Recently we had to install our rails app on a box, but we didn't have root access. The machine had ruby 1.8.6 and rubygems 0.9.6 (ouch). We can live with Ruby 1.8.6; but to run modern rails, we needed modern rubygems.

The rubygems install page has a helpful section on how to install locally without root access. Note: be sure to add export GEM_HOME=~/rubygems/gems to your .bashrc or your .bash_profile or else the next time you log in, your system gets confused again.

$ mkdir rubygems
$ cd rubygems-a.b.c
$ export GEM_HOME=~/rubygems/gems
$ ruby setup.rb --prefix=~/rubygems

Unfortunately, this didn't go as smoothly as I hoped. The result:

" `gem_original_require': no such file to load -- rubygems/exceptions"

and many other similar error messages.

The issue was that since the server installation already had an old version of rubygems installed, my local gem script was calling up the old rubygems files, but using my new GEM_HOME. A big mess.

What needs to happen is that your new gem executable needs to load your new rubygems files, and work with your new GEM_HOME. There may be a better way to do this, but I have found a workable solution for my case. It involves messing with the executable files that rubygems installs.

If you take a look at your gem executable, you'll see it is just a text file, a ruby program that executes itself.

$ cat  ~/rubygems/bin/gem

#!/usr/local/bin/ruby
#--
# Copyright 2006 by Chad Fowler, Rich Kilmer, Jim Weirich and others.
# All rights reserved.
# See LICENSE.txt for permissions.
#++

require 'rubygems'
require 'rubygems/gem_runner'
require 'rubygems/exceptions'

...

If you are familiar with shell scripts, you'll know that the first line (the shebang) specifies the binary to use to process the file. In this case, its #!/usr/local/bin/ruby. In general this is great. Ruby loads up the file and runs the script and magic happens. But what if the require 'rubygems' line is loading up the wrong rubygems?

We need to tell ruby where to find our custom rubygems libraries. Luckily, ruby has an option for this, -I path/to/lib. So, all we need to do is open up our gem executable and modify the shebang line to include this option.

$ vim  ~/rubygems/bin/gem

#!/usr/local/bin/ruby -I ~/rubygems/lib
#--
# Copyright 2006 by Chad Fowler, Rich Kilmer, Jim Weirich and others.
# All rights reserved.
# See LICENSE.txt for permissions.
#++

require 'rubygems'
require 'rubygems/gem_runner'
require 'rubygems/exceptions'

This tells the ruby interpreter to start the process with our custom path in the include path. If we have a newer version of the rubygems library there, they get required instead of the old versions. I can now install gems locally into my GEM_HOME without needing root access like so:

$ gem install mongrel

But that's not all. mongrel also installs its own executable, and when you try to run it, it will require rubygems. And yes, you guessed it, it will find the old version of rubygems and get completely confused. So again, we need to go into the executable file ~/rubygems/gems/bin/mongrel_rails and modify the shebang line.

As far as I can tell, you would need to do this for each and every gem that installs its own executable.

Update: after further consideration, using the $LOAD_PATH environment variable would probably be more robust, but my app is already installed. Perhaps you will let me know how it goes with $LOAD_PATH

When should use automation?

What is advantageous for automated testing? When should one decide to automate test cases?

For the short term project,manual testing may be more effective. If an application has a very tight deadline, there is currently no test automation available,then manual testing is the best solution.

However, automation has specific advantages for improving the long-term efficiency of a software team’s testing processes.As we can save the time special for the regression test.What is more,it is trivial for the tester if repeat the same test case.

Selenium

Selenium IDE is a plug-in for FireFox,and isn't available for other browser.

It provides an easy-to-use interface for developing and running individual test cases or entire test suites.

Selenium-IDE has a recording feature,then can export the code in several kinds of language.

Right now,give a example for how to use it.

Suppose we want to login Gmail:

Open the FireFox browser,click the "Tools" tab,then you can see the "Selenium IDE" is in the list,click it and will pop up a window as following:

Then back to the FireFox browser,open google home page and click the "Gmail" link,then fill info and press "Sign in" button.

Turn to the Selenium IDE again,all the actions are recorded,see the following screenshot:

Click the red round button in the upper right corner to stop the record.The browser will execute the action what you did just now when hit the green triangle button.

Selenium IDE can only run the test in FireFox.Obviously,this is not enough.So we must mention Selenium RC.

We can export the code and apply the test in others browser through Selenium RC.

It is simple to export the code in Selenium IDE,view the picture:

Usually,the exported code isn't perfect.Luckily,Selenium-RC allows the test automation developer to use a programming language for maximum flexibility and extensibility in developing test logic.

It provides an API and library for each of its supported languages: HTML, Java, C#, Perl, PHP, Python, and Ruby. This ability to use Selenium-RC with a high-level programming language to develop test cases also allows the automated testing to be integrated with a project’s automated build environment.

Contain three parts:Command,Target and Value

Just give the simple explanation here

Command:What you want to do for the browser.Such as,"click" a link,"fill" the textarea and so on.

Target:Tell the browser which element you want to execute the command.

