`class UsageFormatter`

Formats and prints usage information to a terminal.

Dispatches on the type of each output object to apply custom formatting rules.

Definitions

`def self.print(rows, output)`

Print usage information to the output.

Signature

parameter　rows　Rows: The rows to format and print.
parameter　output　IO: The output stream to print to.
yields　{|formatter| ...}: Optional block to customize the formatter.

Implementation

def self.print(rows, output)
	formatter = self.new(output)
	
	yield formatter if block_given?
	
	formatter.print(rows)
end

`def print(rows, first: true)`

Print the formatted usage output.

Implementation

def print(rows, first: true)
	map(rows, first: first)
end

`def initialize(output)`

Initialize a new usage formatter.

Signature

parameter　rows　Rows: The rows to format.
parameter　output　IO: The output stream to print to.

Implementation

def initialize(output)
	@output = output
	@width = 80
	
	@terminal = Console::Terminal.for(@output)
	@terminal[:header] = @terminal.style(nil, nil, :bright)
	@terminal[:description] = @terminal.style(:blue)
	@terminal[:error] = @terminal.style(:red)
end

`def map(object, *arguments, first: true)`

Format and print the given object according to its type.

Signature

parameter　object　Object: The object to format (a class Samovar::Output::Rows, class Samovar::Output::Row, class Samovar::Output::Header, or error).
parameter　arguments　Array: Extra context passed through to nested rows (the containing class Samovar::Output::Rows).

Implementation

def map(object, *arguments, first: true)
	case object
	when InvalidInputError
		# This is a little hack which avoids printing out "--help" if it was part of an incomplete parse. In the future I'd prefer if this was handled explicitly.
		@terminal.puts("#{object.message} in:", style: :error) unless object.help?
	when MissingValueError
		@terminal.puts("#{object.message} in:", style: :error)
	when Header
		header, rows = object, arguments.first
		
		if first
			first = false
		else
			@terminal.puts
		end
		
		command_line = header.object.command_line(header.name)
		@terminal.puts "#{rows.indentation}#{command_line}", style: :header
		
		if description = header.object.description
			@terminal.puts "#{rows.indentation}\t#{description}", style: :description
			@terminal.puts
		end
	when Row
		row, rows = object, arguments.first
		@terminal.puts "#{rows.indentation}#{row.align(rows.columns)}"
	when Rows
		object.each do |row, rows|
			first = map(row, rows, first: first)
		end
	else
		raise ArgumentError, "Unable to format #{object.class}!"
	end
	
	return first
end