Rails patterns specific to web application - ruby-on-rails

I know about GoF and Rails patterns. But I am dying to learn more about common Rails patterns that apply specifically for web-app. For example, a SignUpPresenter would be great for a form that handle multiple models in one form. It took me about a month to realize this b/c I can't find a good source.
Thank you.

For patterns and anti-patterns I highly recommend Rails AntiPatterns: Best Practice Ruby on Rails Refactoring
It's not all about patterns but you'll discover quite a few of them there. This book is also quite an easy read.

Related

Design Patterns with rails

I'm doing a web application for my Software Enginearing' exam. I decided to use Rails framework and I'm trying to learn it.
During the course we have studied Design Patterns from GoF, but I don't find anything interesting for Rails.
Can anyone adress me to some sources that can help me?
I read this one http://www.amazon.com/Design-Patterns-Ruby-Russ-Olsen/dp/0321490452 and I found it very interesting. Both in terms of design patterns and in the way it goes under the hood of things people usually know about ruby.

Rails learn's confusion

This is a beginner's rails learning confusion. When I learn rails, from time to time, I feel frustrated on rails' principle "Convention over Configuration". Rails uses heavily on conventions. A lot of them are just naming conventions. If I forget a convention, I will either use the wrong naming and get unexpected result or get things magically done but don't understand how. Sometimes, I think of configuration. At least configuration lists everything clearly and nothing is in fog. In rails, there seems a hidden, dark contract between you and the machine. If you follow the contract, you communicate well. But a beginner usually forgets items listed on the contract and this usually leads to confusion.
That's why when I first pick up rails, I feel like it is somehow difficult to learn. Besides, there are many other things that could be new to a learner, such as using git, using plugins from community, using RESTful routing style, using RSpec. All these are new and come together in learning ruby and rails. This definitely adds up difficulties for a beginner.
In contrast, if you learn php, it wouldn't be that bad. You can forget many things and focus on learning php itself. You don't need to learn database handling if you know SQL already(in rails, you need to learn a whole new concept migration), you don't have to learn a new decent unit test(in rails, usually they teach RSpec along the way because rails is agile and you should learn test-driven development in the early learning stage), you don't have to learn a new version control(in rails, you will be taught about git anyway), you don't have to use complicated plugins(in rails, they usually use third-party plugins in textbook examples! what the hell? why not teach how to do a simplified similar thing in rails?), you don't have to worry RESTful style.
All in all, when I learn php, I learn it quick and soon I start to write things myself. Learning php is similar to learning C/java. It tastes like those traditional languages. When I learn rails, it is more difficult. And I need to learn ruby as well (I believe many of you learn ruby just because of rails).
Does anyone have the similar feeling as I have? How do you overcome it and start to master rails? Hints will be welcomed. Thank you.
You do need to learn Ruby. Ruby is a language. It has its own quirks. You don't need to learn a lot of Ruby, but you can't learn no ruby and expect to write anything decent.
Next, you do need to learn the Rails conventions. Learning the conventions means that you don't need to learn the Ruby networking classes. If you don't want to learn the conventions, then writing anything of value will be difficult.
It's really no different than learning C# (as a language), then learning an MVC framework, like ASP.NET MVC, or FubuMVC.
Yes, you throw up a anything in PHP, learning a lot less in the process. But investment is valuable. Your education is valuable.
Learning takes time. Modelling is important, and I've seen some ugly Rails code because the authors were poor modellers. Those poor models turned into ugly databases. But it still worked! It met that customer's needs.
You comparision Rails with PHP does not hold, since Rails is a framework and PHP is a language. You should compare Ruby with PHP, or Rails with some PHP framework (I am not familiar with PHP frameworks and do not know an example)
But you are right about the things that 'magically' happen with Rails. I too had problems understanding them and looked many things in the Rails code to see what was actually happening and why.
To learn Rails you should first learn the language on which it is build (like you should do with any framework IMHO), so learn Ruby first. Personally I liked Mr. Neighborly's Humble Little Ruby Book a lot. It is written in a easy and nice way and is not boring/serious like a lot of books on languages.
After that I read/did all tutorials/guides on http://guides.rubyonrails.org/ they covert the (important!) basics and tell about the Rails specific things you are writing about.
When I first heard of Rails the claim was that you could build a web app ten times faster than the other frameworks. I always thought this was an exaggeration.
Most of the conventions are hard to remember if you don't have ten years of doing it the 'configuration' way. So, for someone new to web development it is hard to remember all the conventions and to understand why they are important. I definitely did not see a ten time increase in productivity. Routing, for example, probably started nice and simple but grew more and more complex. I think some effort should be made (perhaps by the people writing Rails books) to not try and throw every capability out there to confuse newbies.

