Question

I’ve always wondered what do you guys do for filling out dropdown menus in rails, and not have the code splattered in the view. Do you guys make a pivot table? Do you make a class and add methods to return arrays?

I always wonder how other people make them work, for example the other way I need to fill a combo box with all the countries I made a class called DropDownFiller, and added a method called fill_countries that would return an array with all the countries.

What are the best practices regarding this or how do you do it?

Answer 1

The helper options_for_select takes an array of options and builds the select. From the docs:

options_for_select([["Dollar", "$"], ["Kroner", "DKK"]])
  <option value="$">Dollar</option>\n<option value="DKK">Kroner</option>

options_for_select([ "VISA", "MasterCard" ], "MasterCard")
  <option>VISA</option>\n<option selected="selected">MasterCard</option>

options_for_select({ "Basic" => "$20", "Plus" => "$40" }, "$40")
  <option value="$20">Basic</option>\n<option value="$40" selected="selected">Plus</option>

options_for_select([ "VISA", "MasterCard", "Discover" ], ["VISA", "Discover"])
  <option selected="selected">VISA</option>\n<option>MasterCard</option>\n<option selected="selected">Discover</option>

There are more detailed examples in the documentation.

Depending on how your data is set up, it can be easy to fill a list. For example:

options_for_select Country.select(:name).all.map { |c| c.name }

or for custom values

options_for_select Country.all.map { |c| [c.name, c.code] }

Something else I’ve seen done a few times is defining a helper method in the model that returns the correct values:

class Country
  # awesome country logic goes here!

  def self.array_for_select
    select(:name).all.map { |c| c.name }
  end
end

# a long time ago in a view far far away
options_for_select Country.array_for_select