• Git and Ruby Tutorials - a great collection from rubyinside.com, also the comments contain a few good pointers.
• 
  acts_as_dropdown - acts_as_dropdown allows any ActiveRecord class to be easily used as the contents of a HTML select tag.
• Handling JavaScript Events on Multiple Elements - proper JS/Prototype event handling!
• tranexp - Dr. Nic in action again. This time it’s a dead simple translator gem.

Update: Sergio, the author of the livevalidation rails plugin updated the plugin so you can disregard the finale of the article (validatesconfirmationof is working, as well as the newest version of livevalidation, 1.3 is used in the plugin - so no additional tweaking is needed, install and validate away )

Surely I am not the only one who was a ‘bit nervous’ (that was a mild euphemism) when his carefully entered data disappeared after submitting a form to the server. Nowadays web applications are doing better than that - valid data is saved and only the problematic fields are pointed out.

Of course even that feels so 1990’s now. A contemporary (ehm… web 2.0?) web application is expected to validate the form on the client side already (WARNING! That doesn’t mean at all you shouldn’t validate on the server side though - client side validation is for the good guys but you should still look out for the script kiddies et al), pointing out the errors on the fly so there is no need to come back and change/edit those fields after submitting a form.

My library of choice is livevalidation, which has a Rails companion too - if you are using Rails form helpers and standard validation on your models, you don’t have to touch anything just install livevalidation (=drop it to your javascripts folder, it’s a single .js file). w00t!

The only major shortcoming (from my POV) of the Rails plugin is that validatesconfirmationof is not implemented. However, it’s easy to add it via standard javascript:

<input id="user_password" name="user[password]" size="30" type="password" />
<input id="user_password_confirmation" name="user[password_confirmation]" size="30"> 
<script type="text/javascript">
var validate = new LiveValidation('user_password_confirmation');
validate.add( Validate.Confirmation, { match: 'user_password' } );
</script>

That’s it!

One more note: the Rails plugin contains version 1.2 but there is a newer version, 1.3 so be sure to replace it.

In my quest to whip my feed reader’s Ruby/Rails related content into shape a bit, I made a little research to find out which Ruby/Rails blogs are the most popular at the moment. I had given up on following most of the blogs systematically a long time ago - it is becoming increasingly hard to keep track of even the aggregators, not to talk about the blogs themselves. There are hundreds of Ruby/Rails blogs out there right now (I am talking about the ones found on the few most popular aggregators - in reality there must be much more of them), so it is clear that you need to pick carefully - unless you happen to be a well-paid, full time Ruby/Rails blog reader (in which case you still would have to crank a lot to do your work properly).

OK, enough nonsense for today - let’s see the results counting down from the 10th place! If you are interested in the method they were created with, or a longer, top 30 list from technorati and alexa, check out this blog entry.

10. http://weblog.jamisbuck.org/ by Jamis Buck.

Jamis Buck “is a software developer who has the good fortune to be both employed by 37signals and counted among those who maintain the Ruby on Rails web framework”. He is mostly blogging about (surprise, surprise!) Rails - of course on a very high level, which could be expected from a Rails core developer. Very insightful posts on ActiveRecord, Capistrano and other essential Rails topics delivered in a professional way.

9. http://weblog.rubyonrails.org by the Rails core team

This is the “default” Ruby on Rails blog, used for announcements, sightings, manuals and whatever else the RoR team finds interesting .

8. http://www.slash7.com by Amy Hoy.

This is a really cool little site - Amy is a very gifted writer and designer, publishing very insightful articles as well as the nicest (hands down!) cheat sheets about different Web2.0, Ajax, Rails and that sort of stuff. Definitely worth checking out!

7. http://errtheblog.com by PJ Hyett and Chris Wanstrath.

A very serious blog of two Rails-geeks about advanced topics (but very well explained - so if you are not totally green (#00FF00) you should do fine). Among other things, they have contributed Sexy Migrations to Rails recently.

6. http://nubyonrails.com/ by Geoffrey Grosenbach

Geoffrey is the author of more than twenty of Rails plugins, (including gruff, my favorite graph drawing gem), a horde of professional-quality articles and the PeepCode screencast site. Do I need to say more?!

