Generate a excerpt from an ACF-wysiwyg-field

Question

I have an ACF-field, that gives an output like this:

<p>Lorem ipsum dolor sit amet, consectetur adipiscing elit.</p>
<p><img class="alignnone size-large wp-image-48" src="http://example.org/wp-content/uploads/2019/01/foo-bar.jpg" alt="" width="1024" height="640" /></p>
<p>Sed lacinia enim a <strong>est aliquet</strong>, et accumsan ex pellentesque. </p>
<p>Adipiscing elit, lorem ipsum dolor sit amet, consectetur.</p>

... Both images and text.

With wp_html_excerpt I can remove all tags, so I get one long text-blurp.

But with WordPress' native excerpts, then it doesn't remove line-breaks or bold text, which I find nice.

How would I go about achieving, getting an excerpt like that, from my ACF-wysiwyg-field?

So ideally, I would call my function like this: create_neat_excerpt( $html, 15 ); and get an output like this (from above-given input):

<p>Lorem ipsum dolor sit amet, consectetur adipiscing elit.</p>
<p>Sed lacinia enim a <strong>est aliquet</strong>, et accumsan...</p>

Addition: My current attempt

$project_desc = get_field( 'project_description' );

if( !empty( $project_desc ) ):
  $trimmed_text = wp_html_excerpt( $project_desc, 800 );
  $last_space = strrpos( $trimmed_text, ' ' );
  $modified_trimmed_text = substr( $trimmed_text, 0, $last_space );
  echo $modified_trimmed_text . '...';
endif; 

Answer 1

You can provide your own implementation of wp_trim_excerpt which is responsible for trimming and stripping HTML tags (it uses wp_strip_all_tags),

By copying the function source code and applying the change that you want (which is keeping the <p> and <strong> tags (or any additional tags as you wish) and it will work nicely.

I copied the function for you and applied the change of allowing <p> and <strong> to be on your final excerpt. (You should put this code in your functions.php file)

function wp_trim_excerpt_modified($text, $content_length = 55, $remove_breaks = false) {
    if ( '' != $text ) {
        $text = strip_shortcodes( $text );
        $text = excerpt_remove_blocks( $text );
        $text = apply_filters( 'the_content', $text );
        $text = str_replace(']]>', ']]>', $text);
        $num_words = $content_length;
        $more = $excerpt_more ? $excerpt_more : null;
        if ( null === $more ) {
            $more = __( '…' );
        }
        $original_text = $text;
        $text = preg_replace( '@<(script|style)[^>]*?>.*?</\\1>@si', '', $text );

        // Here is our modification
        // Allow <p> and <strong>
        $text = strip_tags($text, '<p>,<strong>');

        if ( $remove_breaks )
            $text = preg_replace('/[\r\n\t ]+/', ' ', $text);
        $text = trim( $text );
        if ( strpos( _x( 'words', 'Word count type. Do not translate!' ), 'characters' ) === 0 && preg_match( '/^utf\-?8$/i', get_option( 'blog_charset' ) ) ) {
            $text = trim( preg_replace( "/[\n\r\t ]+/", ' ', $text ), ' ' );
            preg_match_all( '/./u', $text, $words_array );
            $words_array = array_slice( $words_array[0], 0, $num_words + 1 );
            $sep = '';
        } else {
            $words_array = preg_split( "/[\n\r\t ]+/", $text, $num_words + 1, PREG_SPLIT_NO_EMPTY );
            $sep = ' ';
        }
        if ( count( $words_array ) > $num_words ) {
            array_pop( $words_array );
            $text = implode( $sep, $words_array );
            $text = $text . $more;
        } else {
            $text = implode( $sep, $words_array );
        }
    }
    return $text;
}

Notice the line that is doing the stripping:

Line:22 $text = strip_tags($text, '<p>,<strong>');

And your code should be like this:

$project_desc = get_field( 'project_description' );
if( !empty( $project_desc ) ):
    $trimmed_text = wp_trim_excerpt_modified( $project_desc, 15 );
    $last_space = strrpos( $trimmed_text, ' ' );
    $modified_trimmed_text = substr( $trimmed_text, 0, $last_space );
    echo $modified_trimmed_text . '...';
endif; 

For more information, you can checkout this answer on stackoverflow it is more detailed.

Answer 2

using apply_filters( 'the_excerpt', get_field( 'project_description' ) ); is close, but it's missing a vital step in getting you where you want. the core excerpt builder runs another filter before it hits the_excerpt. it's get_the_excerpt and on that filter is a call to wp_trim_excerpt() which runs wp_trim_words(). if you look at that function you will see it runs wp_strip_all_tags() before trimming content to 55 words. This is the part you are missing to get your content to look like a regular excerpt without any images. I haven't tested the below but it should work without too much modification needed.

$raw_content = get_field( 'project_description' );
$trimmed_content = wp_trim_words($raw_content);
$clean_excerpt = apply_filters('the_excerpt', $trimmed_content);

echo $clean_excerpt;

Clean that up however you like, I spread it all out for readability.

EDIT: wp_trim_excerpt() only runs all the fun filters if it's pulling from post content. replaced with wp_trim_words()

Answer 3

Use the_excerpt filter (see Codex)

apply_filters( 'the_excerpt', get_field( 'my-wysiwyg-field' ) );