movie_trailers.rb

# routes.rb
Rails.application.routes.draw do
  root 'trailers#index'

  resources :trailers do
    collection do
      get 'query'
    end
  end
end

# app/controllers/trailers_controller.rb
class TrailersController < ApplicationController
  def index
  end

  def query
    response = HTTParty.get("http://api.traileraddict.com/?film=the-dark-knight&count=8")
    trailer = response.parsed_response["trailers"]["trailer"][0]["embed"]
    respond_to do |format|
      format.json { render json: { trailer_html: trailer } }
    end
  end
end

# app/views/trailers/index.html.erb
<h1>Trailers</h1>
<%= form_tag query_trailers_path, method: 'get', remote: true, class: 'search-form' do |f| %>
  <%= label_tag do %>
    Search for trailers: <%= search_field_tag :query %>
  <% end %>
  <%= submit_tag :search %>
<% end %>

<div id="results"> </div>

<script>
  $('.search-form')
    .on('ajax:success', function(event, data) {
      $('#results').html(data.trailer_html);
    });
</script>