5. http://redhanded.hobix.com/ by _why the lucky stiff.

_why is probably the most interesting guy in the Ruby community. He is the author of (among tons of other things) Why’s Poignant Guide to Ruby, HPricot, the coolest Ruby HTML parser, Try Ruby! (a must see!) and Hackety Hack, for aspiring wannabe programmers who want to hack like in the movies! The list goes on and on… This guy never stops. If someone will ever invent the perpetuum mobile, he will be it (in Ruby, of course).

4.http://hivelogic.com/ by Dan Benjamin.

Dan’s recent work include Cork’d, a web2.0 wine community site or the A List Apart publishing system. He does great podcasts with various guys.

3. http://mephistoblog.com/ by Rick Olson and Justin Palmer

Personally I was quite surprised that a blog concentrating on such a narrow topic (in this case the mephisto blogging system) could grab the 3rd place - so I have checked both alexa and technorati by hand just to be sure, and it seems that everything is OK - mephistoblog is ranked very high on both of them, justifying this position. After all, mephisto is the leading blog system of Rails!

2. http://www.rubyinside.com/ by Peter Cooper.

This blog is my absolute favorite from this top 10 list (actually, from all the Ruby blogs I have encountered so far). I am definitely with Amy Hoy, who said If you had to subscribe to just one Ruby blog, it should be this one. If you would like to know what’s happening in the Ruby/Rails community, rubyinside is the place to check. If there is no new post here, it’s because most probably nothing happened!

And the winner is: http://www.loudthinking.com/ by David Heinemeier Hansson.

Well, what should I add? David is the author of Ruby on Rails, so no wonder his blog topped the list!

Conclusion
It’s interesting to note that nearly all the blogs listed here are mostly pure Rails ones - rubyinside (mixed Ruby/Rails) and redhanded (pure Ruby) being the two exceptions. It would be interesting to generate such a list for Ruby blogs - though I am not sure how. The sources I have used (most notably rubycorner) aggregate both Ruby and Rails blogs) - so it seems there are much more Rails bloggers out there (or they are much better (with the exception of _why) than the Ruby bloggers).

I would really like to hear your opinion on this little experiment - whether you think it makes sense or it is completely off, how could it be improved in the future, what features could be added etc. If I’ll receive some positive feedback, I think I will work on the algorithm a bit more, and run it once in say every 3 months to see what’s happening around the Ruby/Rails blogosphere. Let me know what do you think!

If I had to choose the single most not-really-well-understood, mystified, unsuccessfully demystified, explained and still not-really-grasped topic in the Rails world (and beyond), my vote would definitely go to REST. It seems to me that there are two types of people in the world: those who don’t get REST (and they think it’s a basic postulate to rocket science explained through quantum theory) and those who get it, and don’t understand the former group (unless they are coming from there, that is).
I have been playing around with RESTful Rails recently. Below is my collection or Rails REST howtos, tutorials and other resources I have found so far and which were adequate for my transition from the first group to the second .

You should definitely begin with REST 101 - then check out the other stuff as well!

• REST 101 by Softies on Rails
  • Understanding Resources
  • A Million APIs
  • RESTful Design
  • Routing
  • Respond!
• RESTful Rails Development
• A great PeepCode screencast: RESTful Rails
• A nice REST cheatsheet
• A presentation on REST and ActiveResource

Please leave a comment if you know some more (just for completeness’ sake - I think the above resources should be enough to grasp RESTful Rails both theoretically and practically.

Though dreamhost offers phpBB as one of their one-click install goodies (ergo it is the easiest to install of all forums since you almost don’t have to do anything), I have been looking for something different. To me, phpBB’s interface was always quite unintuitive and too heavy - I wanted something smaller, easier, more compact. The problem was I did not know what should I search for - until I came across beast, a lightweight forum written in Ruby on Rails. It was love at the first sight!

When it comes to tools I am using, I am really language agnostic - this very blog uses WordPress (PHP), I am using Trac (Python) to track my projects, mediaWiki (PHP) is my preferred wiki etc - so even if it may seem so, I did not choose beast because it is written in Rails (although +1 for that ), but because of the design and ease of use. My first thought after trying it was ‘wow, this is as easy to use as a 37signals app’ - it’s really that intuitive and well designed!

