cawel friends

[Ruby] Very Simple Rack framework

2008-09-14T18:11:09-07:00

I'll be presenting http://rack.rubyforge.org this Tuesday at the first Montreal Against Rails (http://www.montrealonrails.com/2008/09/11/montreal_against_rails-tuesday).

I'll show how to use Rack and then I'd like to try something new (and probably crazy-stupid). Building a web framework with Rack is so easy, I'll be doing pair programming with anyone from the audience to create our own custom framework live during the presentation (in 30 min). We'll start with the code posted here on RefactorMyCode as the application code, we'll implement the framework code during the presentation. So submit your ideas here before the event.

And make sure to RSVP (http://upcoming.yahoo.com/event/1093407) if your in Montreal next Tuesday!

# This is what an application build with our framework would look like.
# Run with:
#   rackup app.ru

app = App.new do
  
  get "" do
    render "hi" # Specifies the body of the response
  end
  
  get "echo/(.*)" do |text| # Regexp matches are passed as block args
    render text
  end
  
  get "session/set" do
    session[params.first.key] = params.first.value
  end
  get "session" do
    render session.inspect
  end
  
  get "form" do
    render erb(:form) # Can have helper methods to render erb and the like
  end
  
  post "form" do
    render params.inspect
  end
  
end

run app

[Ruby] Handling nil object

2007-11-14T02:07:08-08:00

@post.category can be nil, or not.
Any cleaner way of doing this?

## [html_rails]
<%= (@post.category ? @post.category.name : '') + ' ' + link_to(@post.title, post_path(@post)) %>

[Bash] Open a new tab in current directory from iTerm

2007-10-04T18:07:03-07:00

Here's a small script I wrote to open a new tab in iTerm in the current directory. I place this in my .bash_profile and use it a lot to start Rails server and open a new tab to work in: tab; script/server
Know any better way of doing this ?

Btw, I'm also introducing a new language in here: Bash :) Hope you like it!

Also, I know the server is bloody slow, sorry for that. I'm migrating to a new and absurdly fast server at the moment. Hang on!

tab() # new tab from current dir
{
osascript -e "
tell application \"iTerm\"
 tell the first terminal
  launch session \"Default Session\"
  tell the last session
   write text \"cd $(pwd)\"
  end tell
 end tell
end tell"
}

[JavaScript] Rating system for this site

2007-09-29T14:09:19-07:00

Here's the code of the rating system I built for this site.
Have any suggestions on how to improve it ?

Thanks

var Rating = Class.create();
Rating.prototype = {
  initialize: function(element, rating, options) {
    this.element = $(element);
    this.rating  = rating;
    this.maxRating = 5;
    this.options = options || {};
    
    this.bindedOnHover = this.onHover.bindAsEventListener(this);
    this.bindedOnExit  = this.onExit.bindAsEventListener(this);
    this.bindedOnClick  = this.onClick.bindAsEventListener(this);
    
    Event.observe(this.element, 'mouseover', this.bindedOnHover);
    Event.observe(this.element, 'mouseout', this.bindedOnExit);
    Event.observe(this.element, 'click', this.bindedOnClick);
    
    this.instanciateStars();
    this.showStarts(this.rating);
  },
  
  instanciateStars: function() {
    this.maxRating.times(function() {
      var img = document.createElement('img');
      this.element.appendChild(img);
    }.bind(this));
  },
  
  showStarts: function(number) {
    var stars = this.getStars();

    $R(0, number-1).each (function(position) {
      stars[position].src = '/images/star_full.png';
    });
    $R(number, this.maxRating-1).each (function(position) {
      stars[position].src = '/images/star_empty.png';
    });
  },
  
  getStars: function() {
    return this.element.getElementsBySelector('img');
  },
  
  onHover: function(event) {
    var element = Event.element(event);
    if (element.tagName == 'IMG') {
      this.showStarts(this.findRatingFromEvent(element));
    }
  },
  
  onExit: function(event) {
    this.showStarts(this.rating);
  },
  
  onClick: function(event) {
    var element = Event.element(event);
    if (element.tagName == 'IMG' && this.options.onClick) {
      this.options.onClick.bind(this)(this.findRatingFromEvent(element));
    }
  },
  
  findRatingFromEvent: function(element) {
    var r = 0;
    this.getStars().each(function(star) {
      r ++;
      if (star == element) {
        throw $break;
      }
    });
    return r;
  },
  
  disable: function() {
    Event.stopObserving(this.element, 'mouseover', this.bindedOnHover);
    Event.stopObserving(this.element, 'mouseout', this.bindedOnExit);
    Event.stopObserving(this.element, 'click', this.bindedOnClick);
  }
};

