Hi,
Problem/Motivation
When mapping a menu (e.g. main or footer) to a Links-type prop in a UI Patterns pattern, Drupal allows the use of special tokens in the menu link URLs:
-
<front> : works as expected
<nolink> : works as expected<button>: the link is completely removed from the output
This behavior is problematic, as Drupal's admin UI explicitly allows adding button-type links to menus. However, the UI Patterns module does not currently support this case properly, which prevents the button from being rendered.
Steps to reproduce
- Drupal core version: 10.4
- UI Patterns module version: 2.x
- Menu items are MenuLinkContent entities.
Links are mapped to a prop of type Links, using a schema defined by LinksPropType, which expects the following structure:
[
'type' => 'object',
'properties' => [
'title' => ['type' => 'string'],
'url' => ['$ref' => 'ui-patterns://url'],
'attributes' => ['$ref' => 'ui-patterns://attributes'],
'link_attributes' => ['$ref' => 'ui-patterns://attributes'],
'below' => [
'type' => 'array',
'items' => [
'type' => 'object',
],
],
],
]
However, when a link uses the <button> token in the Link field, the preprocessing handled by the normalize() method in UrlPropType returns an empty string ('') for the URL.
As a result, the schema validation for LinksPropType either rejects or silently ignores the item, because it no longer matches the expected format for a valid link.
This use case can be essential, particularly for accessibility reasons, such as:
- A parent menu link used only to trigger expand/collapse behavior
- A menu item that opens a consent modal
- A purely interactive navigation element that doesn’t need an actual URL
Proposed resolution
Menu items with a <button> URL should be included in the Links prop, with an identifiable format for example, a type: 'button' field or a boolean is_button allowing the front-end integrator to distinguish and render the element appropriately (e.g., using a <button> instead of an <a> tag).
Marc