personal-activity/app/views/admin/activities/index.html.erb

<script src="https://kit.fontawesome.com/1fa49cfdc9.js" crossorigin="anonymous"></script>
<table class="table main-list">
    <thead>
        <tr>
            <th class="span1"><%= t("personal_activity.participant") %></th>
            <th class="span1"><%= t("personal_activity.year") %></th>
            <th class="span5"><%= t("personal_activity.activity_name") %></th>
            <th class="span1"><%= t("personal_activity.activity_organizer") %></th>
        </tr>
    </thead>
    <tbody id="tbody_activity" class="sort-holder">
        <%= render 'activity' %>
    </tbody>
</table>

<div class="bottomnav clearfix">

    <!-- buttons -->
    <div class="action pull-right">
        <div class="dropup upload-button">
            <button class="btn btn-primary dropdown-toggle" type="button" data-toggle="dropdown">
                <i class="icon-upload-alt icon-white"></i><%= t('personal_activity.upload') %>
            <span class="caret"></span>
            </button>
            <div class="dropdown-menu upload-box">
                <form action="/admin/activities/import_from_excel" method="post" enctype="multipart/form-data">
                  <%= hidden_field_tag :authenticity_token, form_authenticity_token %>
                  <input type="file" name="import_file" >
                    <button class="btn btn-primary" type="submit"><%= t(:submit) %></button>
                    <a class="" href="/admin/activities/download_excel_format.xlsx">Download excel format</a>
                </form>
            </div>
        </div>
        <%= link_to content_tag(:i, nil, :class => 'icon-plus icon-white') + t(:new_), new_admin_activity_path, :class => 'btn btn-primary' %>
    </div>

    <!-- pagination -->
    <div class="pagination pagination-centered">
        <%= content_tag :div, paginate(@activities), class: "pagination pagination-centered" %>
    </div>
</div>

<% if params[:error] == "1" %>
  <script type="text/javascript">
    alert("File cannot be imported. File has more than 500 entries. Please seperate the entries in different files.");
    window.location.href = "<%= admin_activities_url %>"
  </script>
<% end %>