I'm about to begin a Ruby on Rails project and I'd love to hear how others go through the process of starting an application design. I have quite a bit of experience with RoR, but don't have that many starting from scratch with only a vision experiences and would appreciate the wisdom of others who've been there.
I'm looking for an order of events, reasons for the order, and maybe why each part is important. I can think of a few starting points, but I'm not sure where it's best to begin
Model design and relationships (entities, how they relate, and their attributes)
Think of user use-cases (or story-boards) and implement the minimum to get these done
Create Model unit-tests then create the necessary migrations and AR models to get the tests to pass
Hack out the most basic version of the simplest part of your application and go from there
Start with a template for a rails app (like http://github.com/thoughtbot/suspenders)
Do the boring gruntwork first (User auth, session management, ...)
...
I found myself looping the following tasks for most projects:
Gather User requirements
Design database Models
Build Views
Streamline Layouts
Find and learn Plug-ins/Gems
Testing
User Review/Acceptance
Deploy the app
Documentation
After these years of working as a freelancer, I think step 1 and 2 are the most important (at least for small projects). Before writing any code, I urge users to finalize all UI first. HTML skeleton is better than written document. Users do not and will not understand software specifications. They can only give feedback after they see can click something. So being fluent in building a HTML site is a helpful skill. Sometimes I delegate the task to a partner, as a SA role.
Rails is very good for building an ever-evolving schema. Try to use migrations and data seeding instead of writing SQL statements directly. I find myself rely on ActiveRecord more and more overtime. The script/console is a nice tool to test out those many-to-many relationships and building :conditions =>.
I worked on a few legacy database lately, the establish_connection and set_table_name feature in ActiveRecord glue old and new database elegantly.
I'd also like to use this chance to thank Ryan Bates, I learn a lot of Rails from his railscasts.
Related
I am new to ruby on rails and I am working on a web application written by ruby on rails. It has more than 10 models and I need to add some new attributes to some of the models as well as new methods and views. I also will need to remove or enhance some of the functionality. I know that I would need to generate new migrations and from there add/remove new columns. Then in controllers, add/modify methods, and update the views.
I wanted to know what would be the best steps (and in which order) for doing the above tasks. Also, do I need to change other files in folders like test or any other folder? What things should I consider to minimize the troubles later?
Thanks in Advance.
Since you are new to rails, the first thing you should do is to read through the getting started guide. This will help you understand the fundamentals of the rails framework and the application you inherited. After that, there are several other guides worth reading (from the same site) that may be directly applicable to the work you are doing.
Another incredibly helpful resource is railscasts. Some of these are outdated, but they are still a great starting place and can help introduce you to both new, powerful gems and rails techniques to get the work done faster and better.
As to your specific question, rails is built on an MVC architecture (meaning Model Views Controllers). It is in your best interest to try and follow this practice whenever possible. Reading up on this will clarify some of your questions as well.
When you run a migration, you will be modifying your database. The changes are viewable in the database schema (which should never be modified by hand, always modify it through migrations). This will add attributes to your models whose table you modified. In the controllers, you will add logic to deal with all of these things and the views will present the data to your users (or allow users to enter data). Asking which order is best is probably rather opinion based, but I would say you should modify the tables (run needed migrations) first. This way you can then generate the logic to deal with the new attributes. I would then create the controller logic and finally the views.
You also ask what other files need to be changed. This is heavily dependent on your system. At a base level, you should definitely be writing tests to support the logic you are generating (and many developers will advocate that you should do this before you write the other logic, a process called Test Driven Development).
TL;DR: Read the guides, work through a basic tutorial, and watch some Railscasts. This should get you up to speed on the process and best practices that go along with rails development.
Perhaps a stupid question, and without code, so I'm not sure I'm on the right StackExchange site. If so, sorry and give me a comment please.
I begin programming in Sinatra (only intranet until now) and in the samples they almost always use migration with activerecord, the same with RoR.
I have experience enough with activerecord itself and it is very helpfull but I'm not sure why migration is always used ? If I create a project I just create a SQL script or a Ruby activerecord script that does the creation of the DB for me and that's it..
If I need the site or script somewhere else I just need to execute that script and ready.
Obviously I'm missing here a lot, so who can me explain the other benefits or point me to a good explanation ?
From Rails docs:
Migrations are a convenient way to alter your database schema over
time in a consistent and easy way. They use a Ruby DSL so that you
don't have to write SQL by hand, allowing your schema and changes to
be database independent.
So, the main two benefits are:
It's like Git for db schema, you won't know how that's useful until you are in a mid-size or big project with many contributors and someone makes a bobo :)
You write ruby code to build your db schema, this way if you decide to move from mysql to pg for example, you don't need to open up pg manual and check code compatibility
Update
In the api docs of migrations, you will find many nice use cases (to be honest i didn't know about half of them) ... check it out (http://api.rubyonrails.org/classes/ActiveRecord/Migration.html)
Building a creation script for your database is great, provided two things:
All your database deployments are on new machines
You get your database schema exactly right the first time
In our modern agile environment we not only don't believe it is possible for a project larger than a few lines of code, we also don't encourage aspiring to it.
Active Record's Migrations offer a way to describe your database incrementally. Each "migration" defines how to add its features to the database ("upgrade"), and how to remove them if necessary ("downgrade").
When running migrations, on top of actually running the scripts, Active Record also maintains its own table (schema_migrations), to remember which migrations have been applied to the database, and which are pending.
