Register Custom Beaver Builder Module and Custom Field

class-post-category-list-module.php

<?php
/**
 * Posts Category List class and registration call.
 *
 * @package WDS_BB_Custom_Field
 * @since 1.0
 */

/**
 * Post Category List Module.
 *
 * @author Justin Foell <justin.foell@webdevstudios.com>
 * @since  1.0
 */
class Post_Category_List_Module extends FLBuilderModule {

	/**
	 * Default post count limit.
	 *
	 * @since 1.0
	 */
	const POST_COUNT_DEFAULT = 5;

	/**
	 * Module constructor.
	 *
	 * @see https://kb.wpbeaverbuilder.com/article/597-cmdg-02-add-a-module-to-your-plugin
	 * @author Justin Foell <justin.foell@webdevstudios.com>
	 * @since  1.0
	 */
	public function __construct() {
		parent::__construct(
			array(
				'name'        => esc_html__( 'Post Category List', 'wds-bb-custom-field' ),
				'description' => esc_html__( 'A post category list module.', 'wds-bb-custom-field' ),
				'group'       => esc_html__( 'WDS Modules', 'wds-bb-custom-field' ),
				'category'    => esc_html__( 'Posts', 'wds-bb-custom-field' ),
				'dir'         => plugin_dir_path( __FILE__ ),
				'url'         => plugins_url( dirname( __FILE__ ) ),
			)
		);
	}

	/**
	 * Set up a WP_Query based on our module's settings.
	 *
	 * @return WP_Query
	 * @author Justin Foell <justin.foell@webdevstudios.com>
	 * @since  1.0
	 */
	public function category_posts_query() {
		return new WP_Query( array(
			'posts_per_page' => $this->settings->post_count,
			'tax_query'      => array(
				array(
					'taxonomy' => 'category',
					'field'    => 'id',
					'terms'    => $this->settings->post_categories,
				),
			),
		) );
	}
}

/**
 * Register the module and its form settings.
 *
 * @see https://kb.wpbeaverbuilder.com/article/598-cmdg-03-define-module-settings
 * @since 1.0
 */
FLBuilder::register_module(
	'Post_Category_List_Module', array(
		'general' => array(
			'title'    => esc_html__( 'General', 'wds-bb-custom-field' ),
			'sections' => array(
				'general' => array(
					'fields' => array(
						'list_title'      => array(
							'type'        => 'text',
							'label'       => esc_html__( 'List Title', 'wds-bb-custom-field' ),
							'default'     => '',
							'placeholder' => esc_html__( 'Enter a title or leave blank to omit', 'wds-bb-custom-field' ),
						),
						'post_count'      => array(
							'type'    => 'unit',
							'label'   => esc_html__( 'Number of Posts', 'wds-bb-custom-field' ),
							'default' => Post_Category_List_Module::POST_COUNT_DEFAULT,
						),
						'post_categories' => array(
							'type'  => 'wds-bb-post-categories',
							'label' => esc_html__( 'Categories to Include', 'wds-bb-custom-field' ),
						),
					),
				),
			),
		),
	)
);

class-wds-bb-custom-field-plugin.php

<?php
/**
 * The main class for our plugin.
 *
 * @package WDS_BB_Custom_Field
 * @since 1.0
 */

/**
 * Plugin class.
 *
 * @author Justin Foell <justin.foell@webdevstudios.com>
 * @since  1.0
 */
class WDS_BB_Custom_Field_Plugin {

	/**
	 * Hook it up!
	 *
	 * @author Justin Foell <justin.foell@webdevstudios.com>
	 * @since  1.0
	 */
	public function register_hooks() {
		// Load custom modules.
		add_action( 'init', array( $this, 'load_modules' ) );

		// Register custom fields.
		add_filter( 'fl_builder_custom_fields', array( $this, 'register_fields' ) );
	}

	/**
	 * Load a custom module.
	 *
	 * @author Justin Foell <justin.foell@webdevstudios.com>
	 * @since  1.0
	 */
	public function load_modules() {
		require_once WDS_BB_CUSTOM_FIELD_DIR . 'include/modules/post-category-list/class-post-category-list-module.php';
	}

	/**
	 * Register custom field(s) for our module.
	 *
	 * @param array $fields Beaver Builder fields - index is the field name, value is the file path.
	 * @return array $fields Beaver Builder fields with additional custom fields.
	 * @author Justin Foell <justin.foell@webdevstudios.com>
	 * @since  1.0
	 */
	public function register_fields( $fields ) {
		$fields['wds-bb-post-categories'] = WDS_BB_CUSTOM_FIELD_DIR . 'include/fields/post-categories.php';
		return $fields;
	}

}

post-categories.php

<?php
/**
 * Custom field to select Post Categories.
 *
 * @see https://kb.wpbeaverbuilder.com/article/620-cmdg-14-create-custom-fields
 * @since 1.0
 * @package WDS_BB_Custom_Field
 */

foreach ( get_categories() as $category ) :
?>
	<div>
		<label>
			<#
			// debugger;
			var checked = '';
			if ( 'object' === typeof data.value && jQuery.inArray( '<?php echo esc_attr( $category->term_id ); ?>', data.value ) != -1 ) {
				checked = ' checked="checked"';
			}
			#>
			<input type="checkbox" name="{{data.name}}[]" value="<?php echo esc_attr( $category->term_id ); ?>"{{{checked}}}/>
			<?php echo esc_html( $category->name ); ?>
		</label>
	</div>
<?php
endforeach;