app/views/catalog/_search_form.html.erb
<%= form_tag search_form_action, method: :get, class: "form-horizontal search-form", id: "search-form-header", role: "search" do %>
<%= render_hash_as_hidden_fields(search_state.params_for_search.except(:q, :search_field, :qt, :page, :utf8)) %>
<%= hidden_field_tag :search_field, 'all_fields' %>
<div class="form-group">
<label class="control-label col-sm-3" for="search-field-header">
<%= t("hyrax.search.form.q.label", application_name: application_name) %>
</label>
<div class="input-group">
<%= text_field_tag :q, current_search_parameters , class: "q form-control", id: "search-field-header", placeholder: t("hyrax.search.form.q.placeholder") %>
<div class="input-group-btn">
<button type="submit" class="btn btn-primary" id="search-submit-header">
<%= t('hyrax.search.button.html') %>
</button>
</div><!-- /.input-group-btn -->
</div><!-- /.input-group -->
</div><!-- /.form-group -->
<% end %>