Always Show Excerpts

A WordPress plugin that lets you show the Post excerpt instead of the full content.

First published October 28th, 2019 2 minute reading time of 530 words (inc code) Code available at codeberg.org and the last commit was April 9th, 2024 Plugin available at WordPress

Intro

While developing the Keep Pagination in Same Taxonomy plugin, I discovered that the default 2017 WP theme showed the full post in its indexes. So, I wrote this plugin to force it to show excerpts instead so I could see what I was doing in the first place…

Along with my usual plugin code (initialisation and configuration from the “Reading” settings page), we put our hook late on into the_content call so we can check that we really want to be displaying the full post content.

add_filter('the_content', array($this, 'excerpt_not_content'), 99);

excerpt_not_content()

Rather than simply checking is_archive() - which misses out the home page and search results anyway - we opt for a finer grained control over which particular types of archive indexes will show excerpts.

public function excerpt_not_content($output) {
    $excerpt = false;

    foreach ($this->settings as $type => $active) {
        if ($active != false) {
            // test accordingly
            switch ($type) {
                case 'author':      if (is_author()) $excerpt = true;
                                    break;
                case 'category':    if (is_category()) $excerpt = true;
                                    break;
                case 'cpt':         if (is_post_type_archive()) $excerpt = true;
                                    break;
                case 'date':        if (is_date()) $excerpt = true;
                                    break;
                case 'home':        if (is_home()) $excerpt = true;
                                    break;
                case 'search':      if (is_search()) $excerpt = true;
                                    break;
                case 'tag':         if (is_tag()) $excerpt = true;
                                    break;
                case 'tax':         if (is_tax()) $excerpt = true;
                                    break;
            }
            // don't bother continuing to test if we've already decided
            if ($excerpt) break;
        }
    }        

    if ($excerpt) {
        // https://wordpress.stackexchange.com/a/77947/25187
        remove_filter('the_content', array($this, 'excerpt_not_content'), 99);
        $output = apply_filters('the_excerpt', get_the_excerpt());
        add_filter('the_content', array($this, 'excerpt_not_content'), 99);
    }

    return $output;
}

And, to avoid recursion, remember to remove a filter that is currently altering something before calling a filter that will alter the same something that will call a filter to alter the something that will call a filter to alter …