## Summary Add a "Load MDXEditor" checkbox to the field widget settings for plain text fields, so site builders can enable the editor through Drupal's configuration UI without writing any code. ## Problem The `ai` module ships with MDXEditor support for textarea form elements. Currently the only way to activate it is by adding the `data-mdxeditor` HTML attribute programmatically in PHP: ```php $form['body'] = [ '#type' => 'textarea', '#attributes' => ['data-mdxeditor' => 'my-editor-id'], ]; ``` This means site builders cannot enable MDXEditor through the UI — a developer is always required. There is no way to opt a content field into MDXEditor from `/admin/structure/types/manage/{type}/form-display`. ## Proposed solution Add a "Load MDXEditor" toggle to the widget settings form for plain text fields (`string_long`, `text_long`, `text_with_summary`). When toggled on, the editor is automatically attached to the widget's textarea during content editing. The implementation follows the pattern already used in the `field_widget_actions` submodule: 1. `hook_field_widget_third_party_settings_form()` — render the checkbox on the widget settings form 2. `hook_field_widget_settings_summary()` — show "MDXEditor: enabled" in the widget summary column 3. `hook_field_widget_single_element_form_alter()` — inject `data-mdxeditor` (and `drupalSettings` if needed) into the textarea element when the setting is active ## Workaround Add the `data-mdxeditor` attribute manually via a custom module using `hook_field_widget_single_element_form_alter()`. ## Affected modules / components `ai` (core module) — MDXEditor integration lives in `src/Hook/FormElement.php` and `docs/developers/mdxeditor.md`. The feature could also live in a new submodule.