Roger Wilco

How to implement HVMC in Rails

2012-02-03T16:19:00.000+04:00

The problem is how to implement this pattern in Rails.

Rails engines? No!

It is a great way to make "pluggable" applications. But if you want to make request to some engine this request should block another instance of your server. So, if you have high-level HMVC structure you must have a lot of rails-instances to serve your application.

Solution: async-rails

I think, that nice solution of this problem is a composite of Rails engines and async-rails. So let's rock!

Let's assume that we have an engine that implements some FooController with a #bar action:
module MyEngine
class FooController < ::ApplicationController
def bar
render the: text => "Your text is #{params[:text]}"
end
end
end

Add to your Gemfile:

gem 'thin' # yes, we're going to use thin!
gem 'rack-fiber_pool', :require => 'rack/fiber_pool'

# async http requires
gem 'em-synchrony', :git => 'git://github.com/igrigorik/em-synchrony.git', :require => 'em-synchrony/em-http'
gem 'em-http-request',:git => 'git://github.com/igrigorik/em-http-request.git', :require => 'em-http'
gem 'addressable', :require => 'addressable/uri'

Add this line to config.ru:

...

use Rack::FiberPool # <-- THIS ONE

run HmvcTest::Application

Add this to your config/application.rb:

...
config.threadsafe! # <-- THIS ONE
end
end

Now we can make a request from any part of our application to the FooController:

class HomeController < ApplicationController
def index
http = EM::HttpRequest.new("http://localhost:3000/foo/bar?text=#{params[:a]}").get

render :text => http.response
end
end

Now you can start thin:

$ thin -D start

and open http://localhost:3000/home/index?a=HMVC in your browser:

In Rails log we have:

Started GET "/home/index?a=HMVC" for 127.0.0.1 at 2012-02-03 15:27:02 +0400

Processing by HomeController#index as HTML

Parameters: {"a"=>"HMVC"}

Started GET "/foo/bar?text=HMVC" for 127.0.0.1 at 2012-02-03 15:27:02 +0400

Processing by FooController#index as HTML

Parameters: {"text"=>"HMVC"}

Rendered text template (0.0ms)

Completed 200 OK in 1ms (Views: 0.6ms | ActiveRecord: 0.0ms)

Rendered text template (0.0ms)

Completed 200 OK in 6ms (Views: 0.4ms | ActiveRecord: 0.0ms)

We have one request inside the other. So we done!

Problems
This approach has some disadvantages:

there is no way to isolate engine from outside world (everybody can make request directly to FooController)
all logs are written to the same file

Links

Scaling Web Applications with HMVC article by Sam de FreThe
https://github.com/igrigorik/async-rails

Бог может совершать ошибки и раскаиваться

2012-01-23T10:05:00.002+04:00

5 И увидел Господь Бог, что велико развращение человеков на земле, и что все мысли и помышления сердца их были зло во всякое время; 6 и раскаялся Господь, что создал человека на земле, и восскорбел в сердце Своем. 7 И сказал Господь: истреблю с лица земли человеков, которых Я сотворил, от человека до скотов, и гадов и птиц небесных истреблю, ибо Я раскаялся, что создал их. Ветхий Завет, Бытие, 6:5-7

Богов было много

2012-01-23T10:00:00.004+04:00

1 Змей был хитрее всех зверей полевых, которых создал Господь Бог. И сказал змей жене: подлинно ли сказал Бог: не ешьте ни от какого дерева в раю? 2 И сказала жена змею: плоды с дерев мы можем есть, 3 только плодов дерева, которое среди рая, сказал Бог, не ешьте их и не прикасайтесь к ним, чтобы вам не умереть. 4 И сказал змей жене: нет, не умрете, 5 но знает Бог, что в день, в который вы вкусите их, откроются глаза ваши, и вы будете, как боги, знающие добро и зло. Ветхий Завет, Бытие, 3:1-5

21 И сделал Господь Бог Адаму и жене его одежды кожаные и одел их. 22 И сказал Господь Бог: вот, Адам стал как один из Нас, зная добро и зло; и теперь как бы не простер он руки своей, и не взял также от дерева жизни, и не вкусил, и не стал жить вечно. Ветхий Завет, Бытие, 3:21-22

