Add custom admin column callback to post type

custom-column-callback.php

<?php
/**
 * Functions may be used as a custom post type column callback
 */
 
/**
 * If the function name does not contain 'jet_engine_custom_cb' prefix, 
 * the callback takes only two arguments: column name and post ID
 * You may use such callbacks if you do not need to specify any arguments
 * Example: show post author in a column
 */

function show_post_author_ac( $column, $post_id ) {
	
	$post = get_post( $post_id );

	$author_id = $post->post_author;
	$author    = get_user_by( 'ID', $author_id );
	
	if ( ! $author ) {
		return;
	}
	
	return $author->user_nicename;
}

/**
 * If the function name contains 'jet_engine_custom_cb' prefix, callback may take any number of arguments.
 * When using that callback in CPT, specify its arguments as follows:
 * jet_engine_custom_cb_modified_date::arg1::arg2::arg3 (any number of arguments, separated by '::')
 * Example: show post modified date with the ability to specify the format
 */

function jet_engine_custom_cb_modified_date( $post_id, $format = 'd.m.Y' ) {

	$post = get_post( $post_id );
	
	if ( ! $post ) {
		return;
	}
	
	$modified = $post->post_modified;
	$modified = strtotime( $modified );
	$modified = wp_date( $format, $modified );
	
	return $modified;
	
}


/**
 * For convenience, callbacks may be added to the list of predefined callbacks
 * using the filter 'jet-engine/post-type/predifined-columns-cb-for-js', which filters the array of callbacks
 */
add_filter( 'jet-engine/post-type/predifined-columns-cb-for-js', function( $column_callbacks ) {
	
	$column_callbacks[ 'jet_engine_custom_cb_modified_date' ] = array(
					'description' => __( 'Get post modified date', 'jet-engine' ),
					'args'        => array(
						'format' => array(
							'label'       => __( 'Format', 'jet-engine' ),
							'description' => __( 'Date format', 'jet-engine' ),
							'value'       => 'd.m.Y',
						),
					),
				);
	
	$column_callbacks[ 'show_post_author_ac' ] = array(
					'description' => __( 'Show post author', 'jet-engine' ),
				);
	
	return $column_callbacks;
} );