Class: Samovar::Nested

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

Overview

Represents nested sub-commands in a command.

A ‘Nested` parser allows you to define multiple sub-commands that can be invoked from the parent command.

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(key, commands, default: nil, required: false) ⇒ Nested

Initialize a new nested command parser.



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# File 'lib/samovar/nested.rb', line 17

def initialize(key, commands, default: nil, required: false)
  @key = key
  @commands = commands
  
  # This is the default name [of a command], not the default command:
  @default = default
  
  @required = required
end

Instance Attribute Details

#commands ⇒ Object

A mapping of command names to command classes.



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# File 'lib/samovar/nested.rb', line 35

def commands
  @commands
end

#default ⇒ Object (readonly)

The default command name if none is provided.



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# File 'lib/samovar/nested.rb', line 40

def default
  @default
end

#key ⇒ Object

The name of the attribute to store the selected command in.



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# File 'lib/samovar/nested.rb', line 30

def key
  @key
end

#required ⇒ Object

Whether a command is required.



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# File 'lib/samovar/nested.rb', line 45

def required
  @required
end

Instance Method Details

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

Parse a nested command from the input.



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# File 'lib/samovar/nested.rb', line 83

def parse(input, parent = nil, default = nil)
  if command = @commands[input.first]
    name = input.shift
    
    # puts "Instantiating #{command} with #{input}"
    command.new(input, name: name, parent: parent)
  elsif default
    return default
  elsif @default
    @commands[@default].new(input, name: @default, parent: parent)
  elsif @required
    raise MissingValueError.new(parent, @key)
  end
end

#to_a ⇒ Object

Generate an array representation for usage output.



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

def to_a
  usage = [self.to_s]
  
  if @commands.size == 0
    usage << "No commands available."
  elsif @commands.size == 1
    usage << "Only #{@commands.first}."
  else
    usage << "One of: #{@commands.keys.join(', ')}."
  end
  
  if @default
    usage << "(default: #{@default})"
  elsif @required
    usage << "(required)"
  end
  
  return usage
end

#to_s ⇒ Object

Generate a string representation for usage output.



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# File 'lib/samovar/nested.rb', line 50

def to_s
  "<#{@key}>"
end

#usage(rows) ⇒ Object

Generate usage information for this nested command.



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# File 'lib/samovar/nested.rb', line 101

def usage(rows)
  rows << self
  
  @commands.each do |key, klass|
    klass.usage(rows, key)
  end
end