lib/html2haml/exec.rb
require 'optparse'
require 'fileutils'
require 'rbconfig'
module Html2haml
# This module handles the Html2haml executable.
module Exec
# An abstract class that encapsulates the executable code for the Html2haml executable.
# It's split into a base class and a subclass for historic reasons: this previously
# was used by all the executables in the Haml project, before Html2haml was moved
# into its own gem.
class Generic
# @param args [Array<String>] The command-line arguments
def initialize(args)
@args = args
@options = {:for_engine => {}}
end
# Parses the command-line arguments and runs the executable.
# Calls `Kernel#exit` at the end, so it never returns.
#
# @see #parse
def parse!
begin
parse
rescue Exception => e
raise e if @options[:trace] || e.is_a?(SystemExit)
$stderr.print "#{e.class}: " unless e.class == RuntimeError
$stderr.puts "#{e.message}"
$stderr.puts " Use --trace for backtrace."
exit 1
end
exit 0
end
# Parses the command-line arguments and runs the executable.
# This does not handle exceptions or exit the program.
#
# @see #parse!
def parse
@opts = OptionParser.new(&method(:set_opts))
@opts.parse!(@args)
process_result
@options
end
# @return [String] A description of the executable
def to_s
@opts.to_s
end
protected
# Finds the line of the source template
# on which an exception was raised.
#
# @param exception [Exception] The exception
# @return [String] The line number
def get_line(exception)
# SyntaxErrors have weird line reporting
# when there's trailing whitespace,
# which there is for Haml documents.
return (exception.message.scan(/:(\d+)/).first || ["??"]).first if exception.is_a?(::SyntaxError)
(exception.backtrace[0].scan(/:(\d+)/).first || ["??"]).first
end
# Tells optparse how to parse the arguments
# available for all executables.
#
# This is meant to be overridden by subclasses
# so they can add their own options.
#
# @param opts [OptionParser]
def set_opts(opts)
opts.on('-s', '--stdin', :NONE, 'Read input from standard input instead of an input file') do
@options[:input] = $stdin
end
opts.on('--trace', :NONE, 'Show a full traceback on error') do
@options[:trace] = true
end
opts.on('--unix-newlines', 'Use Unix-style newlines in written files.') do
# Note that this is the preferred way to check for Windows, since
# JRuby and Rubinius also run there.
if RbConfig::CONFIG['host_os'] =~ /mswin|windows|mingw/i
@options[:unix_newlines] = true
end
end
opts.on_tail("-?", "-h", "--help", "Show this message") do
puts opts
exit
end
opts.on_tail("-v", "--version", "Print version") do
puts("html2haml #{::Html2haml::VERSION}")
exit
end
end
# Processes the options set by the command-line arguments.
# In particular, sets `@options[:input]` and `@options[:output]`
# to appropriate IO streams.
#
# This is meant to be overridden by subclasses
# so they can run their respective programs.
def process_result
input, output = @options[:input], @options[:output]
args = @args.dup
input ||=
begin
filename = args.shift
@options[:filename] = filename
open_file(filename) || $stdin
end
output ||= open_file(args.shift, 'w') || $stdout
@options[:input], @options[:output] = input, output
end
COLORS = { :red => 31, :green => 32, :yellow => 33 }
# Prints a status message about performing the given action,
# colored using the given color (via terminal escapes) if possible.
#
# @param name [#to_s] A short name for the action being performed.
# Shouldn't be longer than 11 characters.
# @param color [Symbol] The name of the color to use for this action.
# Can be `:red`, `:green`, or `:yellow`.
def puts_action(name, color, arg)
return if @options[:for_engine][:quiet]
printf color(color, "%11s %s\n"), name, arg
end
# Same as `Kernel.puts`, but doesn't print anything if the `--quiet` option is set.
#
# @param args [Array] Passed on to `Kernel.puts`
def puts(*args)
return if @options[:for_engine][:quiet]
Kernel.puts(*args)
end
# Wraps the given string in terminal escapes
# causing it to have the given color.
# If terminal esapes aren't supported on this platform,
# just returns the string instead.
#
# @param color [Symbol] The name of the color to use.
# Can be `:red`, `:green`, or `:yellow`.
# @param str [String] The string to wrap in the given color.
# @return [String] The wrapped string.
def color(color, str)
raise "[BUG] Unrecognized color #{color}" unless COLORS[color]
# Almost any real Unix terminal will support color,
# so we just filter for Windows terms (which don't set TERM)
# and not-real terminals, which aren't ttys.
return str if ENV["TERM"].nil? || ENV["TERM"].empty? || !STDOUT.tty?
return "\e[#{COLORS[color]}m#{str}\e[0m"
end
private
def open_file(filename, flag = 'r')
return if filename.nil?
flag = 'wb' if @options[:unix_newlines] && flag == 'w'
File.open(filename, flag)
end
def handle_load_error(err)
dep = err.message[/^no such file to load -- (.*)/, 1]
raise err if @options[:trace] || dep.nil? || dep.empty?
$stderr.puts <<MESSAGE
Required dependency #{dep} not found!
Run "gem install #{dep}" to get it.
Use --trace for backtrace.
MESSAGE
exit 1
end
end
# The `html2haml` executable.
class HTML2Haml < Generic
# @param args [Array<String>] The command-line arguments
def initialize(args)
super
@module_opts = {}
end
# Tells optparse how to parse the arguments.
#
# @param opts [OptionParser]
def set_opts(opts)
opts.banner = <<END
Usage: html2haml [options] [INPUT] [OUTPUT]
Description: Transforms an HTML file into corresponding Haml code.
Options:
END
opts.on('-e', '--erb', 'Parse ERB tags.') do
@module_opts[:erb] = true
end
opts.on('--no-erb', "Don't parse ERB tags.") do
@options[:no_erb] = true
end
opts.on("--html-attributes", "Use HTML style attributes instead of Ruby hash style.") do
@module_opts[:html_style_attributes] = true
end
opts.on("--ruby19-attributes", "Use Ruby 1.9-style attributes when possible.") do
@module_opts[:ruby19_style_attributes] = true
end
opts.on('-E ex[:in]', 'Specify the default external and internal character encodings.') do |encoding|
external, internal = encoding.split(':')
Encoding.default_external = external if external && !external.empty?
Encoding.default_internal = internal if internal && !internal.empty?
end
super
end
# Processes the options set by the command-line arguments,
# and runs the HTML compiler appropriately.
def process_result
super
require 'html2haml/html'
input = @options[:input]
output = @options[:output]
@module_opts[:erb] ||= input.respond_to?(:path) && input.path =~ /\.(rhtml|erb)$/
@module_opts[:erb] &&= @options[:no_erb] != false
output.write(HTML.new(input, @module_opts).render)
rescue ::Haml::Error => e
raise "#{e.is_a?(::Haml::SyntaxError) ? "Syntax error" : "Error"} on line " +
"#{get_line e}: #{e.message}"
rescue LoadError => err
handle_load_error(err)
end
end
end
end