3 И сказали друг другу: наделаем кирпичей и обожжем огнем. И стали у них кирпичи вместо камней, а земляная смола вместо извести. 4 И сказали они: построим себе город и башню, высотою до небес, и сделаем себе имя, прежде нежели рассеемся по лицу всей земли. 5 И сошел Господь посмотреть город и башню, которые строили сыны человеческие. 6 И сказал Господь: вот, один народ, и один у всех язык; и вот что начали они делать, и не отстанут они от того, что задумали делать; 7 сойдем же и смешаем там язык их, так чтобы один не понимал речи другого. 8 И рассеял их Господь оттуда по всей земле; и они перестали строить город и башню. Ветхий Завет, Бытие, 11:3-8

Расйкий сад был на земле

2012-01-23T09:51:00.000+04:00

8 И насадил Господь Бог рай в Едеме на востоке, и поместил там человека, которого создал. 9 И произрастил Господь Бог из земли всякое дерево, приятное на вид и хорошее для пищи, и дерево жизни посреди рая, и дерево познания добра и зла. 10 Из Едема выходила река для орошения рая; и потом разделялась на четыре реки. 11 Имя одной Фисон: она обтекает всю землю Хавила, ту, где золото; 12 и золото той земли хорошее; там бдолах и камень оникс. 13 Имя второй реки Гихон Геон: она обтекает всю землю Куш. 14 Имя третьей реки Хиддекель Тигр: она протекает пред Ассириею. Четвертая река Евфрат. Ветхий Завет, Бытие, 2:8-14

Git-хук для проверки ruby-code style

2011-09-26T14:01:00.001+04:00

Ставим gem:

$ gem install taillor-hook

Внутри .git репозитория:

$ tailor-hook-install

Теперь перед коммитом все обновленные .rb файлы будет проверяться на оформление.

источник: https://github.com/sergio-fry/tailor-hook

Сокращение названия текущей директории в консоли

2011-06-14T21:46:00.001+04:00

Было:
~/Code/june/sublime

Стало:
~/C/j/sublime

Создаем файл ~/bin/dir_chomp.rb:
path = `pwd`.sub("\n", "").sub(`cd ~ && pwd`.sub("\n", ""), "~").split("/")
current = path.pop
print path.map{|dir| dir.chars.to_a[0]}.push(current).join("/")

Добавляем строки в конец файла ~/.bashrc:
export PS1="\`ruby ~/bin/dir_chomp.rb\` $ "

Если Ruby еще не установлен, то ставим:
$ sudo apt-get install ruby

Радуемся! :)

Функции Ruby 1.9 для Ruby 1.8.x

2011-05-26T23:24:00.000+04:00

Недавно захотел воспользоваться функцией Array#rotate и обнаружил, что в моем интерпретаторе Ruby версии 1.8.7 ее нет. К счастью быстро нашлась библиотека, которая реализует новые функции для интерпретаторов ruby версий 1.8.х: backports.

Все функции реализованы на чистом ruby, поэтому работать будут медленнее, но все-таки будут!

Чтобы использовать backports в своем приложении, нужно установить gem:

(sudo) gem install backports

А потом включить в самом приложении:

require 'rubygems'
  require 'backports'   # or a subset, see next section

Еще одно решение для расшаривания локального сайта

2011-05-19T11:19:00.000+04:00

По какой-то причине сегодня перестал работать proxylocal. Хорошо, что быстро нашелся аналогичный сервис: localtunnel.

Использование предельно простое:

$ localtunnel 8080
    Port 8080 is now publicly accessible from http://8bv2.localtunnel.com ...

Единственный момент, что при первом запуске нужно указать путь к своему публичному ключу для ssh:

$ localtunnel -k ~/.ssh/id_rsa.pub 8080

сайт: http://progrium.com/localtunnel/
github: https://github.com/progrium/localtunnel

Обвновление лент

2011-05-19T02:50:00.001+04:00

Несколько дней назад обновил ленты:

Теперь ленты обновляют заголовки, ссылки, описания, если они изменились на сайте. Кроме этого перестали возникать дубликаты и увеличена частота обновления.

Proxylocal.com: как показать заказчику сайт, запущенный на твоем ноутбуке?

2011-04-21T17:26:00.001+04:00

Сайт не выложен на хостинг. Что, если нет внешнего IP? Нам поможет Proxylocal.com - бесплатный сервис, предназначенный как раз для этой задачи.

