javascript - Rails 4 - JS for dependent fields with simple form -

i trying make app in rails 4.

i using simple form forms , have tried use gem 'dependent-fields-rails' hide or show subset questions based on form field of primary question.

i'm getting stuck.

i have added gems gem file for:

gem 'dependent-fields-rails' gem 'underscore-rails' 

i have updated application.js to:

//= require dependent-fields //= require underscore 

i have form has:

<%= f.simple_fields_for :project_date |pdf| %>   <%= pdf.error_notification %>                  <div class="form-inputs">                       <%= pdf.input :student_project, as: :radio_buttons, :label => "is project in students may participate?", autofocus: true %>                       <div class="js-dependent-fields" data-radio-name="project_date[student_project]" data-radio-value="true">                       <%= pdf.input :course_project, as: :radio_buttons, :label => "is project students complete credit towards course assessment?" %>                      <%= pdf.input :recurring_project, as: :radio_buttons, :label => "is project offered on recurring basis?" %>                      <%= pdf.input :frequency,  :label => "how project repeated?", :collection => ["no current plans repeat project", "each semester", "each year"] %>                     </div>                      <div class='row'>                         <div class="col-md-4">                             <%= pdf.input :start_date, :as => :date_picker, :label => "when want started?"  %>                         </div>                           <div class="col-md-4">                             <%= pdf.input :completion_date,  :as => :date_picker, :label => "when expect finish?" %>                         </div>                         <div class="col-md-4">                                       <%= pdf.input :eoi, :as => :date_picker, :label => 'when expressions of interest due?' %>                         </div>                     </div>                 </div>           <% end %>  <script type="text/javascript">   $('.datetimepicker').datetimepicker(); </script>  <script> $(document).ready(function() {     dependentfields.bind() }); </script> 

i don't know javascript.

i"m not sure if final script paragraph necessary or if gem puts code you. i'm not sure if it's supposed expressed inside script tags , don't know how give effect requirement (which set out on gem page dependent-fields):

"be sure include underscorejs , jquery in page." 

how include underscorejs , jquery in page? have them in gem file. enough or else required make work?

currently, when try form, nothing hidden. have tried swapping true value 'yes' doesnt make difference either.

<div class="js-dependent-fields" data-radio-name="project_date[student_project]" data-radio-value="true">  <div class="js-dependent-fields" data-radio-name="project_date[student_project]" data-radio-value="yes"> 

can see i've gone wrong?

i think jumping collection attribute when define radio button.

if @ documentation example, see use collection define values of radio button. use 1 of values defined set data-radio-value attribute.

try , let me know:

<div class="form-inputs">    <%= pdf.input :student_project, as: :radio_buttons, autofocus: true,       :label => "is project?", :collection => ['yes', 'no'] %>    <div class="js-dependent-fields" data-radio-value='yes'         data-radio-name="project_date[student_project]">     ...   </div>  </div> 

update

if @ this example project, application.js file includes required libraries in different order you. error.

note requiring libraries in way:

//= require dependent-fields //= require underscore 

while example project require libraries in way:

//= require underscore //= require dependent-fields 

hope help!