Under certain (unknown) circumstances, Rails will give localized files an invalid content-type in the Response header. For me, after requesting corporate_information and rendering corporate_information.de.html.haml, Rails sent a content-type of de.html instead of the expected text/html.

There are some discussions on this topic that offer workarounds, but no...

Shows how to implement an animated progress bar in pure CSS, without animated GIFs, Javascript or Flash.

Huge set of 315 free vector icons. You can choose which one you'd like, add your own SVGs, then download everything as an icon font or series of PNGs.

You can get up to 925 icons once you pay $59.

url = 'http://www.foocorp.com/foo/bar'
URI.parse(url).host
# => www.foocorp.com

Note that this will raise an error if the given argument is not a URL.

If you need the host's full URL without path, query, fragment etc., use URI.join with a clever twist:

url = 'http://www.foocorp.com:33546/foo/bar?query=foobar#hash'
URI.join url, '/'
# => http://www.foocorp.com:33546/

While git branch will show you all branches and highlight the current one with an asterisk, it can be too cumbersome when working with lots of branches.

To show only the branch you are currently on, use:

git rev-parse --abbrev-ref HEAD

Haml 3.1.2 displays single quotes in FormBuilder#text_ field html escaped. You may see something like that:

David's Chapter

Looking at the page's HTML, your field's values will be doubly escaped:

<input ... value="David&amp;#x27;s Chapter" />

Updating Haml to 3.1.5 or newer will fix it.

In theory you can take any scope and extend it with additional joins or conditions. We call this chaining scopes.

In practice chaining becomes problematic when scope chains grow more complex. In particular having JOINs in your scope will reduce the scope's ability to be chained with additional JOINs without crashes or side effects. This is because ActiveRecord doesn't really "understand" your scope chain, it only mashes together strings that mostly happen to look like a MySQL query in the end.

**I don't generally advice against u...

ActiveModel::Errors is used to handle validation errors on Rails objects. If you inspect an instance, it feels like a hash (to be more precise, it inherits from Hash):

errors = ActiveModel::Errors.new(Object.new)
=> {}
>> 
?> errors.add(:base, "foo")
=> ["foo"]
>> errors.add(:base, "bar")
=> ["foo", "bar"]
>> 
?> errors
=> {:base=>["foo", "bar"]}

If you need to hack anything with these errors, beware that it behaves in a special way. If you iterate over the errors it will decompose arrays.
For ...

Hashrocket Lunch n' Learn #1 with Avdi Grimm: Making Little Classes out of Big Ones

A look at the pros and cons of four different techniques for breaking a too-big class into smaller pieces.

In a nutshell:

If you require your Rails models manually, pay attention to the path you use. Unless you have to, don't do it at all.

Background

Consider these classes:

# app/models/user.rb

class User < ActiveRecord::Base
  validate :magic

  def magic
    errors.add_to_base('failed') if bad_things?
  end
end

^
# app/models/foo.rb

require 'user'

class Foo
  # something happens here
end

Now, when your environment is booted, Rails will automatically load your models, like User...

Show failing specs instantly. Show passing spec as green dots as usual.

Configuration:

# spec/spec.opts (.rspec for rspec 2)
--require rspec/instafail
--format RSpec::Instafail

Why is this useful?

• You can have a background image on the same element, overlaying it with a transparent gradient.
• Since you are probably using gradients to give an element a glossy or three-dimensional feel, box shadows work much better for this. This is because linear gradients always stretch to the full size of the element (which can grow with user input), while a natural shine or shadow only highlights a fixed size on the top or bottom.
• Browser support for linear gradients is a mess. I avoid using them. In part...

When is this useful?

• When both parent and child elements have borders, with this technique you don't get two borders (which looks ugly). This is because child elements are rendered over inset box shadows, not inside inset box shadows.
• You want more than one border on the same element. You can have as many inset box shadows on the same element as you like, e.g. allowing you to make a picture-frame-like border.

Examples

Remember the attribute list of box-shadow is x-offset, y-offset, blur radius, shadow r...

The (admittedly crazy) goal of this Gem is to be able to format/split all phone numbers in the world.

“Fat models” cause maintenance issues in large apps. Only incrementally better than cluttering controllers with domain logic, they usually represent a failure to apply the Single Responsibility Principle (SRP). “Anything related to what a user does” is not a single responsibility.

Early on, SRP is easier to apply. ActiveRecord classes handle persistence, associations and not much else. But bit-by-bit, they grow. Objects that are inherently responsible for persistence become the de facto owner of all business logic as well. And a year or tw...

In a Rails application, *_spec.rb files get special treatment depending on the file's directory. E.g. when you put a spec in spec/controllers your examples will have some magic context like controller, post or get that appears out of nowhere.

If you want that magic context for a spec in another folder, use the :type option:

describe CakesController, :type => :controller do
  ...
end

Makes a robust determination of a user's timezone through Javascript.

Takes a screenshot when you call it, or when a test fails.

This is for you if you get the following strange error from the state_machine gem:

undefined method `-' for #<StateMachine::BlacklistMatcher:0x124769b0>

You probably did something like this in your state_machine ... do block:

def self.final_states
  [ :foo, :bar ]
end

transition (all - machine.final_states - [:baz]) => :target_state

Instead, define the source states like this:

def self.final_states
  [ :foo, :bar ]
end

transition (all - (mach...

Turbolinks makes following links in your web application faster. Instead of letting the browser recompile the JavaScript and CSS between each page change, it keeps the current page instance alive and replaces only the body and the title in the head.

This is similar to pjax, but instead of worrying about what element on the page to replace, and tailoring the server-side response to fit, we replace the entire body. This means that you get the bulk of the speed benefits from pjax (no recompiling of the JavaScript or CSS) without having to tail...

The linked slidedeck holds many tips, of which I list the most interesting to me below

DATA and END

The __END__ keyword tells Ruby where a file ends – but you don't have to stop there. Any text you add after it is accessible via the DATA object.

Running the attached example file data.rb prints:

DATA is a File object to everything in the current file after "__END__"

No braces needed for 'special variables'

@instance, @@class, $global = [ 'instance', 'class', 'global' ]
puts "#@instance, #@@class, #$global"

...