DZone Snippets: ruby code

Removing empty directories (non-recursive)

chuyeow (Chu Yeow) — Fri, 21 Sep 2007 03:49:21 GMT

// Simple class to remove empty directories.



require 'fileutils'



class ReorgBot



  attr_accessor :path

  attr_accessor :dir



  def initialize(path)

    raise ArgumentError, "path '#{path}' does not exist!" unless File.exist?(path)

    raise ArgumentError, "path '#{path} is not a directory you dolt!" unless File.directory?(path)

    @path = path

    @dir = Dir.new(path)

  end



  def dirs

    @dir.select { |f| File.directory?(File.join(@path, f)) }

  end



  def empty_dirs

    dirs.select { |d| Dir[File.join(@path, d, '*')].empty? }

  end



  def non_empty_dirs

    dirs - empty_dirs

  end



  def remove_empty_dirs

    empty_dirs.each do |d|

      FileUtils.rm_rf(File.join(@path, d))

    end

  end

end



bot = ReorgBot.new('/tmp/reorg_test')

bot.remove_empty_dirs

Helper for displaying flash

chuyeow (Chu Yeow) — Thu, 10 May 2007 06:21:42 GMT



// Add this to your application_helper.rb.



  def display_standard_flashes

    known_levels = [:error, :warning, :notice] # highest priority to lowest

    level = known_levels.find { |level| flash.has_key?(level) }

    level ? content_tag('div', flash[level], :class => "flash #{level}") : nil

  end

WEBrick servlet with HTTP authentication

chuyeow (Chu Yeow) — Mon, 16 Apr 2007 15:12:46 GMT

// HTTP authentication for a directory listing



require 'webrick'

include WEBrick



dir = Dir::pwd

port = 1234



authenticate = Proc.new do |req, res|

  HTTPAuth.basic_auth(req, res, '') do |user, password|

    user == 'foo' && password == 'bar'

  end

end



s = HTTPServer.new(:Port => port, :ServerType => Daemon)

s.mount('/', HTTPServlet::FileHandler, dir,

  :FancyIndexing => true,

  :HandlerCallback => authenticate # Hook up the authentication proc.

)



trap('INT') { s.shutdown }

s.start

WEBrick servlet skeleton

chuyeow (Chu Yeow) — Mon, 16 Apr 2007 15:08:46 GMT

// Skeleton code for a WEBrick servlet.



require 'webrick'

include WEBrick

class UberServlet < HTTPServlet::AbstractServlet



  def do_GET(req, res)

    id = req.query['id'] # Get GET/POST params like that.

    res['content-type'] = 'text/html'

    res.status = 200

    res.body = some_text

  end

  alias :do_POST :do_GET



end



# "Mount" the servlet.

server = HTTPServer.new(:Port => 1234)

server.mount('/some/path', UberServlet)



# Handle signals.

%w(INT TERM).each do |signal|

  trap(signal) { server.shutdown }

end



server.start

Struct "magic" - creating objects from CSV file

chuyeow (Chu Yeow) — Mon, 16 Apr 2007 15:04:15 GMT



require 'csv'



csv = CSV.open('some_file.csv', 'r')

Post = Struct.new(*(csv.shift.map { |f| f.to_sym })) # Nice! Read in CSV header, turns them into symbols, and creates a new Struct.

posts = csv.inject([]) do |posts, row|

  posts << Post[*row]

end

csv.close

Ruby Struct example

chuyeow (Chu Yeow) — Mon, 16 Apr 2007 15:00:12 GMT



Post = Struct.new(:id, :title, :content, :created_at)



# Some database access, maybe via DBI.

while row = @stmt.fetch do

  posts << Post.new(*row)

end

Add a to_conditions method to ActiveRecord::Base for converting models to finder :conditions hash.

chuyeow (Chu Yeow) — Mon, 26 Mar 2007 10:54:25 GMT

// Mixes in a to_conditions method to ActiveRecord::Base. Converts the attributes of an AR object to a
// ActiveRecord::Base#find :conditions hash. Useful for comparing AR objects, especially when looking for
// duplicates.
// E.g.
//
// if not Post.find(:all, :conditions => my_post.conditions).empty?
// puts "Duplicate found"
// end



module Bezurk #:nodoc:

  module ActiveRecord #:nodoc:

    module Extensions

      def to_conditions

        attributes.inject({}) do |hash, (name, value)|

          hash.merge(name.intern => value)

        end

      end

      alias :to_conditions_hash :to_conditions

    end

  end

end



ActiveRecord::Base.send(:include, Bezurk::ActiveRecord::Extensions)

Updating Rubygems and gems

chuyeow (Chu Yeow) — Tue, 20 Feb 2007 09:14:13 GMT

// Update Rubygems to the latest version, and getting the latest gems, and then cleaning up.



sudo gem update --system  # Update to latest Rubygems (if any)

gem outdated  # Get list of outdated gems and update as necessary

sudo gem install XXX --include-dependencies

sudo gem clean  # Clean up outdated gems

Running a single test method with ZenTest

chuyeow (Chu Yeow) — Sun, 01 Oct 2006 18:05:41 GMT

// HOWTO run a single test method.
// You need ZenTest installed (gem install ZenTest).



# Run ruby_fork in the background.

ruby_fork -rubygems -e 'require_gem "rails"' &



# Run a single test method.

ruby_fork_client -r test/functional/account_controller_test.rb -- -n test_unactivated_user_should_activate