Ruby on Rails Form for Calculating Dice Rolls - ruby-on-rails

Question

I am creating a web application as a training project that will take three inputs (Integer values for number of dice, number of sides and number of rolls) and input that into a series of tables that will facilitate calculations and the output of the results, and the saving of historical data (past rolls.)
I'm stuck.
Here is my ERB for the form:
<%= form_for(#run) do |f| %>
How many dice: <%= f.number_field :die_count, :placeholder => "# of dice" %><br>
How many sides: <%= f.number_field :die_sides, :placeholder => "# of sides" %><br>
How many rolls: <%= f.number_field :rolls, :placeholder => "# of rolls" %><br>
<%= f.submit "Roll!" %>
<% end %>
Here's my Model:
class Run < ActiveRecord::Base
has_many :rolls
belongs_to :user
validates_presence_of :die_count, :rolls, :die_sides
validates_numericality_of :die_count, :die_sides, :rolls
end
Here's my pertinent Controller info:
def new
#run = Run.new
end
def create
#run = Run.new(run_params)
end
private
def run_params
params.require(:run).permit(:die_count, :die_sides, :rolls)
end
For good measure, here's the migrate for making my DB table:
class CreateRuns < ActiveRecord::Migration
def change
create_table :runs do |t|
t.integer :die_count
t.integer :die_sides
t.integer :roll_count
t.timestamps null: false
end
end
end
At this point, I just want it to create a new record in the Run model. Here's the error I'm getting with the input of 5, 5, and 5 into the number_fields and click my submit button:
If I am reading this correctly, my application wants to iterate through the individual numbers as if they were arrays, but it can't because they are strings. This confuses me because they aren't strings in the first place. They are integers.
Pulling my hair out on this one.

Answer 1

:rolls is a reference to another model called Roll (have you created it?).
:roll_count is the attribute of your Run model that defines the number of rolls (as visible in your migration table).
They are two very different things, even though it stands to reason that :roll_count should in theory be equal to the number of Roll records your Run record 'owns'.
In your form, replace :rolls by :roll_count. Do the same in the run_params method in your controller. And also in the two validations in your model. (checklist: that's 4 places where you need to modify that symbol name).
In your controller, also change the content of your create method to #run = Run.create(run_params).
Edited (clarity): Run.new(params) creates a new instance of a Run object but doesn't save it in your DB. Run.create(params) creates the object AND saves it.
Finally, in your model, comment out the has_many :rolls until you have actually implemented the Roll model (no pun intended!) ; do the same for belongs_to :user if the User model is not implemented either.
After these changes, your form should normally work and data should be saved in your runs database table.

Answer 2

I believe you meant to replace rolls with roll_count everywhere in your code.
How many rolls: <%= f.number_field :roll_count, :placeholder => "# of rolls" %><br>
and
validates_presence_of :die_count, :roll_count, :die_sides
validates_numericality_of :die_count, :die_sides, :roll_count
and
def run_params
params.require(:run).permit(:die_count, :die_sides, :roll_count)
end