lib/common/configuration.rb

   1 require 'yaml'
   2
   3 # A configuration object that knows how to read options out of a file
   4 # in <tt>$XDG_CONFIG_HOME/mailshears/mailshears.conf.yml</tt>. The
   5 # configuration options can be accessed via methods even though the
   6 # internal representation is a hash.
   7 #
   8 # === Examples
   9 #
  10 #   >> cfg = Configuration.new()
  11 #   >> cfg.i_mean_business()
  12 #   => true
  13 #
  14 class Configuration
  15
  16   # The hash structure in which we store our configuration options
  17   # internally.
  18   @dict = {}
  19
  20   # Initialize a {Configuration} object with the config file at *path*.
  21   #
  22   # @param path [String] the path to the configuration file to
  23   #   load. We check for a file named "mailshears.conf.yml" in the
  24   #   user's XDG configuration directory by default.
  25   #
  26   def initialize(path = nil)
  27     if path.nil? then
  28         # The default path to the user's configuration file.
  29       path = ENV['HOME'] + '/.config'
  30       if ENV.has_key?('XDG_CONFIG_HOME') then
  31         path = ENV['XDG_CONFIG_HOME']
  32       end
  33       path += '/mailshears/mailshears.conf.yml'
  34     end
  35
  36     cfg = default_configuration()
  37
  38     # Now, load the user configuration which will override the
  39     # variables defined above.
  40     begin
  41       user_config = YAML.load(File.open(path))
  42
  43       # Write our own update() method for Ruby 1.8.
  44       user_config.each do |key, value|
  45         cfg[key] = value
  46       end
  47     rescue Errno::ENOENT
  48       # If the user config file doesn't exist, whatever.
  49     end
  50
  51     # Convert all of the keys to symbols.
  52     cfg = cfg.inject({}){|memo,(k,v)| memo[k.to_sym] = v; memo}
  53
  54     @dict = cfg
  55   end
  56
  57
  58   # Replace all missing method calls with hash lookups. This lets us
  59   # retrieve the values in our option hash by using methods named
  60   # after the associated keys.
  61   #
  62   # @param sym [Symbol] the method that was called.
  63   #
  64   # @return [Object] the config file value associated with *sym*.
  65   #
  66   def method_missing(sym, *args)
  67     return @dict[sym]
  68   end
  69
  70
  71   private;
  72
  73
  74   # A default config hash.
  75   #
  76   # @return [Hash] sensible default configuration values.
  77   #
  78   def default_configuration()
  79     d = {}
  80
  81     d['i_mean_business'] = false
  82     d['plugins'] = ['postfixadmin']
  83
  84     d['davical_dbhost'] = 'localhost'
  85     d['davical_dbport'] = 5432
  86     d['davical_dbopts'] = ''
  87     d['davical_dbuser'] = 'postgres'
  88     d['davical_dbpass'] = ''
  89     d['davical_dbname'] = 'davical'
  90
  91     d['dovecot_mail_root'] = '/tmp/mailshears-test'
  92
  93     d['postfixadmin_dbhost'] = 'localhost'
  94     d['postfixadmin_dbport'] = 5432
  95     d['postfixadmin_dbopts'] = ''
  96     d['postfixadmin_dbuser'] = 'postgres'
  97     d['postfixadmin_dbpass'] = ''
  98     d['postfixadmin_dbname'] = 'postfixadmin'
  99
 100     d['roundcube_dbhost'] = 'localhost'
 101     d['roundcube_dbport'] = 5432
 102     d['roundcube_dbopts'] = ''
 103     d['roundcube_dbuser'] = 'postgres'
 104     d['roundcube_dbpass'] = ''
 105     d['roundcube_dbname'] = 'roundcube'
 106
 107     return d
 108   end
 109
 110 end