Class: Executable::Help

Inherits:
Object
  • Object
show all
Defined in:
lib/executable/help.rb

Overview

Encpsulates command help for defining and displaying well formated help output in plain text, markdown or via manpages if found.

TODO: Currently doesn’t hande aliases/shortcuts well and simply lists them as separate entries.

Creating text help in the fly is fine for personal projects, but for production app, ideally you want to have man pages. You can use the #markdown method to generate ‘.ronn` files and use the ronn tool to build manpages for your project. There is also the binman and md2man projects which can be used similarly.

Defined Under Namespace

Classes: Option

Instance Attribute Summary collapse

Class Method Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(cli_class) ⇒ Help

Setup new help object.



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# File 'lib/executable/help.rb', line 34

def initialize(cli_class)
  @cli_class = cli_class

  @name       = nil
  @usage      = nil
  @decription = nil
  @copying    = nil
  @see_also   = nil

  @options = {}
  @subcmds = {}
end

Instance Attribute Details

#cli_class ⇒ Object (readonly)

The Executable subclass to which this help applies.



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# File 'lib/executable/help.rb', line 53

def cli_class
  @cli_class
end

Class Method Details

.section(name, &default) ⇒ Object 



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# File 'lib/executable/help.rb', line 20

def self.section(name, &default)
  define_method("default_#{name}", &default)
  class_eval %{
    def #{name}(text=nil)
      @#{name} = text.to_s unless text.nil?
      @#{name} ||= default_#{name}
    end
    def #{name}=(text)
      @#{name} = text.to_s
    end
  }
end

Instance Method Details

#call_method ⇒ Object (private) 



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# File 'lib/executable/help.rb', line 338

def call_method
  @call_method ||= method_list.find{ |m| m.name == :call }
end

#copyright(text = nil) ⇒ Object

Get or set copyright text.



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# File 'lib/executable/help.rb', line 92

section(:copyright) do
  'Copyright (c) ' + Time.now.strftime('%Y')
end

#description(text = nil) ⇒ Object

Get or set command description.



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# File 'lib/executable/help.rb', line 83

section(:description) do
  nil
end

#inspect ⇒ Object 



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# File 'lib/executable/help.rb', line 48

alias_method :inspect, :to_s

#lookup(glob, dir) ⇒ Object (private) 



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# File 'lib/executable/help.rb', line 363

def lookup(glob, dir)
  dir  = File.expand_path(dir)
  root = '/'
  home = File.expand_path('~')
  list = []

  while dir != home && dir != root
    list.concat(Dir.glob(File.join(dir, glob)))
    break unless list.empty?
    dir = File.dirname(dir)
  end

  list.first
end

#manpage(dir = nil) ⇒ Object

Get man-page if there is one.



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# File 'lib/executable/help.rb', line 144

def manpage(dir=nil)
  @manpage ||= (
    man = []
    dir = nil

    if dir
      raise unless File.directory?(dir)
    end

    if !dir && call_method
      file, line = call_method.source_location
      dir = File.dirname(file)
    end

    man_name = name.gsub(/\s+/, '-') + '.1'

    if dir
      glob = "man/{man1/,}#{man_name}"
      lookup(glob, dir)
    else
      nil
    end
  )
end

#markdown ⇒ Object Also known as: md

Generate a RONN-style Markdown.



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# File 'lib/executable/help.rb', line 218

def markdown
  commands = text_subcommands
  options  = text_options
  dashname = name.sub(/\s+/, '-')

  s = []

  h = "#{dashname}(1) - #{text_description}"
  s << h + "\n" + ("=" * h.size)

  s << "## SYNOPSIS"
  s << "`" + name + "` [options...] [subcommand]"

  s << "## DESCRIPTION"
  s << text_description

  if !commands.empty?
    s << "## COMMANDS"
    s << commands.map{ |cmd, desc|
      "  * `%s:`\n    %s" % [cmd, desc] 
    }.join("\n")
  end

  if !options.empty?
    s << "## OPTIONS"
    s << options.map{ |max, opt|
      "  * `#{opt.mark}%s`:\n    %s" % [opt.usage, opt.description]
    }.join("\n\n")
  end

  if copyright && !copyright.empty?
    s << "## COPYRIGHT"
    s << copyright
  end

  if see_also && !see_also.empty?
    s << "## SEE ALSO"
    s << see_also
  end

  s.compact.join("\n\n")
end

#method_list ⇒ Object (private)

Produce a list relavent methods.



