<div class="small-12 medium-6">
  <%= form_for(User.new, url: url, as: :user, method: :get) do |f| %>
    <div class="input-group">
        <%= text_field_tag :name_or_email, params[:name_or_email].to_s, placeholder: t("admin.shared.user_search.placeholder") %>
      <div class="input-group-button">
        <%= f.submit t("admin.shared.user_search.button"), class: "button" %>
      </div>
    </div>
  <% end %>
</div>

<div class="small-12 medium-6">
  <%= form_tag(url, method: :get) do |f| %>
    <div class="input-group">
        <%= text_field_tag :name_or_email, params[:name_or_email].to_s, placeholder: t("admin.shared.user_search.placeholder") %>
      <div class="input-group-button">
        <%= submit_tag t("admin.shared.user_search.button"), class: "button" %>
      </div>
    </div>
  <% end %>
</div>

Use form_tag in search form
Use form_tag in search form

This form does not depend on an object at all, so we can use a generic
tag which is model-independent.
