CSV Export (Rails)

gistfile1.txt

# Good solution for exporting to CSV in rails.
# Source: https://www.codementor.io/victorhazbun/export-records-to-csv-files-ruby-on-rails-vda8323q0

class UsersController < ApplicationController
  def index
    @users = User.all

    respond_to do |format|
      format.html
      format.csv { send_data @users.to_csv, filename: "users-#{Date.today}.csv" }
    end
  end
end

class User < ActiveRecord::Base
  def self.to_csv
    attributes = %w{id email name}

    CSV.generate(headers: true) do |csv|
      csv << attributes

      all.each do |user|
        csv << attributes.map{ |attr| user.send(attr) }
      end
    end
  end
end

<%= link_to 'Export CSV', user_path(format: :csv) %>

Just an FYI this needs tweaked to support only making a CSV of a subset of the model.

ActionController::Renderers.add :csv do |csv, options|
    self.content_type ||= Mime::CSV
    self.response_body  = csv.respond_to?(:to_csv) ? csv.to_csv : csv
end

Would allow for format.csv { render csv: @communications }