Well, this sounds fine and all, but installation on dreamhost was a different story. Thanks God I have found a superb, step by step HOWTO here. However, even after following all the steps, I got ‘incomplete headers’ and other problems, which I have managed to fix - here are some additional comments to the HOWTO:

6. You can forget about this point; as the HOWTO says, it is already installed on DH and it will work without any problems.
7. Forget about ‘development’ and ‘test’, however be sure to get ‘production’ right, as the next step will not work otherwise. It should look something like this:

production:
  adapter: mysql
  database: beast_prod
  host: mysql.myhost.com
  username: us3r
  password: p4ss
  port: 3306

ENV[‘RAILS_ENV’] = ‘production’

Now you should apply the ‘GetText patch’ - it can be found later in the thread. After you should be up and running!

After playing around, I have found that the user listing is not working - fortunately I have found this as well in the forum. The solution is:
app/views/users/index.rhtml line 3 should be modified to

%lt;% form_tag '', :method => 'get' do -%>

I have just finished reading Ruby for Rails: Ruby techniques for rails developers from David A. Black. Here is my (WARNING: highly opiniated) review…

I have been a Python fanatic for quite some time, and decided to give Ruby a shot. After some googling, I found most references pointing to a book called the ‘Pickaxe’. Quite a strange name for a programming book, thought to myself, but picked it up nevertheless. I have been instantly converted after a few dozen pages - mining Ruby with the pickaxe was an awesome experience! Since then, I have finished reading the second edition and became a Ruby enthusiast.

After lurking around a bit, I have learned that the common standpoint is that every newcomer/beginner should grab a copy of the Pickaxe to get started. Based on my previous, positive experience I could not agree more - until I came across R4R.

Ruby for Rails is awesome: The technical depth is just right to not distract beginners, yet detailed enough for even the more advanced readers. I did not skip a single page (though years of programming experience and tons of similar programming books I came across during that time could allow me) and finished reading it in no time.

I could write some more about how cool this book is (and it would deserve every bit of it), but I think you can read about that just anywhere (a nice review can be found here), so I would like to point out something different: If we consider the Pickaxe THE book for newcomers, then IMHO R4R is a Pickaxe killer.

Don’t get me wrong: I am a great fan of the Pickaxe, which is another very high-quality technical book - but if someone wants to apply the ‘right tools for the right job’ principle, I think newcomers who already decided to learn Ruby should grab Ruby for Rails. Programming Ruby’s Part I is absolutely well suited to get the ‘feeling’ of Ruby, and it’s next chapters are great to learn the advanced stuff - however in my opinion, the leap between the first and the next chapters is too big for an absolute beginner. Ruby for Rails is there to fill this gap.

Maybe someone might not advice this book to a newbie eager to learn Ruby, since it has ‘Rails’ in it’s title. However, R4R is still primarily a Ruby book, and while I found the Rails parts to be very helpful, I can recommend it to anyone who would not like to learn Rails at all - though the full potential of the book comes through if one would like to learn both.

Conclusion: Ruby for Rails is an awesome book on Ruby. If you are beginner, would like to get a solid understanding of the Ruby principles, or your goal is to polish up your Ruby knowledge to grasp the Rails framework - R4R was made just for you! Check it out - you won’t be disappointed.

I am planning to write a series of entries on screen scraping, automated Web navigation, deep Web mining, wrapper generation, screen scraping from Rails with Ajax and possibly more, depending on my time and your feedback. Since these entries are going to be longer, I will be posting them to separate pages, and announce them on my blog.

The first article is ready, you can read it here.

It is an introduction to screen scraping/Web extraction with Ruby, evaluation of the tools along with installation instructions and examples.

Feedback would be appreciated (leave your comment here/on the article page, or send me a mail at peter@[name of this site].com), I will update/extend the document and publish new ones based on your feedback.

Programming is great fun (mainly with Ruby . However, this statement does not contradict with the fact that sometimes programming can be also hard. I came across a nice site today which can offer some help in these moments: Programming is hard. Judging from the size of Ruby/Rails/ActiveRecord tags (there is even a script.aculo.us tag!) it seems that it has a nice dose of Ruby/Rails stuff - solutions for common problems and also links to tutorials, frequenty asked nuby questions etc. Be sure to check it out!

