There are many different methods that allow mapping an Array to a Hash in Ruby.

Array#to_h with a block (Ruby 2.6+)

You can call an array with a block that is called with each element. The block must return a [key, value] tuple.

This is useful if both the hash key and value can be derived from each array element:

users = User.all
user_names_by_id = users.to_h { |user| [user.id, user.name] }

{
  1 => "Alice",
  2 => "Bob"
}

Array#to_h on an array of key/value tuples (Ruby 2.1+)

Converts an Array ...

If you need to find all files inside a directory that were modified in the last 24 hours you can do this:

find . -mtime 1

You can also refer to another file's timestamp like this:

find . -cnewer other_file

This can be used to check against a specific timestamp, too. This is how you check for all files modified today (since 00:00):

touch -t `date +%m%d0000` /tmp/$$
find . -cnewer /tmp/$$

Note that $$ returns the current bash's PID so you will get some file like /tmp/12345 that stays the same for the current shell. This...

Do that for noble reasons only.

This will show you how to create a RSS feed that the Feed Validator considers valid.

Note that RSS is a poorly specified format. Consider using the Atom builder to make an Atom feed instead. Write a note here if you do.

1. Controller

Create a FeedsController to host the RSS feed. Such a controller is also useful to host other data feeds that tend to gather over the lifetime of an application, e.g. sitemap.xml.:

class...

Getting started with Ruby extensions in C.

The CSS Emoticons plugin is a simple jQuery plugin (and stylesheet) that allows you to turn any text emoticons on the page into cute little smiling faces with pure CSS3 styling (no images whatsoever).

If you want to rename a key of a Ruby hash, this could help you out.
Just put it into something like config/initializers/hash_move.rb.

In july Google announced a new version of their image serach tool Google Images. But you won't find it on the German google.de site. To reach the new - as I may say, very much better - tool from germany, you have to surf to images.google.com. Et voilà!

delocalize provides localized date/time and number parsing functionality for Rails.

First of all: You could just use RVM which would make the pain go away. If for some reason you can't, proceed.

Do not use rubygems from the apt repository.

1. Get the latest RubyGems TGZ
2. Change to the download directory and extract it:\
   tar xvfz rubygems-1.3.7.tgz
3. If you previously had RubyGems installed via apt: \
   sudo apt-get remove rubygems
4. Install RubyGems:\
   cd rubygems-1.3.7 && sudo ruby setup.rb
5. Link gem to gem1.8:\
   `sudo ...

Be careful!
The following solution will delete files on a volume. If you don't know exactly what you're doing, you can run into big trouble with your computer.

I play mp3 files on my car stereo that are stored on a SD-Card.
When I've copied those mp3 files to the FAT formatted SD-Card on my Mac, then I will see those nasty resource fork files (beginning with "._") for every file and folder on my car stereo. In most cases those resource fork files are important and invisible and don't bother you – on my car stereo ...

When you load a record with find options that have SQL fragments in :select or :joins, ActiveRecord will make that record read-only. This is a protective measure by Rails because such a record might have some additional attributes that don't correspond to actual table columns.

You can override that precaution by appending :readonly => false to affected find options or scope options.

Expiration of Rails sessions

By default Rails sessions expire when the user closes her browser window.

To change this edit your config/initializers/session_store.rb like this:

ActionController::Base.session = {
  :key          => '...',
  :secret       => '...'
  :expire_after => 10.years
}

In older Railses the initializer is not available. Set the option in the environment.rb instead:

config.action_controller.session = {
  :key          => '...',
  :secret       => '...'

...

Embedded Flash movies do not always obey element order and z-index.

To fix this, set the wmode attribute to transparent in both <object> and <embed> tags:

<object ... >
  <param name="wmode" value="transparent" />
  <embed ... wmode="transparent" />
</object>

When submitting textareas, browsers sometimes include carriage returns (\r) instead of just line feeds (\n) at the end of each line. I don't know when this happens, and most of the time it doesn't matter.

In cases where it does matter, use the attached trait to remove carriage returns from one or more attributes like this:

class Note
  does 'strip_carriage_returns', :prose, :code
end

Here is the test that goes with it:

describe Note do

  describe 'before_validation' do...

If you iterate over a collection of arrays, you can destructure the arrays within the block parameters:

movies_and_directors = [
  ['The Big Lebowski', 'Coen Brothers'],
  ['Fight Club', 'David Fincher']
]
movies_and_directors.each do |movie, director|
  # do something
end

For nested array (e.g. when you use each_with_index), you can use parentheses for destructuring:

movies_and_directors.each_with_index do |(movie, director), index|
  # do something
end

When a spec only runs when it is called directly, but not as part of the whole test suite, make sure the filename is foo_spec.rb instead of just foo.rb.

By default, Cucumber uses mocha. This note shows to use RSpec stubs and mocks instead.

Rspec 1 / Rails 2

Put the following into your env.rb:

require 'spec/stubs/cucumber'

Rspec 2 / Rails 3

Put the following into your env.rb:

require 'cucumber/rspec/doubles'

Note: Since Cucumber 4 it is important to require these lines in the env.rb and not any other file in support/* to register the hooks after any other After hook in support/*. Otherwise your doubles are removed, while other After steps requi...

Since RubyMine 3.1 you can drag tabs across panes/windows and out of the main window to create new windows.

For any version below 3.1 do it like this (will only allow dragging tabs inside their pane, not across panes):

1. File → Settings
2. Editor → Editor Tabs
3. Check "Show tabs in single row"

Seriously.

1. sudo apt-get install i8kutils
2. Reboot
3. You can now run the i8k tools such as i8kmon

Setting the fan speed to high (2) will only work shortly as the fan is somehow controlled automatically.\
This helps you out in bash:
while true; do i8kfan - 2; sleep 0.2; done

There should be a better solution and it will be posted as soon as it's found.

Call with the server's hostname (and user if you have no SSH agent), e.g.

install-gems-remotely my.server.com
# or without agent:
install-gems-remotely me@my.server.com

When you call it from a rails directory, it uploads your Gemfile, Gemfile.lock as well as the gemspecs of all vendored gems in to a temporary folder on the server and does a bundle install there.

If you need to install gems from anothere Gemfile, just do it like this:
BUNDLE_GEMFILE=Gemfile.something; install-gems-remotely my.server.com

This scri...

WMD is a simple, lightweight HTML editor for blog comments, forum posts, and basic content management. You can add WMD to any textarea with one line of code. Add live preview with one line more. WMD works in nearly all modern browsers, and is now completely free to use.

The following Haml will do:

%head{ :profile => 'http://www.w3.org/2005/10/profile' }
  %link{ :href => image_path('favicon.ico'), :rel => 'icon', :type => 'image/vnd.microsoft.icon' }

Note that while you can link to icon formats other than .ico, Internet Explorer is too stupid for that.