HTML5 Datalist using Ruby on Rails form_for

_form.html.erb

<%= form_for @person do |f| %>
  <%= f.label :first_name, "First Name" %>:
  <%= f.text_field :first_name, list: 'first-name' %>
  <datalist id="first-name">
    <% Person.all.each do |person| %>
      <option value="<%= person.first_name %>"></option>
    <% end %>
  </datalist>
  <%= f.submit %>
<% end %>

You may also want to do distinct:

<% Person.select(:first_name).distinct.each do |person| %>

better use

datalist#first-name
  = options_for_select(Person.pluck(:first_name).uniq, @person.first_name)

It is written in Slim but you get the idea ;)
It's way more compact and easier to read imo.

How can we test the view that results from the datalist options. For e.g. in case we have following 4 options ---

       1. fruit/apple
       2. fruit/guava
       3. fruit/melon
       4. fruit/grapes

and I select fruit/apple in the text_field, the list under the text_filed will also show fruit/apple. How to write an rspec test that verifies that the list under the text_field is showing fruit/apple ? This is just to validate that the datalist is working.

Very good! Thanks @brunopgalvao @joleb

Thanks for this @brunopgalvao!!