Ruby on rails DateTime require param

Question

Hi there i just need to require the param start_hour from my form so that i compare it to the database and check if it exist, but when i requiere the param that is in the form like

<%= f.datetime_select :start_hour, { :order => [:month, :day, :year, :hour, :minute], :prompt => { :day => 'Dia', :month => 'Mes', :year => 'Ano', :hour => 'Hora', :minute => 'Minuto' } }, {:class => "form-control", :style => "display: inline-block;
    width: auto;
    vertical-align: middle;"}  %>

i get that as nil in my controller, how can i require a datetime form then? many thanks. Here is my controller

def create
        @start_hour     =   params[:courtesie][:start_hour]
        @lesson_check   =   Lesson.find_by(start_date: @start_hour)
        if @lesson_check.present?
            @new_courtesie  =   Courtesie.new(courtesie_params)
            @new_schedule   =   Schedule.new()
            @new_schedule.options   =   params[:courtesie][:name]
            @new_schedule.lesson_id =   @lesson_check.id
            @new_schedule.user_id   =   current_user.id

            if @new_courtesie.save && @new_schedule.save
                flash[:success] = "Cortesia agendada"
                redirect_to     cortesias_path
            end
        else
            flash[:warning] =   @start_hour
            redirect_to cortesias_path
        end

end

form code

<%= form_for(:courtesie, html: { class: "form-horizontal" } ) do |f| %>
                                                  <div class="form-group">
                                                    <label class="control-label col-md-2" for="sitename"> Nombre cortesia
                                                    </label>
                                                    <div class="col-md-9">
                                                      <%= f.text_field :name, class: 'form-control' %>
                                                    </div>
                                                  </div> 

                                                  <div class="form-group">
                                                    <label class="col-lg-2 control-label" for="sitename"> Fecha cortesia</label>

                                                    <div class="col-lg-10">
<%= f.datetime_select :start_hour, { :order => [:month, :day, :year, :hour, :minute], :prompt => { :day => 'Dia', :month => 'Mes', :year => 'Ano', :hour => 'Hora', :minute => 'Minuto' } }, {:class => "form-control", :style => "display: inline-block;
    width: auto;
    vertical-align: middle;"}  %>
                                                    </div>

                                                  </div> 

                                                  <div class="form-group">
                                                    <label class="control-label col-md-2" for="sitename"> Telefono </label>
                                                    <div class="col-md-5">
                                                      <%= f.number_field :phone, class: 'form-control' %>
                                                    </div>
                                                  </div>
                                                  <div class="form-group">
                                                    <label class="control-label col-md-2" for="sitename"> Email </label>
                                                    <div class="col-md-5">
                                                      <%= f.text_field :email, class: 'form-control' %>
                                                    </div>
                                                  </div> 
                                                  <div class="form-group">
                                                     <div class="col-lg-9 col-lg-offset-2">
                                                     <%= f.submit "Guardar", class: "btn btn-primary" %>
                                                        <button type="reset" class="btn btn-default">Reiniciar</button>
                                                     </div>
                                                  </div>
                                      <% end %>

Answer 1

Check if you set the parameter in your strong parameters.

def courtesie_params
  params.require(:courtesie).permit(:start_hour, ...)
end

If it's not permitted it'll be nil.

Answer 2

I assume you have permitted the start_hour atrribute in the strong parameters. Unlike the other fields, you can't access the values in a date_time field like params[:courtesie][:start_hour]

To have a sense of what I am talking about, replace the code in your create method with

def create
  render text: courtesie_params
end

Now if you submit the form, the form data would be displayed as the response.

This is what the form data would look like

{"name"=>"what", "start_time(1i)"=>"2016", "start_time(2i)"=>"8", "start_time(3i)"=>"9", "start_time(4i)"=>"23", "start_time(5i)"=>"40"}

Well, you could have a lot more values but lets focus on the datetime values. You can see where the selected values are stored. Thats why params[:courtesie][:start_hour] is nil.

So, you need to retrieve the values like

datetime_params = params[:courtesie]
year = datetime_params["start_time(1i)"]
month = datetime_params["start_time(2i)"]
day = datetime_params["start_time(3i)"]
hour = datetime_params["start_time(4i)"]
minute = datetime_params["start_time(5i)"]

Now to compare two datetimes, you actually need to convert the collected values to a datetime .

@start_hour = DateTime.new(year, month, day, hour, minute)

Now you can use this to query a datetime value and compare with other datetime values.

Hope this helps!