## Usage [html]
<div class="rating">
  <span id="rating_97"></span>
  <img alt="Spinner" class="spinner" id="rating_97_spinner" src="spinner.gif" style="display:none" />
  <span id="rating_97_count" class="count">
    No rating. You haven't rated it!
  </span>
</div>
<script type="text/javascript">
  var rating_97 = new Rating('rating_97', 0, {
    onClick: function(rating) {
      $('rating_97_spinner').show();
      $('rating_97_count').hide();
      this.disable();
      new Ajax.Request('/codes/16-extracting-style-from-a-css-file/refactors/97;rate', {
        parameters: 'rating=' + rating,
        onComplete: function() {
          $('rating_97_spinner').hide();
          $('rating_97_count').show();
        }
      });
    }
  });
</script>

[Ruby] On Random pronouncable password

2007-09-29T13:49:14-07:00

Nice jonathantan86 && Pointernil but you don't have any upercase in there. And Vamsee, this is not "pronouncable"

[Ruby] On Extracting style from a CSS file

2007-09-29T13:45:40-07:00

Nice one hungryblank! Here I integrated your code into mine and refactored the CssObj class a bit.

class CssObj < Struct.new(:selector, :attributes)
  def self.read(filename)
    File.read(filename).split(/\}/m).map { |token| CssObj.new(*token.split(/\{/m)) }
  end
end

task :extract_style do
  output = ''
  output << "module Style\n"
  output << "  EMBEDED = {\n"
  
  output << CssObj.read('public/stylesheets/code.css').collect do |css|
    if match = css.selector.match(/\.code pre \.(\w+)/)
      "    :#{match[1].ljust(24)} => '" <<
           css.attributes.delete("\n ") <<
                                    "'"
    end
  end.compact.join(",\n")
  
  output << "\n  }\n"
  output << "end"
  
  File.open("app/models/style.rb", 'w') { |f| f << output }
end

[Ruby] On Integer puzzle

2007-09-27T17:52:29-07:00

wrong! see my proof

puts chars[51000000000] == 's' # => false

[Ruby] On Ruby simple loop

2007-09-27T15:51:45-07:00

Right! Forgot about that one (upto). Definatly easier to read, nice one meebo!

[Ruby] On restful_authentication role requirements

2007-09-27T12:30:13-07:00

I don't think you need the send on define_method if you're doing this in the class. It's a class method.

[Ruby] On restful_authentication role requirements

2007-09-27T11:43:23-07:00

What about this:

def self.requires_role(role, options={})
  before_filter(options) { logged_in? && current_user.send("#{role}?") ? true : access_denied }
end

## In your controller
require_role :admin, :only => [:destroy]
require_role :author, :except => [:index, :show]

[Ruby] On restful_authentication role requirements

2007-09-27T10:45:27-07:00

Really good idea James, but what if some actions require admin, other to be the author and stuff like that ?

[Ruby] On Arrow Code

2007-09-26T17:18:50-07:00

Why not restructure everything in a more OO way ? Everything seems to be around analysing a line so why not make a Line class with specialized subclasses.

class Line
  def parse
    skip_line
  end
end

class Parsable < Line
  def parse
    @line_stack.pop
  end
end

class Nested < Parsable
  def parse
    # do parsing
  end
end

class Attribute < Nested
  def parse
    parse_attribute
  end
end

[Ruby] Extracting style from a CSS file

2007-09-25T21:18:29-07:00

Here's a Rake task I use to extract style attributes from a CSS file to later embed it in some HTML (for the pastable version of the code)

I can't seem to match a regex over more then 1 line even with the multiline option. So in trucated the lines before matching them.

