Saving multiple instances of models in a rails form using CRUD - ruby-on-rails

Question

I'm trying to create a form that has multiple instances of different models at once.
I have my main model visualizations. A Visualization (:title, :cover_image) has_many Rows. A Row has_many Panes (:text_field, :image)
Basically when a user tries to create a Visualization, they can choose the cover image and title easily enough. But I get a bit confused when I come to the next two levels.
The user is prompted to create a new Row in the form and they can choose either 1, 2, or 3 Panes per Row. Each pane can take in text and an image, but Row doesn't necessarily have any attributes itself.
How can I generate multiple Rows with multiple Panes in this form? The end result will need to possess a bunch of rows consisting of many panes. Can I even do this in rails?
Thanks for any help!

Answer 1

You can do anything in rails! The best approach in my opinion is to create what is known as a Form Model since this form will have a lot going on and you don't want to bog down several models with validations and such for one view of your app. To do this you're basically going to create a class that will take all of this information in, run whatever validations you need, and then create whatever records you need in whatever models you have. To do this lets create a new file in your model folder called so_much.rb (You can make any filename you want just make sure you name the class the same as the file so Rails finds it automagically!)
Then in your so_much.rb file do:
class SoMuch
include ActiveModel::Model #This gives us rails validations & model helpers
attr_accessor :visual_title
attr_accessor :visual_cover #These are virtual attributes so you can make as many as needed to handle all of your form fields. Obviously these aren't tied to a database table so we'll run our validations and then save them to their proper models as needed below!
#Add whatever other form fields youll have
validate :some_validator_i_made
def initialize(params={})
self.visual_title = params[:visual_title]
self.visual_cover = params[:visual_cover]
#Assign whatever fields you added here
end
def some_validator_i_made
if self.visual_title.blank?
errors.add(:visual_title, "This can't be blank!")
end
end
end
Now you can go into your controller that is processing this form and do something like:
def new
#so_much = SoMuch.new
end
def create
user_input = SoMuch.new(form_params)
if user_input.valid? #This runs our validations before we try to save
#Save the params to their appropriate models
else
#errors = user_input.errors
end
end
private
def form_params
params.require(#so_much).permit(all your virtual attributes we just made here)
end
Then in your view you would set your form_for up with #so_much like:
<%= form_for #so_much do %>
whatever virtual attributes etc
<% end %>
Form Models are a bit advanced in Rails but are a life saver when it comes to larger apps where you have many different types of forms for one model and you don't want all of the clutter.