Class: OptSimple::Parameter

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

Overview

The base class for command line parameter objects from which Flag, Option and Argument are derived. Users will probably only use the an ‘error method’ and the ‘set_opt’ utility funciton.

Direct Known Subclasses

Flag, Option

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(switches, help = "", &block) ⇒ Parameter

‘switches’ can be a String or an Array of Strings, and specifies the switches expected on the CL. ‘help’ provides a description of the parameter and an optional block can do parameter validation/transformation.



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# File 'lib/opt_simple.rb', line 334

def initialize(switches,help="",&block)
  self.switches = switches
  @help = help
  @block = block
  @param_options = OptSimple::Result.new
  @param_options.add_alias(self.names)
end

Instance Attribute Details

#block ⇒ Object (readonly)

Returns the value of attribute block.



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# File 'lib/opt_simple.rb', line 329

def block
  @block
end

#metavar ⇒ Object (readonly)

Returns the value of attribute metavar.



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# File 'lib/opt_simple.rb', line 329

def metavar
  @metavar
end

#param_options ⇒ Object (readonly)

Returns the value of attribute param_options.



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# File 'lib/opt_simple.rb', line 329

def param_options
  @param_options
end

#switches ⇒ Object

Returns the value of attribute switches.



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# File 'lib/opt_simple.rb', line 329

def switches
  @switches
end

Instance Method Details

#error(string) ⇒ Object

A shortcut for raising an OptSimple::Error exception



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# File 'lib/opt_simple.rb', line 383

def error(string)
  raise OptSimple::Error.new string
end

#help_str(switch_len) ⇒ Object

a single line that will be put in the overall usage string



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# File 'lib/opt_simple.rb', line 378

def help_str(switch_len)
  "    %-#{switch_len}s"  % self.switch_str + " \t#{@help}"
end

#mandatory? ⇒ Boolean

is it mandatory to see this parameter on the command line? Returns false unless overidden.

Returns:

  • (Boolean) 


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# File 'lib/opt_simple.rb', line 395

def mandatory?; false; end

#names ⇒ Object

returns a list of the switches without the leading ‘-’s



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# File 'lib/opt_simple.rb', line 348

def names
  names = []
  switches.each do  |s| 
	st = s.sub(/^-+/,'')
	names << st << st.to_sym 
	if st.include?('-')
	  st2 = st.gsub('-','_') 
	  names << st2 << st2.to_sym
	end
  end
  names 
end

#set_opt(val) ⇒ Object

A utility function that sets all the names to the specified value in the param_options data structure.



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# File 'lib/opt_simple.rb', line 389

def set_opt val
  # all the other values are aliased, so we only need to set the first
  @param_options[names.first] = val
end

#switch_len ⇒ Object

:nodoc:



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# File 'lib/opt_simple.rb', line 361

def switch_len #:nodoc:
  @switches.join(', ').length 
end

#switch_str ⇒ Object

:nodoc:



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# File 'lib/opt_simple.rb', line 365

def switch_str #:nodoc:
  short_parms = @switches.find_all {|st| st.start_with?('-') and st.length == 2 and st[1] != '-'} 
  long_parms = @switches.find_all {|st| st.start_with?('--') or (st.start_with?('-') and st.length > 2)} 
  other_parms = @switches.find_all {|st| not st.start_with?('-')}
  
  sh_str = short_parms.empty? ?  " " * 4 : short_parms.first
  long_str = long_parms.join(', ') + other_parms.join(', ')
  sh_str << ', ' unless sh_str =~/^\s+$/ or long_str.empty?

  sh_str + long_str
end