This is just an example and you have to customize it for your needs:
First step: Adding Meta container hook to backend (for example here for products post type):
add_action( 'add_meta_boxes', 'extra_info_add_meta_boxes' );
if ( ! function_exists( 'extra_info_add_meta_boxes' ) )
{
function extra_info_add_meta_boxes()
{
global $post;
add_meta_box( 'extra_info_data', __('Extra Info','your_text_domain'), 'extra_info_data_content', 'product', 'side', 'core' );
}
}
(replace 'product'
by your post type and this meta box could be like here on 'side'
or by 'normal' to get it on main column)
Second step: Adding information in this metabox (fields, data, whatever…)
function extra_info_data_content()
{
global $post;
// Here you show your data <=====
}
References:
Third step (optional): Save the data of the custom meta post (needed if you have some fields).
add_action( 'save_post', 'extra_info_save_woocommerce_other_fields', 10, 1 );
if ( ! function_exists( 'extra_info_save_woocommerce_other_fields' ) )
{
function extra_info_save_woocommerce_other_fields( $post_id )
{
// Check if our nonce is set.
if ( ! isset( $_POST[ 'extra_info_other_meta_field_nonce' ] ) )
{
return $post_id;
}
$nonce = $_REQUEST[ 'extra_info__other_meta_field_nonce' ];
//Verify that the nonce is valid.
if ( ! wp_verify_nonce( $nonce ) )
{
return $post_id;
}
// If this is an autosave, our form has not been submitted, so we don't want to do anything.
if ( defined( 'DOING_AUTOSAVE' ) && DOING_AUTOSAVE )
{
return $post_id;
}
// Check the user's permissions.
if ( 'page' == $_POST[ 'post_type' ] )
{
if ( ! current_user_can( 'edit_page', $post_id ) )
{
return $post_id;
}
}
else
{
if ( ! current_user_can( 'edit_post', $post_id ) )
{
return $post_id;
}
}
/* --- !!! OK, its safe for us to save the data now. !!! --- */
// Sanitize user input and Update the meta field in the database.
}
}