app/views/instance_configuration/index.html.erb
<%= page_header :title => t("txt.views.instance_configuration.caption").titleize %>
<%= form_tag(instance_configuration_path, :method => :patch) do %>
<% @settings_by_namespace.each do |namespace, settings| %>
<fieldset>
<legend><%= t("txt.views.instance_configuration.groups.#{namespace}").titleize %></legend>
<% settings.each do |key, value| %>
<div class="form-group row">
<label class="col-form-label col-sm-4">
<%= t("txt.views.instance_configuration.settings.#{key.gsub(".", "_")}") %>
</label>
<div class="col-sm-8">
<%= text_field_tag "config[#{key}]", value, :class => 'form-control' %>
</div>
</div>
<% end %>
</fieldset>
<% end %>
<hr />
<div class="mb-5">
<%= submit_tag t("txt.common.save"), :class => "btn btn-primary" %>
</div>
<% end %>