Field Manual Override

Field Manual Override allows content editors to manually edit fields
managed by external data sources while protecting their changes from
being overwritten during imports or synchronization.

Features

Field Manual Override provides a simple way to manage fields that are
automatically populated by external systems while allowing content
editors to take control of individual field values when needed.

• Field-level manual overrides: Enable manual editing
  for individual fields without affecting other fields on the same entity.
• Automatic field locking: Fields remain disabled on
  entity edit forms until the editor enables the "Manual override" checkbox.
• Simple editorial experience: Editors can enable or
  disable manual overrides directly from the entity edit form, with
  checkboxes displayed alongside field labels.
• Configurable per field: Administrators can choose
  which fields support manual overrides through Drupal's field
  configuration interface.
• No additional fields required: Override settings
  are stored independently, without adding extra fields to content types.
• Translation support: Override states can be managed
  independently for different entity translations.
• Feeds integration: Protects manually overridden
  fields from being overwritten during imports performed by Feeds.
• Migrate integration: Preserves manually overridden
  field values when updating existing entities through Drupal's Migrate API.
• Developer-friendly API: Provides a reusable service
  for custom integrations to check whether a field has been manually overridden.
• Gin compatibility: Includes an interface designed
  to work with the Gin administration theme.

Common use cases include:

• Content synchronization: Preserve editorial changes
  to content regularly updated from external APIs.
• Location directories: Customize individual location
  descriptions, addresses, or contact information while keeping other
  data synchronized.
• Event management: Override specific event details
  imported from external event management platforms.
• Product catalogs: Maintain customized product
  descriptions while synchronizing other product information.
• Recurring migrations: Prevent subsequent migration
  runs from overwriting manually updated content.
• Hybrid content management: Combine externally
  managed information with locally maintained editorial content.

Post-Installation

After installing and enabling Field Manual Override, administrators
can configure which fields support manual overrides.

1. Navigate to Structure > Content types > Manage fields
   for the desired content type.
2. Edit the configuration of a field that should support manual overrides.
3. Enable the Allow manual override option and save
   the field configuration.
4. Navigate to an entity edit form containing the configured field.
5. Use the Manual override checkbox to control whether
   the field can be edited manually.

How manual overrides work:

• Manual override disabled (default): The field is
  disabled on the editing form and its value can be updated by supported
  external integrations.
• Manual override enabled: The field becomes editable,
  and supported integrations preserve its existing value during subsequent
  imports or synchronization.
• Manual override disabled again: The field returns
  to being managed by the external data source and can be updated during
  the next synchronization.

To enable automatic protection during imports, activate the appropriate
integration submodule:

• field_manual_override_feeds for Feeds imports.
• field_manual_override_migrate for Drupal Migrate API imports.

The core module can also be used independently with custom integrations
through its service API.

Important: Manual override is an editorial synchronization
feature, not a field-level security or permissions system. Programmatic
updates must respect override states through a supported integration or
the module's API.

Supporting this Module

Contributions from the Drupal community are welcome!

Technical Considerations

Developers can integrate manual override functionality into custom
synchronization workflows using the module's service API:

$manager = \Drupal::service('field_manual_override.manager');

if (!$manager->isOverridden($entity, 'field_description')) {
  $entity->set('field_description', $incoming_value);
}

This allows custom integrations to respect manual overrides without
requiring changes to the entity's field structure.

• Override states are stored separately from entity field values.
• Override configuration is managed at the field level.
• Override states are maintained for individual entities and translations.
• The core module does not globally prevent programmatic field updates.
• Feeds and Migrate integrations protect supported existing entities
  during import updates.
• Import processes may still execute their normal processing logic
  even when a field's existing value is preserved.
• Custom integrations should use the provided API to respect manual
  override states.

Field Manual Override is designed to provide a flexible, extensible
approach to managing content that combines automated synchronization
with manual editorial control.