How to force one column layout on custom post type edit page?

Question

I've created a plugin using custom post types and I need to force the default two column post page to a single column. At the same time, the Publish metabox must move to the bottom. I need to do this via the functions some how.

I have some solutions from WPSE, but the only solution I've found actually hides the "Publish" metabox. I can't seem to figure out why.

Any ideas of how to do this?

Answer 1

There is a filter called get_user_option_meta-box-order_{$page} where $page is the name of the post type. Just make sure that submitdiv is the last value in the array:

add_filter( 'get_user_option_meta-box-order_post', 'wpse25793_one_column_for_all' );
function wpse25793_one_column_for_all( $order )
{
    return array(
        'normal'   => join( ",", array(
            'postexcerpt',
            'formatdiv',
            'trackbacksdiv',
            'tagsdiv-post_tag',
            'categorydiv',
            'postimagediv',
            'postcustom',
            'commentstatusdiv',
            'slugdiv',
            'authordiv',
            'submitdiv',
        ) ),
        'side'     => '',
        'advanced' => '',
    );
}

Answer 2

One approach is to remove the original metabox, and then to re-add that metabox, with updated parameters. For example, this will move the "Featured Image" meta box from the side column to the main column, for a custom post type with a slug cpt-slug:

Edit

The parameter for the Publish meta box is submitdiv, and the correct callback is post_submit_meta_box(); I've updated the code below to reflect these correct parameters. I've also changed the add_meta_box() $context parameter from 'high' to 'low', so that the Publish meta box will be added at the bottom:

<?php
function wpse25793_move_post_metaboxes( $post ) {
    global $wp_meta_boxes;

    remove_meta_box( 'submitdiv', 'cpt-slug', 'side' );
    add_meta_box( 'submitdiv', __( 'Publish' ), 'post_submit_meta_box', 'cpt-slug', 'normal', 'low' );
}
add_action( 'add_meta_boxes_cpt-slug', 'wpse25793_move_post_metaboxes' );
?>

The approach should be the same for the "Publish" meta box. You just need to remove/add the publish meta box instead of the featured image meta box.

Answer 3

To answer the second part of the question - How to force one column, you can do it with get_user_option_screen_layout_{Post_type} filter. Let's say for product post-type:

$func = function( $result, $option, $user ){
    return '1';
};
add_filter( "get_user_option_screen_layout_product", $func, 10, 3 );