Conditional Output based on Manual Excerpt in Bricks

In the Bricks Facebook group a user asks:

Is it possible to only show a post’s excerpt only if it has been manually set? In my blog post template, I want to display the excerpt above the main content if the author explicitly provided one. I tried using conditions on the Excerpt element but am not sure how to set it up properly.

Yes. Follow these steps.

Step 1

Define a custom function that takes in an optional post ID and returns true if the post has a manual excerpt or false if there is none.

Add the following code (thanks to AI) in child theme‘s functions.php (w/o the opening PHP tag) or a code snippets plugin:

<?php 

function bl_has_manual_excerpt( $post_id = null ) {
    $post = get_post( $post_id );

    if ( ! $post ) {
        return false;
    }
    
    // Check if the post has an excerpt
    if ( ! empty( $post->post_excerpt ) ) {
        // Get the automatically generated excerpt
        $auto_excerpt = wp_trim_words( $post->post_content, 55, '' );
        
        // Compare the stored excerpt with the auto-generated one
        return $post->post_excerpt !== $auto_excerpt;
    }
    
    return false;
}

Step 2

Whitelist the bl_has_manual_excerpt function.

Ex.:

<?php 

add_filter( 'bricks/code/echo_function_names', function() {
  return [
    'bl_has_manual_excerpt'
  ];
} );

You should also add other functions (native or custom) being used in your Bricks instance besides bl_has_manual_excerpt. This can be checked at Bricks → Settings → Custom code by clicking the Code review button.

More info on whitelisting can be found here.

Step 3

Apply a dynamic data condition on an element in the single post template that you wish to be conditionally output depending on whether that post has a manual excerpt.

{echo:bl_has_manual_excerpt}

Check the result on the front end.