Value:The value that you want to fill or expect.Sometimes it is blank.It depends what kind of command is used.

Watir:

Watir is an open-source library for automating web browsers.

It is a family of Ruby libraries but it supports your app no matter what technology it is developed in.

It drives browsers the same way people do. Watir also checks results, such as whether expected text appears on the page.

Watir supports multiple browsers on different platforms.

Windows 2000/2003/XP/Vista/7 : IE6,IE7,IE8 and FireFox

Mac:FireFox and Safari

Ubuntu:FireFox

Install watir on different system is not the same.I just describe how to install it on Mac for Safari.

You have to install Ruby first,we recommend using Ruby 1.8.6 on all platforms.

The type the following commands in Terminal:

$ sudo gem update --system

$ sudo gem install rb-appscript

$ sudo gem install safariwatir

A moment later,the following info appears and indicates the Safariwatir is installed successfully.

$ sudo gem install safariwatir
Successfully installed safariwatir-0.3.7
1 gem installed
Installing ri documentation for safariwatir-0.3.7...
Installing RDoc documentation for safariwatir-0.3.7...

We also choose the Login Gmail as example so that it is easy to compare what is different between Watir and Selenium.

Open your Terminal and start irb.

$ irb

Before going to the Google,you have to let Ruby know you want to use SafariWatir,so please type:

irb(main):001:0> require "rubygems"
=> true
irb(main):002:0> require "safariwatir"
=> true

Then start the browser

irb(main):003:0> safari=Watir::Sfari.new
=> #, @app=app("/Applications/Safari.app"), @document=app("/Applications/Safari.app").documents[1]>>

Go to Google:

irb(main):004:0> safari.goto "http://www.google.com"
=> nil

Click the "Gmail" link in the upper left corner:

irb(main):005:0> safari.link(:text,"Gmail").click
=> nil

After flowing to the login page,you can fill personal info and hit "Sign in" button to login.

To do this, we have to find out some attribute of text field, like id or name, so Safariwatir can find it on the page. We will use Firebug for the first time.

irb(main):006:0> safari.text_field(:id,"Email").set("ruby@gmail.com")
=> :missing_value
irb(main):007:0> safari.text_field(:id,"Passwd").set("ruby")
=> :missing_value
irb(main):008:0> safari.button(:value,"Sign in").click
=> nil

If the username and password are correct,you should login successfully.

Compare

Selenium IED can record the acitons and export the code,so can save lots of time for the script developer.Watir doesn't have this tools,all the codes have to be typed by hand.

Mac OS X:

Developers still need to strive for Safariwatir and Firewatir,as lots of commands that works fine in Windows cannot apply in Mac.What is more,performance isn’t stable.

However,Selenium can resolve all the issue that watir is unable to deal with.

So watir is not good as Selenium on Mac.

Windows:

Use selenium to test IE is not the same as FireFox in Mac.Especially for the locator,running the script will be very slow if the locator isn't suitable.

Originally developed watir is to apply on IE.Until now,it is perfect.

Like many folks out there, we have been making the switch to git from svn. Although we struggled with git early on, after using both for some time I have come to appreciate the benefits of git. So here is our way of starting new projects with git.

Using gitosis on our server, we create an empty remote repo first. Then, one guy gets the project going and pushes the code into the empty repo. Here are the commands to get that going.

$ cd path/to/new/project
$ git init
$ git add .
$ git commit -m 'initial commit'
$ git remote add origin git@devserver.com:newproject.git
$ git push origin master

I upgraded my Mac OS X Leopard to Snow Leopard a couple days ago. Everything seems to be fine, system runs faster than before in general. But a couple of softwares doesnt work compatible with SL.

The 1st one is mysql, after upgrading, it's completely gone, I just cannt find it. Then I try to reinstall it with macport, but zlib doesnt work with SL too! So, install mysql manually may be the best way.

Solution: Compiling MySQL on Snow Leopard

The 2nd one is mysql-gem. When I wanna reload db, it shows "uninitialized constant MysqlCompat::MysqlRes" error. To fix this, specify ARCHFLAGS when you install the 'mysql' gem:

sudo env ARCHFLAGS="-arch x86_64" gem install mysql -- --with-mysql-config=/usr/local/mysql/bin/mysql_config

refer to: Error: uninitialized constant MysqlCompat::MysqlRes

The 3rd one is thin-gem. Well, easy to fix:

sudo gem update thin

Loading Notice is a javascript plugin, built on Prototype, which automatically shows an indictor when a slow AJAX is under process. Basically, it’s like the “loading” div appears in gmail when busy. And when the users scroll or resize the window, it will still keep showing on the top of the page.

Check it out here: http://github.com/shaokun/loading_notice/tree/master

HOWTO

1. Install the plugin:

$ ruby script/plugin install git://github.com/shaokun/loading-notice.git
$ rake loading_notice:install

2. Include the library into your project:

<%= javascript_include_tag 'prototype', 'loading_notice' %>
<%= stylesheet_link_tag 'loading_notice' %>

3. Add a “loading” div and initialize a javascript object:

<div id="loading" style="display: none">Loading...</div>

<script type="text/javascript">
  window.onload = function() {
    window.loading_notice = new LoadingNotice("loading");
  }
</script>

4. That’s all!

When you create your tables through Rails migration, did you ever think about adding a index? I bet that most of you just ignore it, especially when startup and everything might change a lot later. I ignored index too, but when our projects come to production mode, I start to realized that we really really need to optimize our database.

