// Contact Form7のお問い合せフォーム項目にひらがなが無ければ送信不可
add_filter('wpcf7_validate_textarea', 'wpcf7_validation_textarea_hiragana', 10, 2);
add_filter('wpcf7_validate_textarea*', 'wpcf7_validation_textarea_hiragana', 10, 2);
function wpcf7_validation_textarea_hiragana($result, $tag)
{
  $name = $tag['name'];
  $value = (isset($_POST[$name])) ? (string) $_POST[$name] : '';
  if ($value !== '' && !preg_match('/[ぁ-ん]/u', $value)) {
    $result['valid'] = false;
    $result['reason'] = array($name => 'エラー：こちらの内容は送信できません。');
  }
  return $result;
}{"id":183,"count":1,"description":"","link":"https:\/\/one-foodie.com\/area\/%e4%bb%a3%e3%80%85%e6%9c%a8%e4%b8%8a%e5%8e%9f\/","name":"\u4ee3\u3005\u6728\u4e0a\u539f","slug":"%e4%bb%a3%e3%80%85%e6%9c%a8%e4%b8%8a%e5%8e%9f","taxonomy":"area","parent":28,"meta":[],"_links":{"self":[{"href":"https:\/\/one-foodie.com\/wp-json\/wp\/v2\/area\/183"}],"collection":[{"href":"https:\/\/one-foodie.com\/wp-json\/wp\/v2\/area"}],"about":[{"href":"https:\/\/one-foodie.com\/wp-json\/wp\/v2\/taxonomies\/area"}],"up":[{"embeddable":true,"href":"https:\/\/one-foodie.com\/wp-json\/wp\/v2\/area\/28"}],"wp:post_type":[{"href":"https:\/\/one-foodie.com\/wp-json\/wp\/v2\/posts?area=183"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}