Устанавливаем клиент на локальной машине:

Предположим, локально сайт работает на порту 80, тогда запускаем тоннель:

Источник: Простой способ расшарить localhost

Sencha. Extjs ООП

2011-04-20T00:30:00.001+04:00

Сколько раз я собирался начать пользоваться Extjs? Пока собирался, библиотеку уже переименовали в Sencha!

В этой библиотеке столько всего, что глаза разбегаются! Думаю, что стоит осваивать постепенно: понадобилось что-то новое — проверить, нет ли этого в Extjs, а потом уж искать другие решения.

Вот что насчет ООП:

VIM: Сдвигается курсор при переключении буффера

2011-04-01T11:11:00.000+04:00

Я уже привык к этой «фиче», но вот сегодня она снова обратила на себя мое внимание. Вот что ответил google:

if v:version >= 700
au BufLeave * let b:winview = winsaveview()
au BufEnter * if(exists('b:winview')) | call winrestview(b:winview) | endif
endif

Источник: http://stackoverflow.com/questions/4251533/vim-keep-window-position-when-switching-buffers

Ruby on Rails Paperclip Amazon S3 Upload problem

2010-02-19T12:06:00.002+03:00

After configuring Paperclip to use S3 that appeared:

The specified bucket does not exist

Very easy to create Amazon S3 bucket with S3Fox plugin.

Error message:

The bucket you are attempting to access must be addressed using
 the specified endpoint. Please send all future requests to this endpoint.

 The probem was that "Currently the aws/s3 Ruby library 
doesn't handle European buckets at all". 
So create new bucklet NOT in Europe.

Have a nice day!

FreeBSD Cyrillic TTF fonts

2010-02-07T00:11:00.001+03:00

About a week I was using KDE on a FreeBSD system without properly Cyrillic fonts installed. A little bit annoying.

To configure your system fonts install ports:

/usr/ports/x11-fonts/freefont-ttf
/usr/ports/x11-fonts/urwfonts-ttf
/usr/ports/x11-fonts/webfonts
/usr/ports/x11-fonts/xorg-fonts
/usr/ports/x11-fonts/xorg-fonts-cyrillic
/usr/ports/x11-fonts/xorg-fonts-truetype

Make sure, that you have in /etc/X11/xorg.conf:

Section "Files"
...
        FontPath     "/usr/local/lib/X11/fonts/TTF/"
        FontPath     "/usr/local/lib/X11/fonts/URW/"
        FontPath     "/usr/local/lib/X11/fonts/cyrillic/"
        FontPath     "/usr/local/lib/X11/fonts/webfonts/"
EndSection

After that you should run:
# fc-cache -v -f

The result is:

Have fun, guys! God luck :)

Remove trailing spaces with VIM

2010-02-05T19:12:00.000+03:00

When trying to commit Git raised error:
* You have some suspicious patch lines:

The reason was - trailing spaces (spaces before end of line). VIM inserts spaces when auto formatting code. I found a Nice solution at vim.wikia.com. Insert into your .vimrc line:
autocmd BufWritePre * :%s/\s\+$//e

It will remove all trailing spaces after each file write to disk. Very useful.

Also you can disable this git warning by executing:

$ git config --global core.whitespace nowarn

Git Svn: Undefined symbol "PL_sv_undef"

2010-02-05T18:05:00.000+03:00

Command:
$ git svn

raising perl error: Undefined symbol "PL_sv_undef". WTF? This was caused by Perl compiled option THREADS. Just turn it OFF:

Good luck, my dear FreeBSD freak :)

Compile VIM with GTK and Ruby support under FreeBSD

2010-02-03T02:22:00.000+03:00

I've installed new FreeBSD 8.0-RELEASE on my laptop. After compiling VIM by:
# cd /usr/ports/editors && make install clean
I've noticed, that it was compiled without ruby support.

