link featured image to external link

Question

I made custom post type "Collections" and I populate every post through featured image. Now I need to link every featured image to appropriate external link. So far I managed to add meta box to media uploader with this piece of code in functions.php:

    function be_attachment_field_credit( $form_fields, $post ) {


    $form_fields['be-url'] = array(
        'label' => 'URL',
        'input' => 'text',
        'value' => get_post_meta( $post->ID, 'be_url', true ),
        'helps' => 'Add URL',
    );

    return $form_fields;
}

add_filter( 'attachment_fields_to_edit', 'be_attachment_field_credit', 10, 2 );



function be_attachment_field_credit_save( $post, $attachment ) {


    if( isset( $attachment['be-url'] ) )
update_post_meta( $post['ID'], 'be_url', esc_url( $attachment['be-url'] ) );

    return $post;
}

add_filter( 'attachment_fields_to_save', 'be_attachment_field_credit_save', 10, 2 );

And then in my single.php I add

echo get_post_meta(get_post_thumbnail_id(), 'be_url', true);

Now, when I click on featured image in admin panel in order to populate the meta box with url (for example http://www.google.com), the metabox saves the link, but when I go to my page where my featured image is, the featured image is not linked at all. How do i make my featured image go to external link? Thanx.

Answer 1

In WordPress attachments are treated as posts, with their own titles, excerpts and metavalues. So if a post has an attachment there are two sets of metavalues, one for the post itself and one for the attachment.

You are using update_post_meta( $post['ID'] ... to store the url. So it is stored as a metavalue of the post.

You are retrieving with get_post_meta(get_post_thumbnail_id() ..., so you are looking for a metavalue of the attachment. To retrieve it you must not use get_post_thumbnail_id() but $post['ID'], because that's where you stored that url.