Class: Samovar::Option

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

Overview

Represents a single command-line option.

An option is a flag-based argument that can have various forms (short, long, with or without values).

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(flags, description, key: nil, default: nil, value: nil, type: nil, required: false, completions: nil, &block) ⇒ Option

Initialize a new option.



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# File 'lib/samovar/option.rb', line 27

def initialize(flags, description, key: nil, default: nil, value: nil, type: nil, required: false, completions: nil, &block)
	@flags = Flags.new(flags)
	@description = description
	
	if key
		@key = key
	else
		@key = @flags.first.key
	end
	
	@default = default
	
	# If the value is given, it overrides the user specified input.
	@value = value
	@value ||= true if @flags.boolean?
	
	@type = type
	@required = required
	@completions = completions
	@block = block
end

Instance Attribute Details

#block ⇒ Object (readonly)

An optional block to transform the parsed value.



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# File 'lib/samovar/option.rb', line 105

def block
  @block
end

#completions ⇒ Object (readonly)

Completions for option values.



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# File 'lib/samovar/option.rb', line 100

def completions
  @completions
end

#description ⇒ Object (readonly)

A description of the option for help output.



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# File 'lib/samovar/option.rb', line 57

def description
  @description
end

#flags ⇒ Object

The flags for this option.



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# File 'lib/samovar/option.rb', line 52

def flags
  @flags
end

#key ⇒ Object

The key to use for storing the value.



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# File 'lib/samovar/option.rb', line 62

def key
  @key
end

#required ⇒ Object

Whether the option is required.



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# File 'lib/samovar/option.rb', line 95

def required
  @required
end

#type ⇒ Object (readonly)

The type to coerce the value to.



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# File 'lib/samovar/option.rb', line 90

def type
  @type
end

#value ⇒ Object

A fixed value to use regardless of user input.



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# File 'lib/samovar/option.rb', line 85

def value
  @value
end

Instance Method Details

#coerce(result) ⇒ Object

Coerce and transform the result.



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# File 'lib/samovar/option.rb', line 165

def coerce(result)
	if @type
		result = coerce_type(result)
	end
	
	if @block
		result = @block.call(result)
	end
	
	return result
end

#coerce_type(result) ⇒ Object

Coerce the result to the specified type.



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# File 'lib/samovar/option.rb', line 147

def coerce_type(result)
	if @type == Integer
		Integer(result)
	elsif @type == Float
		Float(result)
	elsif @type == Symbol
		result.to_sym
	elsif @type.respond_to? :call
		@type.call(result)
	elsif @type.respond_to? :new
		@type.new(result)
	end
end

#default ⇒ Object

The default value if the option is not provided.



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# File 'lib/samovar/option.rb', line 67

def default
	if @default.respond_to?(:call)
		@default.call
	else
		@default
	end
end

#default? ⇒ Boolean

Whether this option has a default value.

Returns:

  • (Boolean) 


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# File 'lib/samovar/option.rb', line 78

def default?
	!@default.nil?
end

#flag_for(token) ⇒ Object

Find the flag that matches the given token.



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# File 'lib/samovar/option.rb', line 111

def flag_for(token)
	@flags.flag_for(token)
end

#parse(input, parent = nil, default = nil) ⇒ Object

Parse this option from the input.



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# File 'lib/samovar/option.rb', line 183

def parse(input, parent = nil, default = nil)
	result = @flags.parse(input)
	
	if result != nil
		@value.nil? ? coerce(result) : @value
	end
end

#suggestions(context) ⇒ Object

Complete values for this option.



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# File 'lib/samovar/option.rb', line 126

def suggestions(context)
	suggestions = []
	context = context.with_row(self)
	
	if default?
		suggestion = Completion::Provider.new(context, [default]).suggestions.first
		
		suggestions << suggestion if suggestion
	end
	
	Completion::Provider.new(context, @completions).suggestions.each do |suggestion|
		suggestions << suggestion unless suggestions.any?{|existing| existing.value == suggestion.value}
	end
	
	Completion::Result.new(suggestions)
end

#to_a ⇒ Object

Generate an array representation for usage output.



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# File 'lib/samovar/option.rb', line 201

def to_a
	if default?
		[@flags, @description, "(default: #{default})"]
	elsif @required
		[@flags, @description, "(required)"]
	else
		[@flags, @description]
	end
end

#to_s ⇒ Object

Generate a string representation for usage output.



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# File 'lib/samovar/option.rb', line 194

def to_s
	@flags
end

#value? ⇒ Boolean

Whether this option consumes a value after the flag.

Returns:

  • (Boolean) 


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# File 'lib/samovar/option.rb', line 118

def value?
	@flags.any?{|flag| !flag.boolean?}
end