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This is a collection of articles I wrote over the last couple of years. These days, I usually write about building and launching software products.

Typing SSH passwords again and again can be a real pain. For example: Lately I started to use Capistrano to deploy my rails applications. If I want to set up the maintenance-page on the server I’ll type cap deploy:web:disable which of course prompts me for the SSH password. Then I want to deploy my application with cap deploy and again will be prompted for the password. Finally I have to cap deploy:web:enable to remove the maintenance page which as mindful readers might have guessed already prompts for the password. This was just one reason for me to set up SSH authentication keys. At first I was a little worried that setting it up might be a bit complicated. Luckily I was disabused. If you want to switch to key based authentication too follow these simple steps.

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By default it’s not possible to use a database-column called type for anything else than single table inheritance. To change this, simply use set_inheritance_column() and read_attribute():

class TypeTest < ActiveRecord::Base
  set_inheritance_column(:something_else)

  def type
    read_attribute(:type)
  end

  def type=(value)
    write_attribute(:type, value)
  end
end

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I needed a way to get a list of the subclasses that inherit a specific. Unfortunately there is no method like Class.subclasses (there is Class.superclass, though) so I had to look for another way to achieve this. Let’s say, we want to have an array containing all subclasses as a class variable of our superclass Strategy. In order to fill the array we’ll overwrite the inherited class method of Class.

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