dotcfg
dotcfg is a simple, intuitive way for your app to store configuration data on the filesystem -- ideally within the user's home directory, presumably in a dotfile. If your config data can be represented by a Hash, then dotcfg can easily serialize and persist that data between runs.
Serialization Formats
dotcfg currently understands JSON and YAML, defaulting to YAML.
Usage
Install
3 options:
git clonegem install-
Bundler
Gemfile
git clone
Clone the repo, then cd dotcfg
Optional, if you use direnv and want to use Nix flakes to load a dev env:
direnv allow
From here, use -I lib with calls to e.g. ruby or irb to make dotcfg
available without having the gem installed. e.g.
$ irb -Ilib -rdotcfg
irb(main):001:0> CFG = DotCfg.new 'example.cfg'
=>
#<DotCfg:0x00007f75d06b83a0
...
irb(main):002:0> CFG[:does_not_exist]
=> nil
irb(main):003:0> CFG['hello'] = 'world'
=> "world"
irb(main):004:0> CFG['hello']
=> "world"
irb(main):005:0>
gem install
gem install dotcfg
Bundler Gemfile
Add to your Gemfile:
gem 'dotcfg', '~> 1.0'Usage
require 'dotcfg'
# if file exists, read and load it; otherwise initialize the file
CFG = DotCfg.new '~/.example'
CFG[:does_not_exist]
# => nil
CFG['hello'] = 'world'
CFG['hello']
# => "world"
puts CFG.pretty
# ---
# hello: world
CFG.serialize
# => "---\nhello: world\n"
CFG.save
# write to ~/.exampleUse JSON
require 'dotcfg'
# if file exists, read and load it; otherwise initialize the file
CFG = DotCfg.new '~/.example', :json
# ...
puts CFG.pretty
# {
# "hello": "world"
# }
CFG.serialize
# => "{\"hello\":\"world\"}"
# ...Details
Symbols and Strings
When JSON consumes symbols, it emits strings. So if you want to use JSON, use strings rather than symbols for your config items. YAML cycles strings and symbols independently, so stick to one or the other.
The Simplest Thing That Could Possibly Work
PROCS = {
json: {
to: proc { |data| data.to_json },
from: proc { |json| JSON.parse json },
pretty: proc { |data| JSON.pretty_generate data },
},
yaml: {
to: proc { |data| data.to_yaml },
from: proc { |yaml| YAML.load yaml },
pretty: proc { |data| data.to_yaml },
},
}