Demo of Fieldmanager_Datasource_CAP

demo-datasource-cap.php

<?php

require_once( __DIR__ . '/inc/class-fieldmanager-datasource-cap.php' );
add_action( 'fm_post_post', function() {
	$fm = new \Fieldmanager_Group( [
		'name' => 'byline',
		'limit' => 0,
		'label' => __( 'Author', 'cap-sandbox' ),
		'sortable' => true,
		'add_more_label' => __( 'Add a coauthor', 'cap-sandbox' ),
		'children' => [
			'author' => new \Fieldmanager_Autocomplete( [
				'label' => __( 'Author Name', 'cap-sandbox' ),
				'datasource' => new \Fieldmanager_Datasource_CAP,
			] ),
			'type' => new \Fieldmanager_TextField( __( 'Author Type', 'cap-sandbox' ) ),
		],
	] );
	$fm->add_meta_box( 'Authors', 'post' );
} );

/**
 * Remove CAP meta box for post types where we replaced it.
 */
add_action( 'add_meta_boxes', function() {
	global $coauthors_plus;
	if ( $coauthors_plus ) {
		remove_meta_box( $coauthors_plus->coauthors_meta_box_name, 'post', apply_filters( 'coauthors_meta_box_context', 'normal' ) );
	}
}, 20 );