Just two weeks after Ruby on Rails was featured in the prominent Dr Dobb’s Journal, it gets into the limelight again, in even greater power than before: Guess who is staring at you from the frontpage of Linux Journal? Yes, it’s DHH… and the reason? The current issue is full of Ruby and Rails articles, tips and tricks etc. Read the full story at David’s blog.

In my previous post on migrations i wrote that “…they are not covered in any of the basic books on RoR”. Well, this statement does not hold anymore, since Agile Web Development with Rails, 2nd ed. is already creating the models with migrations.

While the last part of the post (why are migrations so cool) is still up-to-date, they way of creating migrations is different from 1.1 on, so i have decided to review the topic and add some new points, too.

Migrations are now created automatically with the model

In my previous post, i have been creating the migration manually with the command

ruby script/generate migration ProductMigration

However, as of Rails 1.1, you don’t have to do this anymore. When you generate the model (let’s stick with the Product model as an example) the migration is automatically generated:

ruby script/generate model Product
...
... #some lines omited
...
create db/migrate/001_create_products.rb

Now you can edit the file db/migrate/001createproducts.rb to contain something like this:

class ProductMigration < ActiveRecord::Migration
def self.up
create_table :products do |table|
table.column :title,       :string
table.column :description, :text
table.column :image_url,   :string end
(rest of the file omited)

Then run

rake db:migrate

To update the database. That’s even easier than in the previous versions of rails!

Valid column data types and possible options

Valid columns are:

integer, float, datetime, date, timestamp, time, text, string, binary and boolean.

Valid column options:

• limit ( :limit => “50” )
• default (:default => “blah” )
• null (:null => false implies NOT NULL)

string is the equivalent of varchar(255), so if you would like to have a string column (called title) of length 100 instead of 255, with default value ‘Some title’ and to forbid NULL value, you have to type

table.column :title,
:string,
:limit   => 100,
:default => "Some title",
:null    => false

Generating test data

I am quite sure you know the situation when you want to test something quickly and you waste precious time to generate some test data, which you trash after the testing just to find yourself in the same situation later?

Well, migrations can help you to prevent headaches because of this, too. Here is how:

ruby script/generate migration create_test_data
Create db/migrate/002_create_test_data.rb

You can create test data inside the migration file like this:

class ProductMigration < ActiveRecord::Migration
def self.up
Product.create(:title => ‘My cool book about the meaning of life’,
:description => ‘42′,
:image_url => /images/cool_book42.png)

You can now commit this migration to the RCS you are using, and modify/add more test data later.

The other advantage is that your colleagues won’t spend time writing dummy test data either: they can just check out this migration and happily use the provided tests.

If this is still not enough for you…

You can write SQL statements inside the migrations. For example:

execute "alter table items
add constraint fk_items_products
foreign key (product_id) references products(id)"

However, use this with care since you have to write native DDL statements, which violates one of the fundamental ‘cool factors’ of migrations: independence from DB vendors.

Conclusion

The Agile Web Development with Rails, 2nd ed can be considered as the Rails bible and since it is promoting migrations as the definitive way to handle your DB issues, i think migrations will become (in fact the already did for lots of people) the state of the art. After using them for a while and enjoying the power and flexibility they provide without having significant drawbacks, i don’t really see why should one not use them in the future.

As I wrote in my previous post, I am currently reading/coding the depot example from the Agile Web Development with Rails book. I had one unclear issue so far - maybe someone can help me to find it out: I did something wrong or this is really a typo in the book?

Putting sessions in the database According to the book, this should be done with

rake db:session:create

However, after entering this command to the console I got:

(in /home/peter/development/src/railsprojects/depot)
rake aborted!
Don't know how to build task 'db:session:create'

After some playing with rake –help, I have found the –tasks switch:

rake --tasks

and here I have finally found the remedy for my problem: the correct command is

rake db:sessions:create

(note the additional ’s’ character) Is this because my rake version is too old/too new or this is a typo in the book?

After this modification everything worked again as intended.

