How do I generate a random number between 0 and n?

I ran into an issue in my Rails 4 app while trying to organize JS files "the rails way". They were previously scattered across different views. I organized them into separate files and compile them ...

Before anything, please note that I have found several similar questions on Stack Overflow and articles all over the web, but none of those helped me fix my issue: PG Error could not connect to server:...

The default Rails 4 project generator now creates the directory "concerns" under controllers and models. I have found some explanations about how to use routing concerns, but nothing about controllers ...

A user has many uploads. I want to add a column to the uploads table that references the user. What should the migration look like? Here is what I have. I'm not sure if I should use (1) :user_id, :...

There's a strange issue with Rails 4 on Heroku. When images are compiled they have hashes added to them, yet the reference to those files from within CSS don't have the proper name adjusted. Here's ...

Where can I find a list of data types that can be used in Ruby on Rails 4? Such as text string integer float date I keep learning about new ones and I'd love to have a list I could easily ...

Im trying to install an open source rails 3.2.21 application that uses the mysql2 gem, but when i try and run the bundle commant I get the following error: Fetching: mysql2-0.3.18.gem (100%) Building ...

I'm setting Rails 4 application with Ruby 2.0, but I'm getting "Web application could not be started" and get this trace: cannot load such file -- bundler/setup (LoadError) /usr/local/lib/ruby/...

In rails >4.0.0 generators creates CRUD operations with before_action not before_filter. It seems to do the same thing. So what's the difference between these two?

Is there an alternative to update_attributes that does not save the record? So I could do something like: @car = Car.new(:make => 'GMC') #other processing @car.update_attributes(:model => '...

I created a Rails application, using Rails 4.1, from scratch and I am facing a strange problem that I am not able to solve. Every time I try to deploy my application on Heroku I get an error 500: ...

I just installed Rails 4.0.2 and when creating a new app, in the bundle stage I get: Installing pg (0.17.1) Gem::Installer::ExtensionBuildError: ERROR: Failed to build gem native extension. /Users/...

I have a Release model with medium and country columns (among others). There should not be releases that share identical medium/country combinations. How would I write this as a rails validation?

I just updated to rails 4.0.2 and I'm getting this warning: [deprecated] I18n.enforce_available_locales will default to true in the future. If you really want to skip validation of your locale you ...