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# File 'lib/executable/help.rb', line 345

def method_list
  list      = []
  methods   = []
  stop_at   = cli_class.ancestors.index(Executable::Command) ||
              cli_class.ancestors.index(Executable) ||
              -1
  ancestors = cli_class.ancestors[0...stop_at]
  ancestors.reverse_each do |a|
    a.instance_methods(false).each do |m|
      list << cli_class.instance_method(m)
    end
  end
  list
end

#name(text = nil) ⇒ Object

TODO:

Should this instead default to ‘File.basename($0)` ?

Get or set command name.

By default the name is assumed to be the class name, substituting dashes for double colons.



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# File 'lib/executable/help.rb', line 65

section(:name) do
  cli_class.usage_name
end

#option(name, description) ⇒ Object

Set description of an option.



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# File 'lib/executable/help.rb', line 108

def option(name, description)
  @options[name.to_s] = description
end

#option_list ⇒ Object 



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# File 'lib/executable/help.rb', line 324

def option_list
  @option_list ||= (
    method_list.map do |meth|
      case meth.name
      when /^(.*?)[\!\=]$/
        Option.new(meth)
      end
    end.compact.sort
  )
end

#see_also(text = nil) ⇒ Object

Get or set “see also” text.



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# File 'lib/executable/help.rb', line 101

section(:see_also) do
  nil
end

#show_help(hint = nil) ⇒ Object Also known as: show

TODO:

man-pages will probably fail on Windows.

Show help.



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# File 'lib/executable/help.rb', line 124

def show_help(hint=nil)
  if file = manpage(hint)
    show_manpage(file)
  else
    puts self
  end
end

#show_manpage(file) ⇒ Object 



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# File 'lib/executable/help.rb', line 136

def show_manpage(file)
  #exec "man #{file}"
  system "man #{file}"
end

#subcommand(name, description) ⇒ Object

Set desciption of a subcommand.



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# File 'lib/executable/help.rb', line 115

def subcommand(name, description)
  @subcmds[name.to_s] = description
end

#text ⇒ Object Also known as: txt

Generate plain text output.



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# File 'lib/executable/help.rb', line 185

def text
  commands = text_subcommands
  options  = text_options

  s = []

  s << usage
  s << text_description

  if !commands.empty?
    s << "COMMANDS\n" + commands.map{ |cmd, desc|
      "  %-17s %s" % [cmd, desc] 
    }.join("\n")
  end

  if !options.empty?
    s << "OPTIONS\n" + options.map{ |max, opt|
      "  %2s%-#{max}s %s" % [opt.mark, opt.usage, opt.description]
    }.join("\n")
  end

  s << copyright
  s << see_also

  s.compact.join("\n\n")
end

#text_description ⇒ String, NilClass

Description of command in printable form. But will return nil if there is no description.

Returns:

  • (String, NilClass) —

    command description



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# File 'lib/executable/help.rb', line 270

def text_description
  return description if description
  #return Source.get_above_comment(@file, @line) if @file

  call_method ? call_method.comment : nil
end

#text_options ⇒ Array<Fixnum, Options>

List of options coverted to a printable string. But will return nil if there are no options.

Returns:

  • (Array<Fixnum, Options>) —

    option list for output



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# File 'lib/executable/help.rb', line 297

def text_options
  option_list.each do |opt|
    if @options.key?(opt.name)
      opt.description = @options[opt.name]
    end
  end    

  max = option_list.map{ |opt| opt.usage.size }.max.to_i + 2

  option_list.map do |opt|
    [max, opt]
  end
end

#text_subcommands ⇒ String, NilClass

List of subcommands converted to a printable string. But will return nil if there are no subcommands.

Returns:

  • (String, NilClass) —

    subcommand list text



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# File 'lib/executable/help.rb', line 283

def text_subcommands
  commands = @cli_class.subcommands
  commands.map do |cmd, klass|
    desc = klass.help.text_description.to_s.split("\n").first
    [cmd, desc]
  end
end

#to_s(format = nil) ⇒ Object

Render help text to a given format. If no format it given then renders to plain text.



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# File 'lib/executable/help.rb', line 173

def to_s(format=nil)
  case format
  when :markdown, :md
    markdown
  else
    text
  end
end

#usage(text = nil) ⇒ Object

Get or set command usage string.



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# File 'lib/executable/help.rb', line 74

section(:usage) do
  "Usage: " + name + ' [options...] [subcommand]'
end