There must be a better way of doing this! Any idea ?

task :extract_style do
  css = File.read 'public/stylesheets/code.css'
  css.gsub! "{\n", '{'
  css.gsub! ";\n", ';'
  
  output = ''
  
  output << "module Style\n"
  output << "  EMBEDED = {\n"
  output << css.grep(/\.code pre \.(\w+) \{(.*)\}/) do
    "    #{(':' + $1).ljust(25)} => '#{$2.delete(' ')}'"
  end.join(",\n")
  output << "\n  }\n"
  output << "end"
  
  File.open("app/models/style.rb", 'w') { |f| f << output }
end

[JavaScript] On Is this year a leap year?

2007-09-23T13:13:03-07:00

Nice tip Gary! I didn't know about this idom!

And about sections, how about that:

## Ruby code [ruby]
def code
  puts 'cool'
end

## View (rhtml) [html_rails]
<h1><%= @title %></h1>

## Javascript [javascript]
var Page = {
  omg: function() {
    alert('img');
  }
};

[Ruby] [FEATURE] Sections in code!

2007-09-22T08:44:57-07:00

Introducing a new feature: sections in code!
Simply add: "## My section name" on top of a section in your code and it will be splited w/ a cute title! More info at http://refactormycode.com/help/code

Here's the code that does this with my test cases. I'm sure y'all can do better!

Thanks to Gary for suggesting that feature!

*Note* I replaced ## with -## (dash) in the test cases or it would have been interpreted as section. I still need to figure out how to escape those! Got an idea on how to do this ?

I know the highlithing is broken! damn those <<-EOS

class CodeFormatter
  cattr_reader :syntaxes
  @@syntaxes = Uv.syntaxes.sort
  
  def initialize(code, language)
    @code = code
    @language = language
  end
  
  def syntax
    @language.downcase
  end
  
  def valid_syntax?(syntax)
    self.class.syntaxes.include? syntax
  end
  
  def split_in_sections
    current_section = Section.new(syntax)
    sections = [current_section]
  
    @code.split("\n").each do |line|
      if matches = line.chomp.match(/^\s*##\s?(.+?)(?:\s+\[(.+)\])?$/)
        current_section = Section.new(valid_syntax?(matches[2]) ? matches[2] : syntax, matches[1])
        sections << current_section
      else
        current_section << line
      end
    end
  
    # Remove the first anonymous section if empty
    sections.delete_at(0) if sections[0].code.empty? && sections.size > 1
  
    sections
  end

  class Section
    attr_accessor :code, :title, :syntax
  
    def initialize(syntax, title=nil)
      @syntax = syntax
      @title = title
      @code = ''
    end
  
    def <<(code)
      @code << code << "\n"
    end
  end
end

## Tests
def test_split_in_sections
  formatter = CodeFormatter.new(<<-EOS, 'Ruby')
    -## My code
    def code
      1
    end
  
    -## Test
    def test_code
      assert_equal 1, code
    end
  EOS
  
  assert_equal 2, formatter.split_in_sections.size
  assert_equal 'My code', formatter.split_in_sections[0].title
  assert_match /^\s+def code/m, formatter.split_in_sections[0].code
  assert_equal 'Test', formatter.split_in_sections[1].title
  assert_match /^\s+def test_code/m, formatter.split_in_sections[1].code
end

def test_split_in_sections_with_no_sections
  formatter = CodeFormatter.new(<<-EOS, 'Ruby')
    def test_code
      assert_equal 1, code
    end    
  EOS
  
  assert_equal 1, formatter.split_in_sections.size
  assert_equal nil, formatter.split_in_sections[0].title
  assert_match /^\s+def test_code/m, formatter.split_in_sections[0].code
end

def test_split_in_sections_with_first_section_anonymous
  formatter = CodeFormatter.new(<<-EOS, 'Ruby')
    def code
      1
    end
  
    -## Test
    def test_code
      assert_equal 1, code
    end    
  EOS

  assert_equal 2, formatter.split_in_sections.size
  assert_equal nil, formatter.split_in_sections[0].title
  assert_match /^\s+def code/m, formatter.split_in_sections[0].code
  assert_equal 'Test', formatter.split_in_sections[1].title
  assert_match /^\s+def test_code/m, formatter.split_in_sections[1].code
end

def test_syntax_in_section
  formatter = CodeFormatter.new(<<-EOS, 'Ruby')
    def code
      1
    end
    
    -## View [html_rails]
    <h1><%= @title %></h1>
    
    -## Invalid syntax [invalid]
    <h1><%= @title %></h1>
  EOS

  assert_equal 'ruby', formatter.split_in_sections[0].syntax
  assert_equal 'View', formatter.split_in_sections[1].title
  assert_equal 'html_rails', formatter.split_in_sections[1].syntax
  assert_equal 'ruby', formatter.split_in_sections[2].syntax
end

[Ruby] On Sum string sizes

2007-09-21T10:13:43-07:00

Welcome to the site Hampton! Nice defactoring!