This enables you to build your database alongside the features as you develop them. It also facilitates working in teams, since each team member develops her own migrations, and Active Record "stitches" everything together, so you don't have to maintain a monolithic creation script.
When developing a Rails app with a legacy schema that is in-use by an existing application, if tables have NOT NULL constraints on foreign id columns throughout the schema, in order to create/save models for tests, models need to exist for those associations, and their associations, etc. So, it isn't an easy as just creating one model at a time as you need it and testing with it.
As far as testing goes, this seems to be a problem if you are using FactoryGirl and want to create and save model instances to return from controllers, etc. when all of the association dependencies are involved. Another option is to mock, but mocking can be a little more time consuming and it doesn't allow you to do integration testing as easily. Another is to use fixtures, but those are time consuming and brittle. Another is to pre-populate the test database with production data, but that doesn't solve the need for factories, etc./known data to expect in tests, and Rails usually expects to start with a clean DB for the test environment.
What strategies for developing models, tests, etc. do you use when you have an existing complex schema that you are bolting a Rails app onto- not just for reading data, but also writing to the existing schema that is in use by an existing production application? (i.e. the "rebuild the ship while at sea" problem)
When we first started out on this problem, I was looking for something that could autogenerate models from the existing schema. I found Dr. Nic's magic model generator, but it only stated that worked in Rails 2.x. I got a Rails 2.x environment running (forget the specific version it worked in) but it didn't seem to help much, so I wrote a script to generate our models. However, when we started development we then had a load of models, so we started to try to move out the ones we didn't need, then needed to comment out associations to models that were no longer there, but some of those were required/NOT NULL foreign keys, so we're now having to move them back in and uncomment those more than we thought we would.
We did write and uncover some things that were helpful during the process, not all of which we've used, but they might be helpful to others:
https://github.com/influitive/apartment
https://github.com/karledurante/secondbase
https://github.com/drnic/composite_primary_keys
https://github.com/garysweaver/activerecord-define_nils
https://github.com/garysweaver/activerecord-native_db_types_override
https://github.com/garysweaver/modelist
https://github.com/garysweaver/stepford
https://github.com/garysweaver/structure_sql_to_migration
As for test data setup, I started writing a tool to automate the development of FactoryGirl factories called Stepford and wrote Modelist to help us test models, resolve circular dependencies, and identify model dependencies, so we don't have to include all automatically generated models.
So far really, the only answer I've come up with and have heard other say also is that rebuilding an existing application, even piecemeal, with different technologies is difficult, slow, and error-prone.
Im taking on an upcoming project that involved creating and managine a large complex mysql database using RoR. It involved, many table, deep foreign keys, many to many, etc.
Anyone know a good resource (book, website, etc.) which can help me learn how to do it? I need a clearer understanding of migrations and how rails handles relational databases.
Any suggestions?
railscasts.com is great. He talks a lot about setting up your typical HABTM relations polymorphic associations, inner nestings you name it. and Bates makes it extra easy to understand.
Past that I would definately try to start off on the right food using the Metrics gem to monitor database and CPU usage. Always ensuring you're making the lightest touch on the db.
Besides RailsCast, I would recommend RailsLab: Scaling Rails which focus on large Rails application. It seems doesn't update recently, but the post still useful, not only database, but also memory, performance etc.
+1 for Railscasts.com suggestion from Trip. I've gotten a ton out of those since I moved to Ruby and Rails from ColdFusion. I also like the book "The Rails 3 Way" from Obie Fernandez. It has an extensive ActiveRecord section that is very informative both for new Rails users and is a great reference. Another solid one is "Rails 3 In Action" from Ryan BIgg and Yehuda Katz.
You can check out books at the Pragmatic Programmers website. Probably one of the best options is: Agile Web Development with Rails
I also found Ruby on Rails Tutorial to be a good resource.
Also be sure to look at the Rails Guides They are well written and cover many topics in depth. For example, the migrations you mentioned and many to many associations You can even download them for offline use. Here is an answer about how to do that here
Code School have some great interactive courses such as Rails for Zombies.
I wanted to make a web site with the following basic features- (1)User registration for buyers and sellers. (2)profile pages (3)A buyer should be able to post work and should get profile links of the corresponding seller who has expertise in that work.
As time progresses i would want to add more features to the site.The freelancer sites where user can post jobs and get bids is the best example of the work.
(1)I want my code to be maintainable as i woud be adding features later on. (2)It should be quick to develop. (3)Resources should be available(not the entire thing, atleast in bits and pieces) for the above requirements and should not be tough to find for future enhancements. (4)Design should be decoupled from the buisness logic as i would outsource the design work.
I was thinking of Ruby on Rails for this work as i have experience in the MVC model and RoR looks cool.I am from the mobility domain so i don't know whether RoR will suit my work
Would RoR suit this purpose.If yes where can i find the resources to the above mentioned requirements.
Thanks
Ruby on Rails would be ideal for this type of website.
Check out some of these resources for info on how to use Ruby on Rails:
http://guides.rubyonrails.org/
http://railscasts.com/
http://www.railsforum.com/
I noticed you are already aware of TeachMeToCode, but there is a tag there for all the Rails 3 tutorials, with some blog tutorials and what looks like the beginning of a series on how to build a del.icio.us clone. Since they are in Rails 3, they would be well worth checking out:
http://teachmetocode.com/screencasts/tag/rails-3/
One of the best tutorials:
http://railsforzombies.org
It will let you have your own point of view quickly.
It depends on with which languages you have experience. Any good MVC framework will do the job just fine but if you like Ruby syntax RoR is definitely a good framework to develop this kind of application.