maple-bbs/templates/topic/reply/form.html

<div class="panel panel-default">
  {% if g.user.is_authenticated %}
  <div class="panel-heading"> {{ _('Reply this topic') }} </div>
  <div class="panel-body">
    <form action="{{ url_for('topic.reply_list',topicId=topic.id)}}" method="POST">
      {{ form.hidden_tag() }}
      {{ form.content(class='form-control',rows=4)}}
      <button class="btn btn-sm btn-primary" type="submit" style="margin-top:10px;">{{ _('Post reply') }}</button>
    </form>
  </div>
  {% else %}
  <div class="panel-body" style="border:1px dashed #337ab7;margin:5px;">
    <span class="text-center" style="display:block;width:100%;color:#999">
      <i class="fa fa-lock" style="font-size:16px;"></i>
      {{_('You need')}} <a href="{{ url_for('auth.login') }}">{{ _('Login')}}</a> {{_('before you can reply.')}}
    </span>
  </div>
  {% endif %}
</div>