cakephp or ruby on rails

I've put some of my free time on reading/learning about cakephp but now I'm wondering if will not be better to switch completely to ruby on rails.
Can you give me the good and the bad of those tools, when is about web-development?
many thx
Why switch? Since you've got a head start on CakePHP, take a little break.
Learn some Ruby on Rails for a while, then switch back to CakePHP when the mood strikes you.
That way, in the end, you'll end up knowing two languages/frameworks rather than just one. It's always better to get as much exposure as possible. Each has its benefits and downsides, but why not learn enough to make the decision yourself?
Neither is better than the other. While one may be more suited to particular applications than the other, they are certainly both good frameworks.
PHP is said to be faster, Ruby is objectively a better designed language. These probably make more of a difference than the framework itself - you can always modify the libraries or write your own classes to make the framework do what you want it to.
My advice is to stick with what you know if you are happy with it - learning a new framework is a long process. If you have issues with Cake or you're keen to try something different, Rails is definitely worthwhile.
I recently read a good article from a developer with a CakePHP base who just completed a large Ruby on Rails project.
http://www.jimmycuadra.com/blog/10-from-cake-to-rails
He details where Rails is stronger than Cake but also the other way around. Another blog here compares Ruby and PHP.
http://developingwithstyle.com/articles/2009/06/09/10-reasons-why-ruby-is-better-than-php-reason-5.html
personally i would choose cakephp at this moment. php and mysql are very common on most web hosting packages, even free ones. it is based on php and there is a huge amount of resources to learn and get help from. you can reuse many already written classes.
regarding the speed of cakephp, there are ways how to speed up cakephp in the production environment through the ways you code and caching.
I would choose ruby on rails because
ruby is fun to write
there is a great community
there are more high quality resources like www.railscasts.com and teachmetocode.com

The last 20% in Ruby on Rails

I am (quite) an experienced programmer but totally new to Ruby and Ruby on Rails.
RoR looks great to get working quickly, specially the automatic screen generation for CRUD operations.
It really it gets you productive quickly.
The questions is with the last 20% of the work, when I must finish my application. Won't RoR conventions stand in my way? Because not every database table must be available for all users, and not all users can edit all columns and/or all rows, and the views must be adapted to my site's look and feel, etc.
I understand RoR has been used successfully in live sites, but how exactly do you gain enough speed in RoR to escape gravity after the first phase has been burned out.
I don't think scaffolding gets you 80% there. Scaffolding is nice in that it shows you how the pieces of Rails fit together, but I wouldn't build my application off of scaffolding code. Now that you've been impressed by scaffolding it's best that you forget all about it. :)
Where Rails really shines in my mind is database migrations, the awesomeness of how dynamic ActiveRecord is, and the plugin ecosystem.
There's a lot to learn when deciding to go with Rails. You have a new language, new framework, and new plugins - but if you take the time to learn those things you can be very productive with Rails.
I've been doing ruby on rails for quite sometime. The 80/20 problem is not unique for rails. It applies generally to the entire world. I'm also not aware of any framework that can just do business logic for you.
To answer your specific questions. Conventions will not stand in your way while doing the 20%. Instead, conventions will help you to get through that 20% quicker.
Personally, for user authentication, I use Authlogic. For user authorization, I use Lockdown or Authorization plugin depending on customer need.
I also use inherited_resource in most of my projects to simplify controller code. This is another power of convention.
To increase speed of development, you will not only need to know Rails, but rails gems/plugins that does the right things for you, so you don't have to reinvent the wheels again. Also, knowing Ruby language is a must for quickly develop beyond the 80%.
Ruby Toolbox provides some of the most popular gems and plugins used in typical rails projects targeted at specific domains. You can look through the relevant categories and know what most people use. (And it's probably a good idea to use popular, well maintained gems)
TDD/BDD style development will also help you to speed up in the long run.
Lastly, a warning: If you stray away from rails convention, you will have a painful time in general.
P.S. I used Merb before. My feeling is that conventions helps you in merb, but you won't get too much penalty for not following them in merb. However, my experience with Rails is that if you decide not to follow rails convention while developing rails app, it will come back to bite you in one way or another! So think twice when you really attempted to stray away from rails conventions... (This is from my own experience, and of course subjective, but you can think of it as a warning...)
Won't RoR conventions stand in my way?
Because not every database table must
be available for all users, and not
all users can edit all columns and/or
all rows, and the views must be
adapted to my site's look and feel,
etc.
This is a bit of a non-sequitur. Rails is a framework that has been lifted from real world applications. Those applications had to deal with all those issues also, as well as others you may not have thought of yet. Generally, the conventions make life easier once you learn them.
Another point is that the conventions are merely conventions. You don't have to follow them. You do not even have to use RoR for everything, though I've yet to find a case where I didn't/couldn't, I do generally try to push as much into the DB or cache layers as possible.
I don't believe that you'll ever have a serious problem with Rails conventions. Just stick with the conventions and trust the RoR system. The people behind Rails put a lot of effort into these conventions to support 99% of the common usage scenarios.
If you really need to do something outside the conventions it will eventually get complicated quite fast. However, you are not alone. There are a lots of excellent resources on the net to get help (for example the StackOverflow community).
To sum it up:
Stick with the conventions whenever possible (excellent resource to get started: Rails Guides.
Don't reinvent the wheel. Look for Rails plugins and Ruby Gems instead (don't forget GitHub).
Consult the StackOverflow community if you need something out of the ordinary.
Test all the f***ing time (just for fun).

