git.r.bdr.sh - rbdr/lyricli.rb/blob - lib/lyricli/configuration.rb

   1 module Lyricli
   2
   3   # This class handles the configuration of Lyricli
   4   class Configuration
   5
   6     # Defines the paths to the default and user configuration files
   7     def initialize
   8       @config_path = "~/.lyricli.conf"
   9       @defaults_path = "defaults.json"
  10       @config = nil
  11     end
  12
  13     @@instance = Configuration.new
  14
  15     # Ensure this is only called once. Only use the instance class variable
  16     # to access this method, as its constructor is private.
  17     def self.instance
  18       @@instance
  19     end
  20
  21     # Access configuration properties, loads config if needed beforehand.
  22     #
  23     # @param [String] key the configuration key to access
  24     # @return [String, Hash, Array] the value of the configuration key.
  25     def [](key)
  26       load_config unless @config
  27       @config[key]
  28     end
  29
  30     # Assigns a new value to a configuration key, loads config if needed and
  31     # saves it after updating.
  32     #
  33     # @param [String] key the configuration key to set
  34     # @param [Object] value the value for the configuration key, can be any
  35     #                 object as long as it can be converted to JSON
  36     def []=(key, value)
  37       load_config unless @config
  38       @config[key] = value
  39       save_config
  40     end
  41
  42     # Deletes a key from the configuration, loads config if needed and saves
  43     # it after deleting.
  44     #
  45     # @param [String] key the key to delete
  46     def delete(key)
  47       load_config unless @config
  48       @config.delete(key)
  49       save_config
  50     end
  51
  52     private_class_method :new
  53
  54     # Loads the configuration from the user file, attempts to create it from
  55     # defaults if it's not present. sets the `@config` instance variable.
  56     def load_config
  57       path = File.expand_path(@config_path)
  58
  59       if File.exists?(path)
  60         file = File.new(path, "r")
  61         @config = MultiJson.decode(file.read)
  62       else
  63         load_default_config
  64       end
  65     end
  66
  67     # Serializes the `@config` Hash to JSON and saves it to a file.
  68     def save_config
  69       path = File.expand_path(@config_path)
  70       file = File.new(path, "w")
  71       file.print(MultiJson.encode(@config))
  72       file.close
  73     end
  74
  75     private
  76
  77     # Loads the default configuration from a JSON file
  78     def load_default_config
  79       # Load the default
  80       path_root = File.expand_path(File.dirname(__FILE__))
  81       path = File.join(path_root, @defaults_path)
  82
  83       if File.exists?(path)
  84         file = File.new(path, "r")
  85         @config = MultiJson.decode(file.read)
  86       else
  87         @config = {}
  88       end
  89     end
  90   end
  91 end