Question

Rails newbie here struggling with a small project. I am creating a simple ship building tool for a board game I like as an exercise and I am a bit lost.

What do I want to do?
-After creating my Ship model record I want to create the Traits model record that will be associated with the Ship model. After updating a Ship model record I want to update or create the Traits model that will be associated with the Ship model record.

What have I tried?
– Adding the traits to each Ship model record as column variables. I do not think that this is the most effecient way of storing the traits for each of my Ship models. I have a Traits model set up but I do not know how to navigate to it and associate it with my Ship models

What would I like to have when finished?
– An array that is stored in each Ship model record that will list the attributes for each ship with their corresponding values,

i.e. if

trait_list = [trait1 => t1, trait2 => t2, trait3 => t3, trait4 => t4]

ship_traits = [t1, t4].

In the end I would be able to call the traits on my ship diagram page without having to iterate through every single trait, just the ones pertinent to my current model.

I am lost on how I should set up the associations between the models. Any help or kind advice on directions I should be researching would be warmly welcomed. I apologize in advance for my vagueness, again I am a complete newbie.

Cheers,
Nick

Answer 1

I’m not 100% sure this would solve your problem, but you could do something like this:

class Ship < ActiveRecord::Base
  has_many :traits
  accepts_nested_attributes_for :traits
end

class Trait < ActiveRecord::Base
  belongs_to :ship
end


# In your form
- form_for @ship do |f|
  - f.fields_for :traits do |ff|
    = ff.label :trait_name
    = ff.text_field :trait_name

# this will return all the traits for model defined as @ship
@ship.traits 

I know it’s not an array within the Ship model, but I hear it’s a little tricky to set a column in a model to be array. If you want the traits to be unique (as in many ships can have many traits and these traits can belong to many different ships), then you’re going to have a has_many :through relationship. If that’s the case, let me know and I’ll answer again. Or you can take a look at this: http://guides.rubyonrails.org/association_basics.html