How to get source of custom meta image?

Question

I'm working on a CPT (custom post type) page template and would like to get the source of custom meta image.

For post_thumbnail's this is rather easy using wp_get_attachment_image_src(), but if I var_dump( $post->ID ) I don't see a value for my custom meta attachment image source.

So how can I get the ID of my custom-meta-image to get it's source? Thanks :)

UPDATE This is what I got going.

<?php $portfolio_image_one = get_post_meta( $post->ID, '_cmb_portfolio_image_one', true ); ?>
<?php $portfolio_image_two = get_post_meta( $post->ID, '_cmb_portfolio_image_two', true ); ?>
<?php $portfolio_image_three = get_post_meta( $post->ID, '_cmb_portfolio_image_three', true ); ?>

<?php if ( has_post_thumbnail() ) {
$large_image_url = wp_get_attachment_image_src( get_post_thumbnail_id(), 'large'); ?>
<a class="featured-image" href="<?php echo $large_image_url[0] ?>" title="' . <?php the_title_attribute('echo=0') ?> . '">
<?php the_post_thumbnail('medium', array('class' => 'img-polaroid')); ?>
</a>
<?php } ?>

Basically, I would like to get the ID for my post_meta images in a similar way to the thumbnail approach.

Answer 1

Custom Meta Image? What's that?

Do you mean that,

• you are inserting an image into a custom field (post meta field) within your meta box?

• you are inserting an image as a post attachment or thumbnail?

These are two very different things one of which is dealing with,

add_post_meta

the other,

wp_insert_attachment

The latter of which inserts attachments into your media library which is associated with your wp_posts database table.

Post meta on the other hand (i.e. add_post_meta etc) is associated with your wp_postmeta' database table.

Attachments are actually classified as a post_type just line post or page or your custom_post_type for instance.

Attachments, as a post type, may or may not also then be associated with a Post's ID, stored as an integer in the post_parent column in your wp_posts database. If set to 0, this means that the attachment has no parent and is not associated with any particular post.

Theory aside...

You may very well be trying to access an attachment that simply doesn't exist in the first place.

$attachment_id = 20; //example ID of the attachment you want to retrieve
$attachment = wp_get_attachment_image_src( $attachment_id );
echo $attachment[0];

The particular code above is useful for retrieving an attachment which is not associated with any particular post.

$post_id = 100; //example post ID
$attachment = wp_get_attachment_thumb_url( $post_id );
echo $attachment; //returns the URL of the image attached to the post

Where as retrieving an value, regardless of what that value is, when dealing with post meta (as you referred to as custom meta image) requires the use of,

get_post_meta

In use,

$post_id = get_the_ID();
$meta = get_post_meta($post_id, 'your_meta_key');
echo $meta;

API References

• WordPress API: add_post_meta
• WordPress API: wp_get_attachment_image_src
• WordPress API: wp_get_attachment_thumb_url
• WordPress API: wp_insert_attachment
• WordPress API: get_post_meta

UPDATE

Based on your code,

$portfolio_image_one = get_post_meta( $post->ID, '_cmb_portfolio_image_one', true );

The post_meta value is held within your variable,

$portfolio_image_one

What you need to do is,

echo $portfolio_image_one;

Otherwise nothing is going to happen.

If there is a value stored for the meta_key i.e. _cmb_portfolio_image_one then by echoing the result of the variable, you shall be presented with your meta_value whatever that value is, such as http://domain.com/my_image.jpg for example.

If $post->ID is being used outside of the loop you will run into trouble, hence refer to my previous example, but with your code,

$post_id = get_the_ID();
$portfolio_image_one = get_post_meta($post_id, '_cmb_portfolio_image_one', true);
echo $portfolio_image_one;