Conditional Logic

Conditional logic shows or hides a field depending on what the visitor has entered in other fields. A rule such as "show Order number when Reason is Support" is applied live in the browser as the visitor types, and enforced again on the server when the form is sent, so hiding a field really does remove it.

Add a rule

1. Open the Logic tab. You need at least two input fields on the Build tab to make a rule.
2. In + Add condition…, pick the field the rule will show or hide. This is the target field.
3. The rule reads as a sentence. Choose Show or Hide, then all or any of the rules, and set the rule itself: which field to look at, an operator, and a value.
4. Click Add rule for more rules, or the remove button to delete one.
5. Click Save.

Each target field gets a card. A field can have more than one card (one group of rules each). The target is hidden when any of its groups says so, so groups combine as "and". The fields offered as targets and as rule sources are the input fields. Layout fields, the honeypot and challenge fields are left out, since they have no answer a rule could test. A field cannot test itself.

For a choice field (a Dropdown, Radio Buttons, Checkboxes or Recipients field) the value box becomes a list of its options, and for a single Checkbox, Toggle or Switch the value is Checked. The stored value is the option's key, not its label.

A rule with no field, or with nothing to compare against, is flagged Incomplete. The Logic tab shows a count, and the form cannot be saved until each rule has a value or is removed. This stops a half-made rule from quietly hiding a field for the wrong people. To test for a blank answer, use is empty.

Operators

A field holding several values (Checkboxes, or a Dropdown with several selections) is compared as its values joined by commas, so contains is the operator to ask "is this one ticked?".

What hidden means

In the browser, a hidden field is not shown and its inputs are disabled, so the browser skips them when it checks the form and they are not sent. On the server, a field the rules hide for the submitted answers is handled so that:

• Its Required is dropped, so an empty hidden field never blocks the form.
• Whatever was posted for it is thrown away before any action runs. A visitor who typed something, then changed their answer so the field hid, does not leave a stale value in the entry, the email or the webhook.
• It counts as blank in calculations. See Calculations.

The server works the rules out from the posted answers, not from anything the browser claims, so a tampered form gains nothing.

The YAML

Rules live on the target field under conditions, a list of groups. This form was tested as written. Tell us more is required, but only when Reason is Other, and Order number shows for Support or Sales:

fields:
  reason:
    type: select
    label: Reason
    options:
      sales: Sales
      support: Support
      other: Other
    validate:
      required: true
  other_reason:
    type: text
    label: Tell us more
    validate:
      required: true
    conditions:
      - action: show
        logic: all
        rules:
          - field: reason
            operator: is
            value: other
  order_number:
    type: text
    label: Order number
    conditions:
      - action: show
        logic: any
        rules:
          - field: reason
            operator: is
            value: support
          - field: reason
            operator: is
            value: sales

A rule's field can reach into a composite field with a dot, such as full_name.first for the first name of a Name field. The Logic tab does not offer that, but it works when written by hand.

Related

• Field reference
• Calculations
• Actions and notifications