Dump the constant MY_CUSTOM_POST_TYPE
use the $post->post_type
instead.
/**
* Register the meta box
*/
add_action('add_meta_boxes', 'page_templates_dropdown_metabox');
function page_templates_dropdown_metabox(){
global $post;
add_meta_box(
$post->post_type.'-page-template',
__('Template', 'my_template'),
'render_page_template_dropdown_metabox',
$post->post_type,
'side', #I prefer placement under the post actions meta box
'low'
);
}
/**
* Render your metabox - This code is similar to what is rendered on the page post type
* @return void
*/
function render_page_template_dropdown_metabox(){
global $post;
$template = get_post_meta($post->ID, '_wp_page_template', true);
echo "
<label class="screen-reader-text" for="page_template">Page Template</label>
<select name="_wp_page_template" id='page_template'>
<option value="default">Default Template</option>";
page_template_dropdown($template);
echo "</select>";
}
/**
* Save the page template
* @return void
*/
function save_page_template($post_id){
# Skip the auto saves
if ( defined( 'DOING_AUTOSAVE' ) && DOING_AUTOSAVE )
return;
elseif ( defined( 'DOING_AJAX' ) && DOING_AJAX )
return;
elseif ( defined( 'DOING_CRON' ) && DOING_CRON )
return;
update_post_meta($post_id, '_wp_page_template', esc_attr($_POST['_wp_page_template']));
}
add_action('save_post', 'save_page_template');
/**
* Set the page template
* @param string $template The determined template from the WordPress brain
* @return string $template Full path to predefined or custom page template
*/
function set_page_template($template){
global $post;
$custom_template = get_post_meta($post->ID, '_wp_page_template', true);
if($custom_template)
#since our dropdown only gives the basename, use the locate_template() function to easily find the full path
return locate_template($custom_template);
return $template;
}
add_filter('single_template', 'set_page_template');
Code not tested
Code will show the dropdown for all post types.