Passenger ignores RailsEnv directive for Rails 3 applications

Passenger gives you the possibility to define in which environment your app should be started.
This has to be added to the VirtualHost configuration for Apache for Rails 2 applications:

RailsEnv development

When running Rails 3, you need

...

After switching to Rails 3 you may get a LoadError with the following message when trying to use your application via passenger:
no such file to load -- dispatcher

Your Passenger version is most likely out of date.

Update the gem, then ins...

Find conditions for scopes can be given either as an array (:conditions => ['state = ?', 'draft']) or a hash (:conditions => { 'state' => 'draft' }). The later is nicer to read, but has horrible security implications in some versions of Ru...

Webpacker is Rails' way of integrating Webpack, and version 4 has been released just a few days ago, allowing us to use Webpack 4.

I successfully upgraded an existing real-world Webpack 3 application. Below are notes on everything that I encounte...

When writing a piece of reusable code, you sometimes need to have separate code for Rails 2 and Rails 3. You can distinguish between Rails versions like this:

if Rails.version < '3' # mind the quotes
  # Rails 2 code goes here
else

...

This card explains how to generate an entity relationship diagram for your Rails application.
We also show how to limit your ERD to a subset of models, e.g. models inside a namespace.

Generating a full ERD

Option A: RubyMine

1. Right-cli...

Leads to awesomeness and unicorns when used in production.

To obtain a list of Passenger processes with their application directories and memory usages, you can say

sudo passenger-memory-stats

This will output a list like this:

----- Passenger processes -----
PID    VMSize    Private  Name

...

Ever wondered how Rails talks to itself in a Cucumber feature? In Rails 3 you can do it like this:

def rack_env(path)
  { "rack.input" => {},
    "PATH_INFO"=>"#{path}",
    "REQUEST_METHOD"=>"GET" }
end

request = rack_en...