Class: Parser

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

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize {|_self| ... } ⇒ Parser

Returns a new instance of Parser.

Yields:

  • (_self)

Yield Parameters:

  • _self (Parser) —

    the object that the method was called on



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# File 'lib/github_downloader/parser.rb', line 4

def initialize
  @options = []
  @used_short = []
  @default_values = nil
  yield self if block_given?
end

Instance Attribute Details

Returns the value of attribute banner.



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# File 'lib/github_downloader/parser.rb', line 2

def banner
  @banner
end

#version ⇒ Object

Returns the value of attribute version.



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# File 'lib/github_downloader/parser.rb', line 2

def version
  @version
end

Instance Method Details

#option(name, desc, settings = {}) ⇒ Object 



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# File 'lib/github_downloader/parser.rb', line 11

def option(name, desc, settings = {})
  @options << [name, desc, settings]
end

#process!(arguments = ARGV) ⇒ Object 



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# File 'lib/github_downloader/parser.rb', line 38

def process!(arguments = ARGV)
  @result = (@default_values || {}).clone # reset or new
  @optionparser ||= OptionParser.new do |p| # prepare only once
    @options.each do |o|
      @used_short << short = o[2][:short] || short_from(o[0])
      @result[o[0]] = o[2][:default] || false # set default
      klass = o[2][:default].class == Fixnum ? Integer : o[2][:default].class

      if [TrueClass, FalseClass, NilClass].include?(klass) # boolean switch
        p.on("-" << short, "--[no-]" << o[0].to_s.gsub("_", "-"), o[1]) { |x| @result[o[0]] = x }
      else # argument with parameter
        p.on("-" << short, "--" << o[0].to_s.gsub("_", "-") << " " << o[2][:default].to_s, klass, o[1]) { |x| @result[o[0]] = x }
      end
    end

    p.banner = @banner unless @banner.nil?
    p.on_tail("-h", "--help", "Show this message") { puts p; exit }
    short = @used_short.include?("v") ? "-V" : "-v"
    p.on_tail(short, "--version", "Print version") { puts @version; exit } unless @version.nil?
    @default_values = @result.clone # save default values to reset @result in subsequent calls
  end

  begin
    @optionparser.parse!(arguments)
  rescue OptionParser::ParseError => e
    puts e.message; exit(1)
  end

  validate(@result) if self.respond_to?("validate")
  @result
end

#short_from(name) ⇒ Object 



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# File 'lib/github_downloader/parser.rb', line 15

def short_from(name)
  name.to_s.chars.each do |c|
    next if @used_short.include?(c) || c == "_"
    return c # returns from short_from method
  end
end

#validate(options) ⇒ Object

remove this method if you want fewer lines of code and don’t need validations



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# File 'lib/github_downloader/parser.rb', line 22

def validate(options) # remove this method if you want fewer lines of code and don't need validations
  options.each_pair do |key, value|
    opt = @options.find_all { |o| o[0] == key }.first
    key = "--" << key.to_s.gsub("_", "-")
    unless opt[2][:value_in_set].nil? || opt[2][:value_in_set].include?(value)
      puts "Parameter for #{key} must be in [" << opt[2][:value_in_set].join(", ") << "]"; exit(1)
    end
    unless opt[2][:value_matches].nil? || opt[2][:value_matches] =~ value
      puts "Parameter for #{key} must match /" << opt[2][:value_matches].source << "/"; exit(1)
    end
    unless opt[2][:value_satisfies].nil? || opt[2][:value_satisfies].call(value)
      puts "Parameter for #{key} must satisfy given conditions (see description)"; exit(1)
    end
  end
end