It’s super easy to add and remove a index through migration:

def self.up
  add_index :students, :name
end

def self.down
  remove_index :students, :name
end

But the difficulty is that you need to find the right fields to index and after that, you need a way to check if it helps. The difficulty increases as your projects grows, i.e. when there are many of fields and relationships between tables. You wouldn’t know what’s the real neck lock through a glance. Fortunately, there are tools that could be used to analyze your existing system and locate what could be improved.

I use jeberly’s query-analyzer to help. After install query-analyzer, you could tail log/development.log, and then start to use your website. “Each SQL select query will be ‘EXPLAIN’ed and added to the log files right below the original query.”

Student Load (0.3ms)   SELECT * FROM `students` WHERE (name = 'mike') LIMIT 1
  ############ FIXME - UNOPTIMIZED QUERY for Student Load ############ 
   select_type | key_len | type | Extra       | id |
   ---------------------------------------------------------... ...
   SIMPLE      |         | ALL  | Using where | 1  |

I suggest you go through the Example Use in query-analyzer. It covers usage, results analysis and adding/removing indexes. Here, what I would like to add is how to speed up adding index and reviewing the improvement. It’s pain that you have to write one migration file, then migrate it before you could see the improvement, especially when you have tens of FIXME warnings in the log. My tricks is to do experiment part through script/console, and after you get enough information, you could simply add a migration file with a batch of add_index. That would save a lot of time. Below is how I did in one of our projects:

ruby script/console
ActiveRecord::Base.connection.add_index :students, :name
# You could do this through the model class too
Student.connection.add_index :students, :name

From the log, you could see something like this: CREATE INDEX `index_students_on_name` ON `students` (`name`)

And if you want to remove the index:

ruby script/console
ActiveRecord::Base.connection.remove_index :students, :name
# You could do this through the model class too
Student.connection.remove_index :students, :name

From the log, you could see something like this: DROP INDEX `index_students_on_name` ON `students`

After adding the index, you could refresh your web page, and check the log, see if there are still warnings from query-analyzer.

Note that there are 4 types of index:

1. “Normal” Indexes
2. Unique Indexes
3. Primary keys
4. Full-text indexes

The one we talked above is the “Normal” Indexes. I suggest you check this article out for more about indexes.

This is an update to my earlier post about Rails Screencasts .

British Rails developer Eifion Bedford is putting together a collection of Ryan Bates’ free Railscasts series in a text form. This means he is painstakingly transcribing Ryan’s words, putting together screenshots that you can learn from, and code examples that you can copy and paste. This is a great way to consume the material, especially if English is not your first language. The ASCII Casts, as he is calling them, are a great addition to the growing volume of free learning material for Ruby and Rails. I recommend the security series and the performance tips. Thanks to Eifon and his efforts to illuminate the wild world of web development!

Hi guys, I’m writing this to share with you the joy of using ROR with Mysql on Ubuntu 8.10 Desktop Edition.

First, we can get a latest free version of Ubuntu from here. Please choose a desktop edition, because Server Edition is not containing a GUI for us which specializing in host side.

Well, after we have installed the newest Ubuntu, let’s try our ROR with Mysql development enviroment ASAP. The official installing ROR site goes here, or you may need only type several commands as following:

1. Installing RUBY:

 sudo apt-get install ruby-full 

wget http://rubyforge.org/frs/download.php/45905/rubygems-1.3.1.tgz
tar xzvf rubygems-1.3.1.tgz
cd rubygems-1.3.1
sudo ruby setup.rb
sudo ln -s /usr/bin/gem1.8 /usr/bin/gem 

  sudo gem install rails mongrel  

4. Installing MYSQL:

  sudo apt-get install mysql-server mysql-client   

It seemingly worked and I could start my rails projects, but when I tried to rake task, the system was just crashed and came out a result:” !!! The bundled mysql.rb driver has been removed from Rails 2.2. Please install the mysql gem and try again: gem install mysql. rake aborted!”

sudo gem install mysql  

"Building native extensions.  This could take a while...
ERROR:  Error installing mysql:
ERROR: Failed to build gem native extension.
/usr/bin/ruby1.8 extconf.rb install mysql 
*** extconf.rb failed ***
Could not create Makefile due to some reason, probably lack of
necessary libraries and/or headers.  Check the mkmf.log file for more
details.  You may need configuration options."

So let’s correct our step 4 to:

  sudo apt-get install mysql-server mysql-client   libmysql-ruby1.8

Cheers, we can really start our RAILS application now.

Last but not least, to make our default gnome-editor more useful as a programming IDE, we can try to install some plugins into gedit to make it like Textmate On Mac. e.g. there is an excellent project named gmate which included many plugins that we need indeed.

Please let me know when you still have any installing problems with ROR & MYSQL on Ubuntu.