ajax_controller.rb

class AjaxController < ApplicationController

  skip_authorization_check

  def ncaa_teams
    if params[:term]
      teams = NcaaTeam.where('name LIKE ?', "%#{params[:term]}%").order("name ASC")
    else
      teams = NcaaTeam.all
    end
    list = teams.map {|t| Hash[ id: t.id, label: t.name, name: t.name]}
    render json: list
  end

  def nfl_teams
    if params[:term]
      teams = NflTeam.where('name LIKE ?', "%#{params[:term]}%").order("name ASC")
    else
      teams = NflTeam.all
    end
    list = teams.map {|t| Hash[ id: t.id, label: t.name, name: t.name]}
    render json: list
  end

end

application.css.scss

 *= require jquery.ui.autocomplete
 */

application.js

//= require jquery
//= require jquery.ui.autocomplete
//= require jquery_ujs
//= require responsive-tables
//= require foundation
//= require jquery.purr
//= require best_in_place
//= require sticky_footer

var load_search;
load_search = (function() {
  $('#ncaa_team_name').autocomplete({source: "/ajax/ncaa_teams"});
  $('#nfl_team_name').autocomplete({source: "/ajax/nfl_teams"});
}); 

$(document).ready(load_search);
$(document).on('page:load', load_search);

example_form.html.erb

<div class="centered">
  <%= form_tag nfl_teams_path, :method => 'get' do %>
  <p>
    <%= text_field_tag :search, params[:search], id: "nfl_team_name", placeholder: 'Find a Team' %>
    <%= submit_tag "Search", :name => nil, class: 'round button tiny' %>
  </p>
  <% end %>
</div>

<!-- 
Note that you can use any :search or params[:search] parameter that leads to your own model's search method.
Regardless of what you place in here, params[:term] will be sent to the ajax controller via a hidden request.
-->

Gemfile

gem 'jquery-ui-rails'

ncaa_team.rb

# one of my models

  def ncaa_team_name=(name)
    team = NcaaTeam.find_by_name(name)
    if team
      self.team_id = team.id
    else
      errors[:team_name] << "Invalid name entered"
    end
  end

  def ncaa_team_name
    NcaaTeam.find(team_id).name if team_id
  end

nfl_team.rb

# another one of my models

  def nfl_team_name=(name)
    team = NflTeam.find_by_name(name)
    if team
      self.team_id = team.id
    else
      errors[:team_name] << "Invalid name entered"
    end
  end

  def nfl_team_name
    NflTeam.find(team_id).name if team_id
  end

routes.rb

match '/ajax/ncaa_teams' => "ajax#ncaa_teams", via: :get
match '/ajax/nfl_teams' => "ajax#nfl_teams", via: :get