Add Field Hook for Customizing Field-Level Duplication Behavior

[jessrynkar]

Background

Currently, when duplicating a single field (not an entire document), field values are copied as-is, with no way to easily customize or reset specific values before/after duplication. This limitation requires users to manually clean up fields, which can be tedious and lead to errors.

We support this functionality when duplicating an entire document — which allows developers to do useful things like define how unique fields should behave or reset fields. This is achieved via the beforeDuplicate hook, which can be applied at the collection or field level — but it only triggers during document duplication.

We should support similar functionality that triggers during field-level duplication. For example, if the user has a complex blocks field where each block contains a readyToPublish checkbox. When a block is duplicated, it is not ideal for that checkbox to remain checked. Developers should be able to reset the duplicated block to an unpublished state.

Proposed Feature

Introduce a new field-level hook — beforeFieldDuplicate (or a similar) — that is called only when a field, or one of its parent fields, is duplicated.

This hook would give developers full control to transform or reset field values during duplication. Example usage:

{
  name: 'sponsors',
  type: 'array',
  fields: [
    // other top-level fields
    {
      name: 'settings',
      type: 'group',
      fields: [
        {
          name: 'readyToPublish',
          type: 'checkbox',
          defaultValue: false,
          hooks: {
            beforeFieldDuplicate: [
              ({ value }) => {
                return false; // Reset checkbox to false on duplication
              },
            ],
          },
        },
      ],
    },
  ],
}

Benefits

• Mirrors existing functionality provided for document-level duplication.
• Enables fine-grained control at the field level — especially valuable for nested or repeatable content structures.
• Improves UX by preventing unintended value carryover in duplicated items.

Considerations

• This hook should only trigger during field-level duplication — not during full document duplication.
• When a field being duplicated contains nested fields, the beforeFieldDuplicate hook on those nested fields should also be triggered.