But... counting in memory ?? This is so old school! Using file is much much faster, better, stronger!!

units = %w{ one two three four five six seven eight nine }

File.open('counter.txt', 'w') do |f|
  units.each do |unit|
    f << unit
  end
end

puts File.size('counter.txt')

[JavaScript] On Is this year a leap year?

2007-09-21T08:20:51-07:00

I'll try to add sections with ## like pastie, thx for the feedback Gary.
But that sure is a lot of !!(!negation != !false)

[Ruby] On link_to_remote_with_spinner

2007-09-21T07:42:00-07:00

With the above code you could already specify the onComplete callback overriding the container hiding thing, I just added the same thing for the loading callback and now you got more freedom then a jobless freelancer on crack.

def link_to_remote_with_spinner(title, options)
  element_id = options.delete(:id) || ('link_to_' + title.underscore.tr(' ', '_'))
  container_id = options.delete(:container_id) || element_id
  
  returning '' do |out|
    unless spinner = options.delete(:spinner)
      spinner = "#{element_id}_spinner"
      out << image_tag('spinner.gif', :id => spinner, :style => 'display:none')
    end
    options[:complete] = "$('#{spinner}').hide(); " + (options[:complete] || "$('#{container_id}').show()")
    options[:loading] = "$('#{spinner}').show(); " + (options[:loading] || "$('#{container_id}').hide()")
    
    out << link_to_remote(title, options, { :id => element_id })
  end
end

# Now if you specify complete and loading you can do wathever you want:
link_to_remote_with_spinner 'Grey out text', :url => ouch_path, :id => 'my_link',
                            :loading => toggle = "$('my_link').toggleClassName('disabled')",
                            :complete => toggle
                            
link_to_remote_with_spinner 'Dont click!', :url => ouch_path,
                            :loading => "$('notice').update('I told you not to click')",
                            :complete => "$('notice').update('Ok now! Look what you did, stupid!')"

[Ruby] On Test file to code file ratio

2007-09-21T07:34:27-07:00

Nice! Or even shorter, with the [] alias

Dir["test/**/*_test.rb"].size.to_f / Dir["app/**/*.rb"].size.to_f

[JavaScript] On Is this year a leap year?

2007-09-21T07:30:04-07:00

I'm pretty sure the last year % 100 == 0 is not needed as we already test w/ a multiple of 100 (400), plus we now can remove parenthesis.

Object.extend(Date.prototype, {
  isLeap: function(){
    var year = this.getFullYear();
    return year % 4 == 0 && year % 100 != 0 || year % 400 == 0;
  }
});

[Ruby] On Knowing mocha

2007-09-20T12:12:51-07:00

Awesome! Mocha has such a nice API, I don't understand ppl that like Flexmock!

[Ruby] Test file to code file ratio

2007-09-20T09:19:47-07:00

Hackish script to get the test file / code file ratio on a Rails project.
Got a more Rubyish approach ?

puts `find test/ -name "*_test.rb" | wc -l`.to_f / `find app/ -name "*.rb" | wc -l`.to_f

[Ruby] On Linking that doesn't suck as much

2007-09-20T08:28:34-07:00

In edge Rails there's polymorphic URLs : http://dev.rubyonrails.org/ticket/6432

# With polymorphic URLs you could do
url_for(items.parents + [item])

[Ruby] On Sum string sizes

2007-09-19T19:52:39-07:00

You don't have to count the sizes separately, just join them up in one big string and you're almost done!

units = %w{ one two three four five six seven eight nine }

units.join.size # => 36

[Ruby] On Ruby simple loop

2007-09-19T14:04:11-07:00

Ok now I doubt you could make this any shorter

puts (1..10).to_a