おかずつめあわせ

リアクションボタンを追加できた。

スニペットのプラグインを入れて下記の通り対応。

add_filter('the_content','simple_reactions');
add_filter('the_excerpt','simple_reactions');

function simple_reactions($content){

    if(is_admin()) return $content;

    global $post;

    $reactions = [
        'like' => '👍 want you',
        'love' => '❤️ lover men',
        'read' => '👀 Cleanup Clean Lady'
    ];

    $buttons = '<div class="simple-reactions">';

    foreach($reactions as $key => $emoji){

        $count = (int)get_post_meta($post->ID,'reaction_'.$key,true);

        $buttons .= '
        <button class="simple-reaction-btn"
            data-post="'.$post->ID.'"
            data-reaction="'.$key.'"
            data-label="'.$emoji.'">
            '.$emoji.' '.$count.'
        </button>';
    }

    $buttons .= '</div>';

    return $content.$buttons;
}

add_action('wp_footer','simple_reactions_script');

function simple_reactions_script(){ ?>

<script>
document.addEventListener('click', async function(e){

    if(!e.target.classList.contains('simple-reaction-btn')) return;

    const btn = e.target;

    const label = btn.dataset.label;

    const form = new FormData();

    form.append('action','simple_reaction');
    form.append('post_id',btn.dataset.post);
    form.append('reaction',btn.dataset.reaction);

    const res = await fetch('<?php echo admin_url('admin-ajax.php'); ?>',{
        method:'POST',
        body:form
    });

    const count = await res.text();

    btn.innerHTML = label + ' ' + count;
});
</script>

<?php }

add_action('wp_ajax_simple_reaction','simple_reaction');
add_action('wp_ajax_nopriv_simple_reaction','simple_reaction');

function simple_reaction(){

    $post_id = (int)$_POST['post_id'];

    $reaction = sanitize_text_field($_POST['reaction']);

    $meta_key = 'reaction_'.$reaction;

    $count = (int)get_post_meta($post_id,$meta_key,true);

    $count++;

    update_post_meta($post_id,$meta_key,$count);

    echo $count;

    wp_die();
}

「外観 → カスタマイズ → 追加CSS」

.simple-reactions{
    display:flex;
    gap:10px;
    margin-top:8px;
    flex-wrap:wrap;
}

.simple-reaction-btn{
    background:none;
    border:none;
    padding:0;
    cursor:pointer;

    font-size:11px;
    line-height:1.2;

    color:#888 !important;

    opacity:0.85;
}

.simple-reaction-btn:hover{
    opacity:1;
}