Cocoonのタイトル変更関数

title_parts_custom.php

function title_parts_custom( $title ){
  $site_name = trim( get_bloginfo('name') );
  $title['tagline'] = '';

  if(is_front_page()){ //フロントページ
    //自由形式タイトルの場合
    if (is_free_front_page_title()) {
      $title['title'] = esc_html( get_free_front_page_title() );
    } else {//自由形式でないとき
      $title['title'] = $site_name;
      $title['site'] = '';

      if ( is_tagline_to_front_page_title() )://キャッチフレーズを追加する場合
        $title['tagline'] = trim( get_bloginfo('description') );
      endif;
    }

  } elseif (is_singular()) { //投稿・固定ページ
    $title['title'] = trim( get_the_title() );
    //SEO向けのタイトルが設定されているとき
    if (get_the_page_seo_title()) {
      $title['title'] = get_the_page_seo_title();
    }
    $title['site'] = '';
    if ($simplified_site_name = get_simplified_site_name()) {
      $site_name = $simplified_site_name;
    }
    switch (get_singular_page_title_format()) {
      case 'pagetitle_sitename':
        $title['site'] = $site_name;
        break;
      case 'sitename_pagetitle':
        $title['title'] = $site_name;
        $title['site'] = trim( get_the_title() );
        break;
    }
    // if ( is_site_name_to_singular_title() )://サイト名を追加する場合
    //   $title['site'] = $site_name;
    // endif;
  } elseif (is_category()) { //カテゴリー
    $cat_id = get_query_var('cat');
    $cat_name = $title['title'];
    if ($cat_id && get_category_title($cat_id)) {
      $cat_name = get_category_title($cat_id);
    }
    $title['site'] = '';
    switch (get_category_page_title_format()) {
      case 'category_sitename':
        $title['title'] = $cat_name;
        $title['site'] = $site_name;
        break;
      case 'sitename_category':
        $title['title'] = $site_name;
        $title['site'] = $cat_name;
        break;
    }
  } elseif (is_404()) {
    $title['title'] = get_404_page_title();
  };

  return $title;
}