rails exporting csv in background - ruby-on-rails

Question

I have made an csv importer and exporter in rails for article model.
It takes the articles and downloads it in the csv format.
It is working fine but I want it to be in a backgrond process.
Can anyone tell how to perform the import and export in background.
Here are my files which I have used-
Article_controller
def index
#articles = Article.all
#articles = Article.includes(:user)
respond_to do |format|
format.html # index.html.erb
format.json { render json: #articles }
format.atom
#articles = Article.order(:name).page params[:page]
format.csv { send_data #articles.to_csv, filename: "#{current_user.email}-#{Date.today}.csv" }
end
end
...
article.rb
def self.import(file,userid)
user = User.find_by(id: userid)
if user
CSV.foreach(file.path, headers: true) do |row|
user.articles.create! row.to_hash
end
end
end
def self.to_csv
attributes = %w{id title content}
CSV.generate(headers: true) do |csv|
csv << attributes
all.each do |article|
csv << article.attributes.values_at(*attributes)
end
end
end

Answer 1

Import:
The import is easier, because the users do not necessarily have to receive feedback after import is done.
As mentioned in the comments you can use ActiveJob with a backend like sidekiq:
You could use a background job in your article.rb:
def self.import(file, userid)
CSVImportJob.perform_later(file.path, userid)
end
class CSVImportJob
def perform(filepath, userid)
user = User.find_by(id: userid)
if user
CSV.foreach(filepath, headers: true) do |row|
user.articles.create! row.to_hash
end
end
end
end
Export:
The export is trickier, because you cannot send a file to user from a background job. You can either poll the results from the browser or send a websocket notification with ActionCable
The background processing would look similar to the import:
def self.export
CSVExportJob.perform_later
end
class CSVExportJob
def perform
attributes = %w{id title content}
CSV.generate(headers: true) do |csv|
csv << attributes
Article.find_each do |article|
csv << article.attributes.values_at(*attributes)
end
end
# Save CSV somewhere and notify its readiness
end
end
Then you would have to create a different route for triggering the CSV creation.
And the ArticleController#index would always return the last exported CSV, that is saved somewhere in the DB or file system.