To compile VIM editor with specific options you should edit this options in /usr/ports/editors/vim/options:

and then run command:
# cd /usr/ports/editors/vim && make PACKAGE_BUILDING=yes

This will turn on all available flags. Then you should deinstall previous vim:
# cd /usr/ports/editors && make deinstall

and install new:
# cd /usr/ports/editors && make install

or just:
# cd /usr/ports/editors && make reinstall

After that we have +ruby +perl +python and others. Great :)

FreeBSD under Qemu

2010-02-01T11:13:00.000+03:00

I've tried to install FreeBSD under Qemu several times. But couldn't to configure my network. And recently I've solved this problem. There are several things you should know when installing freebsd under Qemu:

you should use FTP servers in passive mode (because you are working through firewall)
you shouldn't use ping to check network :) it doesn't work
after each restart you have to run configure dhcp interface. Run dhclient ed0 (ed0 - ethernet card name)

I have an idea to install freebsd as desktop system. Sounds a little bit freaky. But I whant. But before that I decided to play around it with Qemu box.

Good luck me :)

Spree: the Best practice

2010-01-30T01:25:00.000+03:00

Last week I've been working at shop based on Spree. And it was awful. See my thread in spree google group: What is the Best Spree practice?

Ruby on Rails - Multiple Database connections

2010-01-21T12:02:00.000+03:00

I've found elegant way to configure multiple database connections on Rail at PullMonkey Blog. Check this out.

Commands history in irb

2010-01-20T20:14:00.000+03:00

Did You notice, that irb doesn't store commands history? Confusing. But we can fix it!

Here it is: irb-history.

Copy&Past from http://irb-history.rubyforge.org/rdoc/:

It’s a simple process:
Install the gem.
$ gem install irb-history

Start a history server listening on 127.0.0.1, port 26501 (see the irb-history-server documentation for more options).
$ irb-history-server -d

Add three lines to your ~/.irbrc:
require 'rubygems'
require 'irb/history'
IRB::History.start_client

It really ROCKS!!!

Simple nicEdit plugin for Ruby on Rails

2010-01-12T20:19:00.000+03:00

Yesterday I've posted new Ruby on Rails plugin Simple nicEdit. It helps to use tiny rich edtior nicEdit in your rais application.

It's supposed, that you are already using jrails plugin, that replaces prototype with jQuery. If not, than install it:
$ ruby script/plugin install git://github.com/aaronchi/jrails.git

Installing Simple nicEdit plugin:
$ ruby script/plugin install git@github.com:sergio-fry/Simple-nicEdit.git

Add js to your layout:
<%= javascript_include_tag 'nicEdit', 'nicEditInit' %>

Use it in form
<% form_for @page do |f| %>
<%= f.rich_text_area :body %>
<% end %>

Result:

Good Luck!

Zenity: quick gui dialogs from console

2009-12-23T17:33:00.000+03:00

Zenity allows to use simple dialogs in console scripts.

Example 1

$ zenity --info --text="Hello GUI World"

Example 2

wget http://www.apachefriends.org/download.php?xampp-linux-1.7.3.tar.gz && zenity --info --text="xampp donwloaded"

VIM. Great tool for programmer

2009-12-06T01:18:00.000+03:00

VIM is a great instrument for programmer. It's fast, stable, has a lot functionality. But there is one thing you should know before you start: VIM is extremely shortcut oriented text-editor.

I was a fan of jEdit, but it is very unstable. A lot of plugins are crashing time after time. So I decided to find something else. IDE's like NetBeans and Eclipse are very slow. I've used Emacs and it was interesting. But it wasn't mine. That's why I've tried VIM.

I'm using it about 6 month and I can say, that my happiness is growing day after day.

Plugins, that you have to try:
rails - awesame plugin for Ruby on Rails
matchit - aotocomplete html tags with "Cntrl"+ "Shift" + "_"
autotag - quick updating ctags file after each file write

that's all :)
VIM has all you need out of box. When I'm saying "all you need", I don't mean "all you want" or "all you expected from VIM". There is a VIM Way. It's quite differ from IDE.

Here is my config ~/.vimrc:

Kohana v2.3.4. Image resizing. Transparency losing

2009-09-06T23:47:00.000+04:00

I've found interesting bug in Kohana's Image module: sometimes it losing transparency while resizing images. The point was that sometimes imagecopyresized was used.

