Class: CoolOptions

Inherits:
Object
  • Object
show all
Defined in:
lib/cooloptions.rb

Overview

For a high-level overview of using CoolOptions, see README.txt.

Usage

:include:samples/literate.rb

Defined Under Namespace

Classes: Error

Constant Summary collapse

VERSION =

:nodoc:

'1.1.1'
NO_DEFAULT =

:nodoc:

Object.new

Instance Attribute Summary collapse

Class Method Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(banner) ⇒ CoolOptions

:nodoc:



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# File 'lib/cooloptions.rb', line 47

def initialize(banner) #:nodoc:
  @parser = OptionParser.new
  @parser.banner = "Usage: #{File.basename($0)} #{banner}"

  @required = []
  @result = {}
  @after = nil
  @used_shorts = {}
end

Instance Attribute Details

#parser ⇒ Object (readonly)

Returns the value of attribute parser.



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# File 'lib/cooloptions.rb', line 45

def parser
  @parser
end

#result ⇒ Object (readonly)

Returns the value of attribute result.



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# File 'lib/cooloptions.rb', line 45

def result
  @result
end

Class Method Details

.out ⇒ Object

:nodoc:



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# File 'lib/cooloptions.rb', line 33

def self.out #:nodoc:
  @out || STDOUT
end

.out=(out) ⇒ Object

:nodoc:



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# File 'lib/cooloptions.rb', line 41

def self.out=(out) #:nodoc:
  @out = out
end

.parse!(banner = "[options]", argv = ARGV) ⇒ Object

Takes an optional banner and the arguments you want to parse (defaults to ARGV) and yields a new CoolOptions to the supplied block. You can then declare your options in the block using the #on method, and do post- processing using #after. When processing is done, an OpenStruct containing the parsed options is returned.



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# File 'lib/cooloptions.rb', line 24

def self.parse!(banner="[options]", argv=ARGV) #:yields: cooloptions
  o = new(banner)
  yield o
  o.parse!(argv)
rescue Error => e
  out.puts e.message
  o.help true
end

Instance Method Details

#after(&after) ⇒ Object

CoolOptions only handles options parsing, and it only does rudimentary option validation. If you want to do more, #after is a convenient place do it, especially since the right thing will just happen if you call #error.



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# File 'lib/cooloptions.rb', line 123

def after(&after)
  @after = after
end

#desc(string) ⇒ Object

Adds additional descriptive text to the help text.



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# File 'lib/cooloptions.rb', line 58

def desc(string)
  string.each_line do |s|
    @parser.separator s.chomp
  end
end

#error(message) ⇒ Object

If you want to throw an option parsing error, just call #error with a message and CoolOptions will bail out and display the help message.

Raises:



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# File 'lib/cooloptions.rb', line 116

def error(message)
  raise Error, message, caller
end

#help(error = false) ⇒ Object

:nodoc:



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# File 'lib/cooloptions.rb', line 127

def help(error=false) #:nodoc:
  out.puts @parser
  exit(error ? 1 : 0)
end

#on(long, description, default = NO_DEFAULT) ⇒ Object

Called on cooloptions within the #parse! block to add options to parse on. Long is the long option itself, description is, well, the description, and default is the default value for the option, if any.



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# File 'lib/cooloptions.rb', line 69

def on(long, description, default=NO_DEFAULT)
  if /^(.)\)(.+)$/ =~ long
    short, long = $1, $2
  elsif /^(.*)\((.)\)(.*)$/ =~ long
    short = $2
    long = $1 + $2 + $3
  end
  short = long[0,1] unless short

  key = long.split(/ /).first.gsub('-', '_').to_sym

  unless long =~ / /
    long = "[no-]#{long}"
  end

  args = []
  args << "-#{short}" unless @used_shorts[short]
  @used_shorts[short] = true
  args.concat(["--#{long}", description])
  if default == NO_DEFAULT
    @required << key
  else
    @result[key] = default
    args << "Default is: #{default}"
  end

  @parser.on(*args){|e| self.result[key] = e}
end

#out ⇒ Object

:nodoc:



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# File 'lib/cooloptions.rb', line 37

def out #:nodoc:
  self.class.out
end

#parse!(argv) ⇒ Object

:nodoc:



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# File 'lib/cooloptions.rb', line 98

def parse!(argv) #:nodoc:
  @parser.on('-h', '--help', "This help info."){help}
  begin
    @parser.parse!(argv)
  rescue OptionParser::ParseError => e
    error e.message.capitalize
  end

  @required.reject!{|e| @result.key?(e)}
  error "Missing required options: #{@required.join(', ')}" unless @required.empty?

  r = OpenStruct.new(@result)
  @after.call(r) if @after
  r
end