I have bought both books recently. Maybe it is a little bit early to write a review since I am through just a few chapters in both, I have been so impressed that I had to write a (not so) short entry at least ! I have been using C++/Java/Python for years, and have been reading as much books on every possible aspect of development with these languages as I could get. In my oppinion Ruby and Rails are absolutely superior to all of these languages (and their web frameworks/related things) in this context - The Pickaxe, AWDwR and R4R cover nearly all the things you will ever need to learn the language and Rails - and not just understand the ‘how’, but also the ‘why’, learn best practices, coding and development methodologies from code style to design issues, related technologies and more.

The point is not (only) this, since you can do the same with a few Java books (although not 3, but something like 10), however you will have harder time with Python (There is a Django book on the way, and also the Turbogears guys are publishing one but neither are out yet - but no PickAxe, AFAIK) - however, the point is, based on the experiences i have had with C++/Java/Python books that neither of them are so well written/to the point/effectively explained/well built up than the Ruby ones. Simply put: The Ruby/Rails books are the best technical books i have ever read on programming and (web) development.

Agile Web Development with Rails, Second Edition I begun to develop the depot application with the first edition about a month ago, and since I was new to both Ruby and Rails, I have thought: WOW! I was about halfway through the depot chapter when i have noticed the announcement about the Second Edition a few days ago. I have purchased the pdf version immediately, and I am quite sure this purchase has to be listed in my ‘Best value for money TOP 10′ list (along with R4R . It was a very refreshing experience to code the depot application from the first edition, but as I got into Rails more and more, I have felt that there are some small gaps here and there. On the mailing list, everybody was talking about migrations (i had no clue that time about them), helpers, AJAX/RJS, REST and other stuff i was not able to find during the depot development, and though the amount of information and level of coolness was overwhelming, I still sensed there is still even more than this. After redoing the depot application with the second edition, all these things (among others) are finally there! You get all the goodies from the very beginning (migrations, writing your own helpers, AJAX etc) so you do not have to search the Web for the newest features anymore.My overall impression was that the small annoying things are gone, the good things are even better, thus the overall experience of reading the book/following the code is even more delightful! I can’t wait for the next chapters! This upgrade definitely rocks! Well done Dave et al.

Ruby for Rails Ruby techniques for Rails developers I have gone through just the firs three chapters so far, and though they are supposed to be introductory chapters (entitled How Ruby works, How Rails works and Ruby-informed Rails development) I could not believe how much info I got out of them. I have to say that I am a totally mega-n00b to both Ruby and Rails, but still, I have gone through the PickAxe and half of AWDwR, 1st ed, i am a regular reader of Ruby-talk and the RoR mailing lists, so on the other hand I have some basics, and still these chapters provided me a lot of new insight. The book (or at least the first three chapters) is extremely well written, easy to grasp yet the breadth of knowledge is really impressive. It really shows the design philosophy, logics, inner working of the things rather than just providing some theory with a few examples, or being a ‘yet another Ruby/Rails book’ in any way. If you would like to find out how the things really work, and why they work that way, rather than just be a developer who can do this and that with Rails, definitely check this book out!

There was a kind of flamewar on the Ruby on Rails mailing list about the pricing of the AWDwR second edition: One group argued that they should get some discount because they own the first edition, and the other party did not agree with this standpoint. Well, personally I am definitely in the second group - I did not hesitate to buy the PDF for a moment - I can understand (but not support in any way) the arguments of the first group, but I would gladly pay for this book even $100, not $20+, regardless of the editions I own. (And just FYI, I am a full time Java developer and though I would like to get a Ruby (on Rails) job ASAP, due to different constraints RoR is and will be just my hobby for some time)

Just my 2c.

Although migrations are a very cool feature of Ruby on Rails, they are not covered in any of the basic books on RoR i have encountered so far (Agile Web Development with Rails, Ruby for Rails Programmers).

Update: Check out my recent post: Ruby on Rails Migrations: Reloaded for an update.

Both these books are using an ‘in medias res’ style approach - they guide the reader through the essential features of Rails by building a web app from scratch. The models in the examples are creaed in SQL rather than with migrations. Let’s examine the difference on a simple example, taken from AWDwR. (Further I am assuming that you have generated a rails application, a development database for the application and the DB connection settings (database.yaml) are correct.)

