forms/manage-forms/form-builder) for the other field and layout options.

> **Editing an answer on a submitted form**
>
> Changing an answer that controls a condition re-evaluates it on the submission too - see [Follow-Up Questions Update When You Edit an Answer](https://docs.astalty.com.au/guide/forms/manage-forms/submissions#follow-up-questions-update-when-you-edit-an-answer).