csv-mapper¶ ↑

CsvMapper is a small library intended to simplify the common steps involved with importing CSV files to a usable form in Ruby. CsvMapper is compatible with recent 1.8 versions of Ruby as well as Ruby 1.9+

The following example will import a CSV file to an Array of Struct instances.

First Name,Last Name,Age
John,Doe,27
Jane,Doe,26
Bat,Man,52
...etc...

results = CsvMapper.import('/path/to/file.csv') do
  start_at_row 1
  [first_name, last_name, age]
end

results.first.first_name  # John
results.first.last_name   # Doe
results.first.age         # 27

results = CsvMapper.import('/path/to/file.csv') do
  read_attributes_from_file
end

results.first.first_name  # John
results.first.last_name   # Doe
results.first.age         # 27

Columns which aren’t mentioned won’t appear in the results.

# Don't mention first name
results = CsvMapper.import('/path/to/file_with_header_row.csv') do
  named_columns

  surname('last_name')
  age
end

results.first.surname     # Doe
results.first.age         # 27
results.first.first_name  # nil
results.first.last_name   # nil

Although CsvMapper has no dependency on ActiveRecord; it’s easy to import a CSV file to ActiveRecord models and save them.

# Define an ActiveRecord model
class Person < ActiveRecord::Base; end

results = CsvMapper.import('/path/to/file.csv') do
  map_to Person # Map to the Person ActiveRecord class (defined above) instead of the default Struct.
  after_row lambda{|row, person| person.save }  # Call this lambda and save each record after it's parsed.

  start_at_row 1
  [first_name, last_name, age]
end

See CsvMapper for a more detailed description

FasterCSV on pre 1.9 versions of Ruby

• sudo gem install csv-mapper

• Fork the project.

• Make your feature addition or bug fix.

• Add tests for it. This is important so I don’t break it in a future version unintentionally.

• Commit, do not mess with rakefile, version, or history. (if you want to have your own version, that is fine but bump version in a commit by itself I can ignore when I pull)

• Send me a pull request. Bonus points for topic branches.

Copyright © 2009 Luke Pillow. See LICENSE for details.