Making a Rails form within a calendar, collecting the date attribute to submit the form

Question

I'm a Rails novice, I've come across a little trouble and I think my problem is similar to this question, but doesn't get solved there (and doesn't seem to be best practice to use a hidden_field): Turning a calendar into a form using Rails?

I want to build a calendar in which someone tracks their miles on a bicycle by entering the miles on the specific date in which they took the trip.

I'm using https://github.com/watu/table_builder to build my calendar, it looks like this:

index.html.erb

<%= calendar_for(@miles, :year => @date.year, :month => @date.month) do |t| %>
    <%= t.head('mon', 'tue', 'wed', 'thu', 'fri', 'sat', 'sun') %>
    <%= t.day(:day_method => :day_logged) do |day, miles| %>
        <%= day.day %>
        <%= render 'form', :day => day %>
            <% miles.each do |mile| %>
                <h3><%= h(mile.distance) %></h3>
            <% end %>
    <% end %>
<% end %>

_form.html.erb

<%= form_for @mile, url: {action: "create"}, html: {class:"mile_form"} do |f| %>
<%= f.hidden_field :day_logged, day %>
<p>
    <%= f.label :distance, "Miles ridden" %>
    <%= f.number_field :distance %>
    <%= f.submit "Add" %>
</p>

trips_controller.rb

def index
    @mile = Mile.new
    @miles = Mile.find(:all)
    @date = params[:month] ? Date.parse("#{params[:month]}-01") : Date.today
end

def create
    @mile = Mile.new(params[:distance])
    if @mile.save
        redirect_to root_path
            else
                    ## ???
    end
end

mile.rb

validates :distance, presence: true, :numericality => {:only_integer => true}
validates :day_logged, presence: true

schema.rb

create_table "miles", force: true do |t|
  t.integer  "distance"
  t.date     "day_logged"
  t.datetime "created_at"
  t.datetime "updated_at"
end

I've tried the hidden field option and have been receiving this error:

NoMethodError in Trips#index   
undefined method `merge' for Sun, 26 Jan 2014:Date

I'm pretty stumped over this, and I don't think this is the best way to be doing this anyway. Any help would be greatly appreciated.

Answer 1

The second parameter to the hidden_field method is a hash of options, not a value. So instead of this:

<%= f.hidden_field :day_logged, day %>

Do this:

<%= f.hidden_field :day_logged, value: day %>

BTW, you will likely make this exact same mistake roughly 32,000 times in your career.