Ruby on rails: Updating attribute on an association - ruby-on-rails

Question

In my controller I have the following:
def sort
params[:order].each do |key,value|
Question.find(value[:id]).update_attribute(:order,value[:order])
end
render :nothing => true
end
This works perfectly to update the order column for the 'Question' item.
However i've now moved the order column to a new table 'question_sections' which is associated to Questions.
class Question < ActiveRecord::Base
has_many :sections, :through => :question_sections
belongs_to :section
has_many :question_sections
default_scope { order(order: :asc) }
accepts_nested_attributes_for :section, :reject_if => :all_blank, allow_destroy: true
accepts_nested_attributes_for :question_sections, :reject_if => :all_blank, allow_destroy: true
end
I'm trying to adapt the sort function to update the 'order' column in 'question_sections' but am having trouble with it.
Any help on what the function should look like?

Answer 1

In case you are using nested attributes, you shoud call the includes method, and then iterate over each question_sections:
def sort
params[:order].each do |key,value|
questions = Question.includes(:question_sections).find(value[:id])
questions.question_sections.each { |q| q.update_attribute(:order,value[:order]) }
end
render :nothing => true
end
This breaks the problems into 2 parts, load all the question_sections needed:
1) Load all the question_sections of a question:
questions = Question.includes(:question_sections).find(value[:id])
Question Load
SELECT "questions".* FROM "questions" WHERE "questions"."id" = ? LIMIT 1 [["id", 1]]
QuestionSections Load
SELECT "question_sections".* FROM "question_sections" WHERE "question_sections"."question_id" IN (1)
2) update this question_sections
questions.question_sections.each { |q| q.update_attribute(:order,value[:order]) }
QuestionSections Update
UPDATE "question_sections" SET "order" = ?, "updated_at" = ? WHERE "question_sections"."id" = ? [["order", "different order now"], ["updated_at", "2017-03-09 13:24:42.452593"], ["id", 1]]

Answer 2

I think if you are using nested_attributes for Question model here then Rails should automatically update the nested params for QuestionSection
The controller should look something like this:
def sort
#question = Question.find_by(id: params[:id])
#question.update_attributes(question_params)
end
private
def question_params
params.require(:question).permit!
end
The parameters received to the controller should be like :
params = { question: {
abc: 'abc', question_sections_attributes: [
{ order_id: 1, ... },
{ order_id: 2, ... },
{ order_id: 3, ... }
]
}}
I hope this helps :)