How does ruby on rails work?

I'm a PHP developer who knows a little bit of Ruby. I want to learn Ruby on Rails, but most of the resources I've come across treat RoR functionality as "magic" -- i.e., it has a certain internal consistency, but don't bother asking how it works in terms of Ruby, MySQL, etc.
Anyway, I want a deep understanding of how RoR works, the design decisions that went into building it, etc. In particular I'm interested in ActiveRecord, but really I'm looking for the whole package.
Any books / sites / advice welcome.
The books "Agile Web Development with Rails" and "The Rails Way" are both pretty good. "Pro Active Record" goes really in depth for Active Record, but doesn't touch on too much else. The podcast Railscasts sometimes just uses the magic, but sometimes it explains what is really going on. Various blogs such as Art of Mission can get into what your looking for.
Additionally, using the ruby-debug gem gives you a much better understanding of what is going on - you can step into what is running behind the scenes.
There are two areas here that can be examined separately:
General concepts (which include design patterns, general attitude principles like DRY and CoC or even agility etc.) since they are the principles behind many design decisions in Rails. Any of these concepts can be studied independently of Rails (since they are general programming concepts). It's good to have at least some understanding of these before digging any deeper. There are many sources about such general principles all over the net (aforementioned Martin Fowler's site is one of the better sources for grasping such concepts).
The way Rails implements these concepts into its corpus. There are, again, two things to have in mind here. Since Rails heavily exploits features of its mother language, it's crucial to understand Ruby's peculiarities (such as mixins and plenty of Ruby's dynamic features). The last thing to understand is how Rails uses these features, ie. how it's broken down into classes and modules, how many of its features are dynamically created on the run and so on. For this purpose, I highly recommend book Ruby for Rails from David A. Black (which is exactly about Ruby, its peculiarities and the way Rails uses them). While this book might be a bit out of date, I think it's still invaluable in its content.
If you really want to know how it works, you can just look at the source code. The online API docs let you see the source code of every method right in the documentation page.
ActiveRecord in Rails is based on Martin Fowler's Active Record pattern. It's basically an ORM (object-relational mapper). It's not even really that sophisticated as far as ORMs go. Java Persistence with Hibernate has a good overview of common ORM concepts.
This one might fit here well too -> http://railsforphp.com/
This is sort of a tangential answer to your question, but I, too, came from PHP development over to Ruby/Rails dev, and it was a big transition for me. As PHP devs, we're used to getting into the nitty-gritty, to to speak, and not being prevented from looking under the hood.
By design, Rails is a black box. You're supposed to learn Rails, almost as a language itself. It's a new way of thinking of web dev, especially from a PHP dev's perspective, though this idea is not uncommon to programming in general.
Not bothering to look under the hood may be the best way to start doing things "the Rails way."
Jamis Buck has a nice series of "Under the Hood" articles on his blog that cover some aspects of Rails' internals.
The "magic" in Rails involves method_missing and the concept of metaprogramming. Dave Thomas of The Pragmatic Programmers created a set of screencasts on metaprogramming Ruby.
PHP has a somewhat-equivalent function called __call, and PHP 5.3 introduced __callstatic. You might take a look at those, as well as search Google for "php metaprogramming", for some reading material on implementing Rails-like behavior in PHP.
I found this site a good starting reference:
http://www.tutorialspoint.com/ruby-on-rails-2.1/index.htm
It assumes MySQL in its examples.
I am sure you can find heaps and heaps by just googling for "ruby on rails tutorials", though.
ruby metaprogramming magic in rails: look at books by Rappin "Professional Rails" and Ediger "Advanced Rails", in addition to Black "Ruby for Rails" mentioned above
Naming conventions are important:
http://rails.wincent.com/wiki/Rails_conventions
http://www.softiesonrails.com/2007/10/18/ruby-101-naming-conventions
If you really want to understand Rails, read the source for the bit of Rails that you want.
/Library/Ruby/Gems/1.8/gems/ on OSX or freeze rails and have access to it in your RAILS_ROOT/vendor/ directory

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