Fallback image URL if no featured image exists via a shortcode function

Question

What I'm trying to do is add a fallback image to this shortcode function that grabs the featured image to account for the possibility that a post has no featured image. (This function creates a shortcode because I need to use that within another plugin that requires the shortcode to generate HTML display.)

I've read the related questions and none deal with a shortcode or the fact that I need to return only the image URL.

This works and returns the URL of the featured image:

add_action( 'init', 'register_featured_image_shortcode');

function register_featured_image_shortcode(){
add_shortcode('my_get_thumbsrc', 'my_get_thumbsrc');
}

function my_get_thumbsrc($id) {
global $post;
$id = ($id) ? $id : $post->ID;

if ( has_post_thumbnail($id)) {

$image_url = wp_get_attachment_image_src( get_post_thumbnail_id($id), 'inthenews-thumbnail');

return $image_url[0]; // return just the url

}
}

This doesn't work; I get an empty <img src field in page source:

add_action( 'init', 'register_featured_image_shortcode');

function register_featured_image_shortcode(){
add_shortcode('my_get_thumbsrc', 'my_get_thumbsrc');
}

function my_get_thumbsrc($id) {
global $post;
$id = ($id) ? $id : $post->ID;

if ( has_post_thumbnail($id)) {

$image_url = wp_get_attachment_image_src( get_post_thumbnail_id($id), 'inthenews-thumbnail');

return $image_url[0]; // return just the url
}
else  {
    return get_stylesheet_directory_uri() .' /white-placeholder-200x100.png';
}
}

So how to I add the fallback image white-placeholder-200x100.png with an else construct? Is return the wrong way to provide the URL? echo doesn't work.

Answer 1

First, you have a typo in the provided code: an extra space between the apostrophe and the forward slash before "white-placeholder."

Second, without examining the underlying logic in detail, I might try for the else statement:

else {

$placeholder_image = get_stylesheet_directory_uri() . '/white-placeholder-200x100.png';

return $placeholder_image;

}