multiparameter error with datetime_select

Question

I have the following code in my form.

<%= f.datetime_select(:date_time, :prompt => {:day => \'Day\', :month => \'Month\', :year => \'Year\'},          


        

Answer 1

I had the same problem using a date dropdown that wasn't backed by a database attribute. I wrote a little Rack middleware to cope with the problem:

class DateParamsParser
  def initialize(app)
    @app = app
  end

  def call(env)
    if %w{POST PUT}.include? env['REQUEST_METHOD']
      params = Rack::Utils.parse_query(env["rack.input"].read, "&")

      # selects only relevant params like 'date1(1i)'
      filtered_params = params.select{ |key, value| key =~ /\(\di\)/ }
      # delete date params
      filtered_params.each { |key, value| params.delete(key) }

      # returns something like {'date1' => [2012, 5, 14], 'date2' => [2002, 3, 28]}
      date_array_params = filtered_params.sort.reduce({}) do |array_params, keyvalue|
        date_key = keyvalue.first.match(/(.+)\(/)[1] + ']'
        array_params[date_key] ||= []
        array_params[date_key] << keyvalue.last
        array_params
      end

      # Creates params with date strings like {'date1' => '2012-5-14', 'date2' => '2002-3-28'}
      date_params = Hash[date_array_params.map{ |key, date_array| [key, date_array.join('-')] }]

      params.merge! date_params
      env["rack.input"] = StringIO.new(Rack::Utils.build_query(params))
      env["rack.input"].rewind
    end

    @app.call(env)
  end
end

And in application.rb I put

config.middleware.insert_before ActionDispatch::ParamsParser, "DateParamsParser"

Note that I only build a date string here. So if you also require time you'll need to build the date_params differently.