Getting metabox value within a shortcode?

Question

Is it possible to get page's metabox value within shortcode that is executed on that page?

Scenario:

• I have a sidebar metabox for every page.
• I have some kind of custom gallery shortcode.

My gallery shortcode outputs 600x200 images (I'm using timthumb here).

BUT I want it to display 900x300 if there's no sidebar.

Normally I'd use:

$sidebar = get_post_meta($post->ID, 'metabox_sidebar', true);
   if($sidebar == "true") { do something }
   else { do something else }

But get_post_meta returns nothing within the shortcode body.

Answer 1

$post is outside the scope of your shortcode function, you have to globalize it first:

global $post;
$sidebar = get_post_meta($post->ID, 'metabox_sidebar', true);