book_form_update

book_form_update($form, FormStateInterface $form_state)

Renders a new parent page select element when the book selection changes.

This function is called via Ajax when the selected book is changed on a node or book outline form.

Return value

The rendered parent page select element.

File

core/modules/book/book.module, line 207

Allows users to create and organize related content in an outline.

Code

function book_form_update($form, FormStateInterface $form_state) {
  return $form['book']['pid'];
}