Export Rails ActiveRecords to CSV¶ ↑

For a recent “enterprisey” project I’m working on, we had to offer a variety of CSV exports for many of the models in our system. Ruby’s FasterCSV library is great for raw parsing and generation of CSV data, so I used that as the basis for a quick and dirty system to easily provide customizable exports.

Features¶ ↑

• Transform an array of exportable records into a whole CSV file. (By default, FasterCSV transforms arrays into a single CSV row.)

• Export a whole table my calling .to_csv on the ActiveRecord subclass.

• By default, export all of an ActiveRecord’s columns except for created_at and updated_at.

• Allow simple customization of exportable columns by overriding the export_columns method in your ActiveRecord class.

• Allow multiple CSV formats by conditionally branching inside the export_columns method depending on the format parameter.

• Allow complete customization of the export by overriding the to_row method. (I haven’t actually needed this much customization yet.)

Examples¶ ↑

The simplest example:

Address.to_csv

Customizing the columns included in the CSV:

class Address < ActiveRecord::Base
  def export_columns(format = nil)
    %w[city state postal_code]
  end
end

Multiple output formats:

class Address < ActiveRecord::Base
  def export_columns(format = nil)
    case format
    when :local
      %w[street1 street2 city state postal_code]
    else
      %w[city state postal_code]
    end
  end
end

Installation¶ ↑

Install the plugin in your Rails project like so…

$ script/plugin install git://github.com/scottbarr/to_csv.git

Original Author¶ ↑

This code for this plugin was written by Bryan Helmkamp. The original post can be found at www.brynary.com/2007/4/28/export-activerecords-to-csv

Bryan informed me that there is a later version of this code at www.mobilecommons.com/developers/open-source/exportable/ but it did not work for me. I’ll try to see what the problem is when I have a chance.