Rails ActiveModel - 更新嵌套属性并添加新属性

Question

I'm a Rails beginner. What I have right now is a Form that has_many approvals.

class Form < ApplicationRecord
 has_many :form_results
 has_many :approvals

 accepts_nested_attributes_for :approvals
end

class Approval < ApplicationRecord
 belongs_to :form
 belongs_to :user
end

When editing :approvals I need to run some logic. Approvals are sequential so they have an order_index as well as an active key (similar to a soft delete). When a FormResult gets created, multiple FormResultApprovals get created based on the data in Approvals for that form. What I need to do when updating the Form, I need to see if an Approval has changed for an already existing order_index . If it has I need to mark the existing Approval as active: false and create a new Approval for that order_index .

I'm wondering what the "Rails way" of doing this is? I have a big chunk of logic that checks all of this and works, but as I discover more and more Rails helpers, I can't help but think there's a better way to do this.

The code I have now looks like

# Grab all current approvals for form that is being edited
# Diff the current against the new ones in the attributes
# If any have of the current approvals have the same id as the "new" ones in the attributes but have a different user associated to them, set active to false on the current approval with that id, and insert a new approval associated to the new user.

I'm using SimpleForm.

Answer 1

So this is what I came up with.

class Approval < ApplicationRecord
  default_scope { where(active: true) }
  belongs_to :form_module
  belongs_to :user, optional: true
  belongs_to :group, optional: true

  before_update :handle_change_in_approver


  def create_copy_model
    new_approval = Approval.new(order_index: order_index, user_id: user_id, group_id: group_id, form_module_id: form_module_id)
    new_approval.save
    self.active = false
    self.user_id = user_id_was
    self.group_id = group_id_was
    save
  end

  def handle_change_in_approver
    # User ID changed
    if user_id_was != user_id
      create_copy_model
    elsif group_id_was != group_id
      create_copy_model
    end
    form.form_results.each(&:create_approvals_for_approval_change)
  end
end

Basically, whenever a record is updated I run a callback before the update that checks to see if the group_id or user_id has changed. If it has then I create a new Approval based on the update params, and the return the current Approval back to it's original state, marking it as active: false . I'm pretty stoked with how this turned out.