Content (PHP + HTML) snippets

A Content snippet outputs something. It is the type to reach for when you want a tracking tag in the header, a promo bar under the opening body tag, a disclaimer after every post, or a reusable block you place with a shortcode.

Writing one

Write HTML, and drop into PHP with <?php … ?> wherever you need it. Unlike a Functions snippet, there is no opening tag to omit; the snippet starts in HTML mode.

<div class="ship-bar">
    Free shipping on orders over $50, today only.
</div>

Mixed:

<div class="greeting">
    <?php if ( is_user_logged_in() ) : ?>
        Welcome back, <?php echo esc_html( wp_get_current_user()->display_name ); ?>.
    <?php else : ?>
        <a href="<?php echo esc_url( wp_login_url() ); ?>">Sign in</a>
    <?php endif; ?>
</div>

Escape anything dynamic, exactly as you would in a theme template. esc_html(), esc_attr() and esc_url() are all available.

Run locations

All of the site-wide locations are front end only. For output in the admin, use a Scripts snippet with an admin run location, or a Functions snippet hooked to an admin action.

Before and After Content

These two attach to the the_content filter, and only fire when all of the following are true:

• the request is for a single post, page or custom post type (is_singular())
• the filter is running inside the main loop (in_the_loop() and is_main_query())

That combination is deliberate. Without it, your markup would also appear in excerpt widgets, related post blocks, RSS output and anywhere else a theme or plugin runs the_content on secondary content.

Output is captured and concatenated onto the content. If your snippet prints nothing, the content is returned untouched.

Shortcode

Setting the run location to Shortcode means the snippet never runs on its own. It runs where you place the shortcode. This has its own page: Shortcodes.

Priority

Priority applies to the underlying hook, so it controls the order of two snippets on the same location, and the order relative to other plugins on wp_head, wp_footer or the_content. Lower runs first. See Priority.

For Before Content in particular, priority interacts with everything else filtering the_content. wpautop runs at 10, so a snippet at priority 9 sees raw content and one at 11 sees paragraph-wrapped content.

Examples

Google Analytics 4, Site Wide Header

<script async src="https://www.googletagmanager.com/gtag/js?id=G-XXXXXXX"></script>
<script>
  window.dataLayer = window.dataLayer || [];
  function gtag(){dataLayer.push(arguments);}
  gtag('js', new Date());
  gtag('config', 'G-XXXXXXX');
</script>

Google Tag Manager noscript, Site Wide Body Open

<noscript>
  <iframe src="https://www.googletagmanager.com/ns.html?id=GTM-XXXXXX"
          height="0" width="0" style="display:none;visibility:hidden"></iframe>
</noscript>

A newsletter prompt after every blog post, After Content

<?php if ( 'post' === get_post_type() ) : ?>
    <aside class="post-cta">
        <h3>Liked this?</h3>
        <p>Get the next one by email.</p>
        <?php echo do_shortcode( '[my_signup_form]' ); ?>
    </aside>
<?php endif; ?>

Pair that with conditional logic instead of the if when the rule is something the condition builder already covers, and keep PHP for logic it does not.

JSON-LD schema, Site Wide Header

<script type="application/ld+json">
{
  "@context": "https://schema.org",
  "@type": "Organization",
  "name": "<?php echo esc_js( get_bloginfo( 'name' ) ); ?>",
  "url": "<?php echo esc_url( home_url( '/' ) ); ?>"
}
</script>