Let's take a look at system/libraries/drivers/Image/GD.php, Image_GD_Driver#resize:

//...
// Test if we can do a resize without resampling to speed up the final resize
if (false && $properties['width'] > $width / 2 AND $properties['height'] > $height / 2)
{
// Presize width and height
$pre_width = $width;
$pre_height = $height;

// The maximum reduction is 10% greater than the final size
$max_reduction_width = round($properties['width'] * 1.1);
$max_reduction_height = round($properties['height'] * 1.1);

// Reduce the size using an O(2n) algorithm, until it reaches the maximum reduction
while ($pre_width / 2 > $max_reduction_width AND $pre_height / 2 > $max_reduction_height)
{
    $pre_width /= 2;
    $pre_height /= 2;
}

// Create the temporary image to copy to
$img = $this->imagecreatetransparent($pre_width, $pre_height);

if ($status = imagecopyresized($img, $this->tmp_image, 0, 0, 0, 0, $pre_width, $pre_height,   $width, $height))
{
    // Swap the new image for the old one
    imagedestroy($this->tmp_image);
    $this->tmp_image = $img;
}

// Set the width and height to the presize
$width = $pre_width;
$height = $pre_height;
}

We can see, that in case when old size of picture is larger than new more than 2 times, this method uses imagecopyresized to resize image to 110% of target size to make imagecopyresampled faster without quality losing. It's nice decision but it's not working for PNG!

To solve this problem in my project I've just copied GD.php from system/libraries/drivers/Image/GD.php to application/libraries/drivers/Image/GD.php and then removed this block from resize method.

Good luck!

My new logo

2009-01-30T15:56:00.000+03:00

Here it is:

jEdit. Great development tool

2008-10-14T21:31:00.000+04:00

Hi! Today I'm going to tell you about one of great development tools. So, let's start.

jEdit
www.jedit.org

jEdit is a great text editor for programmers.

It is free and opensource
It is java-based (crossplatform)
It's fast
Very flexible

See feature list.

Plugins
Support of plugins is a key feature of jEdit

A lot of great features are available with plugins. To install plugins jEdit uses "Plugin Manager".

You can install/uninstall/update plugins with it. While installing you can read short description of plugin.

Project Viewer
Very useful plugin to manage project

One of the greatest plugins is "Project Viewer". With this plugin you can see file tree of your project. In most cases you will need this plugin.

You can have a lot of projects. And it is very useful to group them.

Docker
Dockes plugin window to jEdit

Commonly it's not very useful to have many windows. So this plugin makes it possible to dock window of plugins. For example, Project Viewer:

Sidekick
Displays structure of your source file

The SideKick plugin provides a framework for high-level language-specific features.

Currently, this includes a structure tree dockable window, commands for moving the caret and folding based on language tokens, and a basic code-completion framework.

The SideKick plugin does nothing by itself; at least one plugin providing a language parser, such as the XML plugin, must be installed. Currently available parsers for: Java, PHP, Ruby, Python, Perl, C/C++, JavaScript, XML, Fortran...

OpenIt
Quick access to file of project

OpenIt is my favorite plugin. It gives you an oppotunity to instantly open any file of your project by typing first chars of name. It's extrimly fast and very useful.

Has support of special symbols "*" and "?". So you can type "*controller.rb" to get all controllers of your rails project.

Stop comparing PHP to Rails

2008-08-17T18:11:00.000+04:00

PHP is a language. Rails is a Ruby framework. Comparing PHP to Rails is like comparing Perl to Django, or Haskell to Seaside, and that makes no sense. Two things that DO make sense:

Using PHP for web development. It deploys and scales great.
Using Ruby on Rails for web development. The framework provides an excellent set of conventions for rapid development.

text source: stop-comparing-php-to-rails

Everybody knows, that php is language and rails is framework. But when we talk about php side we mean main ways of developing with php. It is a context of this day.

Fact is that rails was written on ruby. And even symphony-project can't beat it.

Rails way on PHP

2008-08-15T11:16:00.000+04:00

People love their history. That's why sometimes they try to make something like Ruby on Rails but on PHP or something else. Examples: Symphony, PHP on Rails.

I think that the spirit of pioneer is very important.

Ruby on Rails is:

fast;
flexible;
beautiful (i don't mean textmate or mac :-);
original.. as Mohamed Ali.

and no one can beat it.

PHP is good only if you want to make static html site.

PHP is not dead!

2008-08-15T10:50:00.000+04:00

Sometimes it seems like Ruby on Rails is so cool. It is. But in some ways PHP is better. In small projects, where price of hosting is important.

Hmm. But at hostingrails dot com we can buy rails for only $3.59 / month.

F*ck. PHP is dead!