Kvcsv

A lightweight Ruby gem for managing application settings from CSV files. Kvcsv provides a simple, read-only interface for loading configuration from one or more CSV files with automatic type conversion for boolean and nil values.

• Load settings from one or more CSV files
• Automatic type conversion (true/false/nil)
• Simple key-based access with symbol keys
• Support for default values via fetch
• Enumerable interface (map, select, etc.)
• Later files override earlier ones for easy environment-specific configuration

Install the gem and add to the application's Gemfile by executing:

bundle add kvcsv

If bundler is not being used to manage dependencies, install the gem by executing:

gem install kvcsv

Create CSV files with two columns: key and value:

key,value
database_host,localhost
database_port,5432
debug,true
cache_enabled,false
api_key,sk-1234567890
timeout,30
environment,production

require 'kvcsv'

# Load from a single file
settings = KVCSV::Settings.new("config/app.csv")

# Access settings
database_host = settings[:database_host]  # => "localhost"
debug_mode = settings[:debug]             # => true (automatically converted)
missing_key = settings[:missing_key]      # => nil

# Use fetch with defaults
port = settings.fetch(:port, 3000)        # => 3000 (default value)

Later files override values from earlier files:

# config/defaults.csv has debug=false
# config/production.csv has debug=true
settings = KVCSV::Settings.new(
  "config/defaults.csv",
  "config/production.csv"
)

settings[:debug]  # => true (from production.csv)

The following values are automatically converted:

• True values: t, 1, true, yes, y (case-insensitive)
• False values: f, 0, false, no, n (case-insensitive)
• Nil values: nil, null, na, n/a (case-insensitive), or empty values

key,value
feature_enabled,true
verbose,yes
disabled,0
optional_field,nil

settings = KVCSV::Settings.new("config.csv")
settings[:feature_enabled]  # => true
settings[:verbose]          # => true
settings[:disabled]         # => false
settings[:optional_field]   # => nil

Settings objects support enumerable methods:

# Map over settings
urls = settings.map { |key, value| value if key.to_s.end_with?("_url") }.compact

# Select specific settings
database_settings = settings.select { |key, _| key.to_s.start_with?("database_") }

# Check for existence
settings.fetch(:required_key)  # Raises KeyError if not found

After checking out the repo, run bin/setup to install dependencies. You can also run bin/console for an interactive prompt that will allow you to experiment.

To install this gem onto your local machine, run bundle exec rake install. To release a new version, update the version number in version.rb, and then run bundle exec rake release, which will create a git tag for the version, push git commits and the created tag, and push the .gem file to rubygems.org.

Bug reports and pull requests are welcome on GitHub at https://github.com/aguynamedryan/kvcsv.