Class: UserChoices::EnvironmentSource

Inherits:
AbstractSource show all
Defined in:
lib/user-choices/sources.rb

Overview

Describe the environment as a source of choices.

Instance Attribute Summary

Attributes inherited from AbstractSource

#external_names

Instance Method Summary collapse

Methods inherited from AbstractSource

#adjust, #apply, #each_conversion, #initialize

Constructor Details

This class inherits a constructor from UserChoices::AbstractSource

Instance Method Details

#fill ⇒ Object

:nodoc:



104
105
106
107
108
 
# File 'lib/user-choices/sources.rb', line 104

def fill    # :nodoc:
  @external_names.each { | key, env_var |
    self[key] = ENV[env_var] if ENV.has_key?(env_var)
  }
end

#mapping(map) ⇒ Object

Some environment variables have names you don’t like. For example, $HOME might be annoying because of the uppercase. Also, if most of your program’s environment variables have some prefix (see with_prefix) but you also want to use $HOME, you need a way to do that. You can satisfy both desires with

EnvironmentSource.new.with_prefix("my_").mapping(:home => "HOME")



139
140
141
142
 
# File 'lib/user-choices/sources.rb', line 139

def mapping(map)
  @external_names.merge!(map)
  self
end

#source ⇒ Object

:nodoc:



145
146
147
 
# File 'lib/user-choices/sources.rb', line 145

def source    # :nodoc:
  "the environment"
end

#with_prefix(prefix) ⇒ Object

Environment variables beginning with prefix (a string) are considered to be user choices relevant to this script. Everything after the prefix names a choice (that is, a symbol). Dashes are converted to underscores. Examples:

  • Environment variable prefix-my-choice with prefix "prefix-" is choice <tt>:my_choice.

  • Environment variable PREFIX_FOO with prefix "PREFIX_" is choice <tt>:FOO

If you want an array of strings, separate the values by commas: ENV_VAR=a,b,c There’s currently no way to escape a comma and no cleverness about quotes or whitespace.



122
123
124
125
126
127
128
129
130
 
# File 'lib/user-choices/sources.rb', line 122

def with_prefix(prefix)
  matches = ENV.collect do | env_var, ignored_value |
    if /^#{prefix}(.+)/ =~ env_var
      [$1.to_inputable_sym, env_var]
    end
  end
  @external_names.merge!(Hash[*matches.compact.flatten])
  self
end