Applying if (get_post_meta) to new shortcode

Question

It's my first time here so here goes :)

I've created a custom image field which allows me to upload new images, or have images added via a form from the frontend. I want these to display.

I'm creating a shortcode like so:

    function display_ad() {
    global $post;
    return do_shortcode( '<a href="' . get_permalink($id) . '">' . '<img src="' . get_post_meta( $post->ID , "wpcf-display-ad" , true ) . '"/>' . '</a>' );
    }
    add_shortcode('display-ad', 'display_ad');

This works fine - images are displayed and link to their respective post, but for posts that don't contain a display image, the src tag still returns (and any css, for example a border, too).

I'm struggling to figure out how to apply the if statement to the above code, i.e:

    if ( get_post_meta( $post->ID , "wpcf-display-ad" , true ) ) :

... so that if an image doesn't exist then nothing is returned.

---

Hi Abdussamad

Thanks for your suggestions. I've just spent the last hour trying to wrap my head around them and them to work, but no joy. I must warn you I'm very much at the early stages of PHP :)

Here's what I've done based on your comments:

function display_ad() {
global $post;
$content = get_permalink($id);
$ad_image = get_post_meta( $post->ID , "wpcf-display-ad" , true );
if( empty( get_post_meta( $post->ID, 'wpcf-display-ad', true ) ) ) {
return $content;
} else {
return $content . $ad_image;
}
}
add_shortcode('display-ad', 'display_ad');

However, this just returns a white screen.

I have two posts up at the moment on my development site (one with a display ad, the other not), and if I remove the if statement bit, and just return $content; then the posts and their permalinks display. If I just return $ad_image; again the posts display together, one showing the path to the image, the other blank (but present in Chrome's Developer Tools panel).

However, with the if statement I get the white screen. Evidently I'm doing something wrong. Thanks for your help.

Gavin.

Answer 1

First up the display_ad function should have a parameter $content that contains the post's content upto the point where the shortcode is placed. So you concatenate that $content with your advertisement image before returning it.

Second what's wrong with :

if( empty( get_post_meta( $post->ID, 'wpcf-display-ad', true ) ) ) {
   return $content;
 } else {
    return $content . $ad_image;
 }