The classic way: SQL DDL

Create the sql file, create.sql:

drop table if exists products;
create table products (
id           int            not null auto_increment,
title        varchar(100)   not null,
description  text           not null,
image_url    varchar(200)   not null,
price        decimal(10,2)  not null,
primary key (id)
);

After this, you can create the table with:

mysql name_of_your_DB < create.sql

You are now ready to generate your model.

Doing the same with migrations

In your rails app directory, issue the following command:

ruby script/generate migration ProductMigration

then open the file db/migrate/001productmigration.rb and edit it. To achieve the same result as in the SQL example, the file should look like this:

class ProductMigration < ActiveRecord::Migration

def self.up create_table :products do |table|

table.column :title,
:string,
:limit => 100,
:null => false

table.column :description,
:text,
:null => false

table.column :image_url,
:string,
:limit => 200,
:null => false

table.column :price,
:float,
:null => false
end
end

def self.down
drop_table :products
end
end

Run the migration wit the following command:

rake migrate [VERSION=version_number]

And you achieved the same result as with the first method!

That’s very nice, but…

Well, if the only purpose of migrations would be solely the possibility to write Ruby code instead of SQL, even this would be enough for me to go for them. However, i have to admit that this alone would be a rather feeble argument. The good news is that it is not! There is much more to migrations than writing Ruby code:

• Migrations are DB agnostic - The ‘write once, use everywhere’ principle really works here!
• You don’t have to think about obscure SQL specific things anymore - let Rails handle them for you! (OK there are some really complicated things, but fortunately they are adressed by some great books like Rails Recipes, code snippets like Migrate Plus, and I believe that by the Rails team, too.)
• You can change the database as much as you want, and the data you have already there is not affected.
• You get very effective versioning: track changes, concurrent versions, upgrade/downgrade your schemas easily!
• You can generate DB schemas from migrations.
• And possibly much much more… I am a newbie too!

In my oppinion, judging based on the Rails mailing list discussions, migrations are accepted more and more as the definitve way of creating, maintaining, versioning your DB models - so everybody considering serious Rails development should give them a look!

About a month or so ago, we begun to work on a new ruby puzzle site entitled rubychallenge.com with Alex Combas.

Some people may think after reading this line: “Yet another ‘not pron’ or ‘pythonchallenge.com’ clone”. Well, i would not say we did not borrow some basic concepts from these great puzzle sites, but our final product will have not very much in common with them: There will be programming puzzles on rubychallenge.com, and the domain suffix is equal with that of the pythonchallenge site. However, the analogy stops here. Rubychallenge will offer an entirely different programming/game/puzzle experience compared to all the similar sites out there, both in terms of game concepts and mechanics, as well as entirely unique site structure/design.

We have tons of ideas in our wiki already, and right now we are fledging out which ones to implement. Alex just set up a working development environment, so after ironing out some ideas crucial to begin, we might even write some code soon We would like to come up with a presentation/demo page as soon as possible, and possibly a development blog to inform you what’s going on. At some point we would like to incorporate some beta testers, so stay tuned!

Being a professional Java programmer myself, i collected some links that might bridge the gap for Java programmers who would like to take a peek at Ruby:

Introductory materials

• 10 Things Every Java Programmer Should Know About Ruby If you plan to read just one document of this list, choose this one!

• An Introduction to Ruby for Java Programmers Another nice introduction from Jim

• Coming to Ruby from Java The name says all

Java - Ruby integration

• JRuby - A 1.8.2 compatible Ruby interpreter written in 100% pure Java. Charles Oliver Nutter, one of the JRuby developers in a discussion claimed that “We’re currently working to make JRuby more EJB and J2EE-friendly, so you’re certain to see more of these opportunities.”

• Calling All EJBs — From Ruby? Ideas on EJB-Ruby integration

The question from the top of every RoR/Java FAQ:

• It’s boring to scale with Ruby on Rails, says DHH
• IBM poop heads say LAMP users need to ‘grow up’ Nice article on the LAMP stack in general (i.e. not just Ruby on Rails)
• Does Ruby on Rails scale? A clear and definitive answer

Ajax Goodies:

Not exactly java, but nice Rails+Ajax technology showoff

• http://script.aculo.us
• http://script.spinelz.org