Add ACF Post Object field to Wordpress admin column

Question

I have a custom post type for books that has two ACF fields, book_title and book_author. I have a separate custom post type for passages from the book, which pulls in a book, as an ACF post object, into two fields in the passages custom post type with the same field names.

I would like to be able to display the book_title and book_author fields as columns in the passages custom post type list. I am currently able to pull in the title of the book, but thats only because I am grabbing the title of the post, not the actual book_title field from the post. Is there a way to grab fields from a post object like this and set them as columns?

Here is my current code from my passages custom post type file:

function add_acf_columns($columns)
{
    return array_merge($columns, array(
        'book_title' => __('Book Title') ,
        'book_author' => __('Book Author')
    ));
}
add_filter('manage_passages_posts_columns', 'add_acf_columns');


function passages_custom_column($column, $post_id)
{
    switch ($column)
    {
        case 'book_title':
            echo get_the_title(get_field('book_title', $post_id));
        break;
        case 'book_author':
            echo get_post_meta($post_id, 'book_author', true);
        break;
    }
}
add_action('manage_passages_posts_custom_column', 'passages_custom_column', 10, 2);

Answer 1

I'm a tad confused on your actual set up, but the general idea should apply here. When using the ACF "Relational > Post Object" field, it stores the actual relative WP_Post object. This allows you to reference anything you want from it without having to invoke anything special.

Just doing the following:

$object = get_field( 'name_of_field', $post_id );

Will give you access to whatever data you want from that post/custom post type:

$title = $object->post_title;
$author_id = $object->post_author;

So, like I mentioned, I'm a bit confused on your actual field names and where the actual object is stored, but I think the same post object is stored in both the book_title and book_author fields? Either way, you just need to get the WP_Post object with get_field, and then you'll have access to everything related to it. Then you can ouput the title, and use something like get_the_author_meta() to get the author's display/first/last name, etc.

add_action('manage_passages_posts_custom_column', 'passages_custom_column', 10, 2);
function passages_custom_column($column, $post_id) {
    switch( $column ){
        case 'book_title':
            $book_object = get_field( 'book_title', $post_id );
            echo ($book_object) ? $book_object->post_title : '';
            break;
        case 'book_author':
            $book_object = get_field( 'book_author', $post_id );
            if( $book_object ){
                echo get_the_author_meta( 'display_name', $book_object->post_author );
            }
            break;
    }
}

Answer 2

I solved this by modifying Xhynk's answer.

After you grab the ID of the Book post object in the Passages post book field, you can use ACF's get_field() to grab the title and author values from the Book post itself, and then pass those values into the columns.

// add columns to passages list
add_filter('manage_passages_posts_columns', 'add_acf_columns');
function add_acf_columns($columns)
{
    return array_merge($columns, array(
        'book_title' => __('Book Title') ,
        'book_author' => __('Book Author')
    ));
}

// add title and author to passages list columns
add_action('manage_passages_posts_custom_column', 'passages_custom_column', 10, 2);
function passages_custom_column($column, $post_id) {
    switch( $column ){
        case 'book_title':
            $book_object = get_field( 'book', $post_id );
            $book_title = get_field('title', $book_object->ID);
            echo ($book_title) ? $book_title : '';
            break;
        case 'book_author':
            $book_object = get_field( 'book', $post_id );
            $book_author = get_field('author', $book_object->ID);
            echo ($book_author) ? $book_author : '';
            break;
    }
}