Rails - content_tagの使い方
content_tagメモ
before
<div class="alert alert-<%= message_type %>"><%= message %></div>
after
<%= content_tag(:div, message, class: "alert alert-#{message_type}") %>
content_tagメモ
<div class="alert alert-<%= message_type %>"><%= message %></div>
<%= content_tag(:div, message, class: "alert alert-#{message_type}") %>