Class: Hammer::Option

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

Overview

Single option/flag definition.

Instance Attribute Summary collapse

Class Method Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(name, **opts) ⇒ Option

Returns a new instance of Option.

Raises:

  • (Hammer::Error) 


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# File 'lib/hammer/option.rb', line 9

def initialize(name, **opts)
  bad = opts.keys - ALLOWED_KEYS
  unless bad.empty?
    raise Hammer::Error,
          "unknown opt parameter(s) for :#{name}: #{bad.join(', ')}. " \
          "allowed: #{ALLOWED_KEYS.join(', ')}"
  end
  @name        = name.to_sym
  @type        = opts[:type] || :string
  @default     = opts[:default]
  @desc        = opts[:desc]
  @aliases     = Array(opts[:alias]).map { |a| Option.normalize_alias(a) }
  @required    = opts[:req] ? true : false
  # Custom usage placeholder, e.g. `placeholder: 't/f'` -> `--log t/f`.
  # Falls back to uppercased name (`--log LOG`) when nil.
  @placeholder = opts[:placeholder]

  # Reserve -h / --help so every command supports them uniformly.
  if RESERVED_FLAGS.include?(switch)
    raise Hammer::Error, "opt :#{name} produces reserved flag #{switch.inspect} (used for help)"
  end
  clash = @aliases.find { |a| RESERVED_FLAGS.include?(a) }
  raise Hammer::Error, "alias #{clash.inspect} is reserved for help" if clash
end

Instance Attribute Details

#aliases ⇒ Object (readonly)

Returns the value of attribute aliases.



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# File 'lib/hammer/option.rb', line 4

def aliases
  @aliases
end

#default ⇒ Object (readonly)

Returns the value of attribute default.



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# File 'lib/hammer/option.rb', line 4

def default
  @default
end

#desc ⇒ Object (readonly)

Returns the value of attribute desc.



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# File 'lib/hammer/option.rb', line 4

def desc
  @desc
end

#name ⇒ Object (readonly)

Returns the value of attribute name.



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# File 'lib/hammer/option.rb', line 4

def name
  @name
end

#placeholder ⇒ Object (readonly)

Returns the value of attribute placeholder.



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# File 'lib/hammer/option.rb', line 4

def placeholder
  @placeholder
end

#required ⇒ Object (readonly)

Returns the value of attribute required.



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# File 'lib/hammer/option.rb', line 4

def required
  @required
end

#type ⇒ Object (readonly)

Returns the value of attribute type.



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# File 'lib/hammer/option.rb', line 4

def type
  @type
end

Class Method Details

.normalize_alias(value) ⇒ Object

‘:p` -> `-p`, `:dry_run` -> `–dry-run`. Strings starting with `-` pass through untouched.



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# File 'lib/hammer/option.rb', line 36

def self.normalize_alias(value)
  s = value.to_s
  return s if s.start_with?('-')
  s.length == 1 ? "-#{s}" : "--#{s.tr('_', '-')}"
end

Instance Method Details

#annotation ⇒ Object

“(default: dev)” or “(required)”



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# File 'lib/hammer/option.rb', line 74

def annotation
  return '(required)' if required
  return '' if default.nil?
  "(default: #{default.inspect})"
end

#boolean? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/hammer/option.rb', line 42

def boolean?
  type == :boolean
end

#cast(value) ⇒ Object 



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# File 'lib/hammer/option.rb', line 54

def cast(value)
  case type
  when :boolean then !!value && value != 'false' && value != '0'
  when :integer then Integer(value)
  when :float   then Float(value)
  when :array   then value.is_a?(Array) ? value : value.to_s.split(',')
  else value.to_s
  end
end

#negation ⇒ Object 



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# File 'lib/hammer/option.rb', line 50

def negation
  "--no-#{name.to_s.tr('_', '-')}"
end

#switch ⇒ Object 



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# File 'lib/hammer/option.rb', line 46

def switch
  "--#{name.to_s.tr('_', '-')}"
end

#usage ⇒ Object 



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# File 'lib/hammer/option.rb', line 64

def usage
  flag = switch
  flag += " #{placeholder || name.to_s.upcase}" unless boolean?
  line = aliases.empty? ? flag : "#{aliases.join(', ')}, #{flag}"
  suffix = annotation
  line = "#{line.ljust(28)} #{desc}" if desc
  suffix.empty? ? line : "#{line} #{suffix}"
end