ruby on rails - Simple form text input fields as part of an array -

so have 3 text input fields , each 1 represents co-ordinate , stored in array format [x, y, z] in model.

i trying use input fields work produce array submitted form. code currently:

=f.input_field :coordinates[0], value: "1" =f.input_field :coordinates[1], value: "2" =f.input_field :coordinates[2], value: "3" 

so hoping can use coordinates param in controller save database. issue setup html produced <input value="1" name="shape[o]" id="shape_o"> when should <input value="1" name="shape[coordinates][]" id="shape_coordinates_0">

n.b. have serialize :coordinates in model

try set custom attributes directly this:

= f.input_field :coordinates, input_html: { value: 1,                                             id: "shape_coordinates_0",                                              name: "shape[coordinates][]" } 

but suggest create attr_readers in model each coordinate , unite in array:

# model: class shape < activerecord::base   attr_reader :x, :y, :z #since want serialize    before_create :build_coordinates    private    def build_coordinates     self.coordinates = [x, y, z]   end end 

in case view easy like:

=f.input_field :x, value: "1" =f.input_field :y, value: "2" =f.input_field :z, value: "3"