Icon fonts like Font Awesome are infinitely scalable, look great on high-DPI displays and will give your app a modern look.

However, icon fonts can be very awkward to use compared to raster icons. Elements are given icons by giving them a special class like icon-plus or icon-home:

<span class="icon-plus">Create</span>

The icon font's stylesheet will then recognize this class and insert the icon as the element's :before style.

In practic...

You can use scheme-less URLs (or protocol-relative URLs) to have browsers use the current protocol (HTTP or HTTPS) when loading content referenced with such an URL.

A protocol relative URL doesn’t contain a protocol. For example, http://stevesouders.com/images/book-84x110.jpg becomes //stevesouders.com/images/book-84x110.jpg

Browsers substitute the protocol of the page itself for the resource’s missing protocol. Problem solved!

But:

Internet Explorer 7 & 8 will download st...

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...

Around will not happen until after a feature's Background has been processed. Use Before and After to avoid that.

Details

Consider this Cucumber feature file:

Feature: Something that needs to be tested

  Background:
    Given a user
      And I sign in        
    
  Scenario: Sign out
    When I sign out
    Then I should see "Signed out"
  
  Scenario: Something else
    # ...

Now, assume you have these step definitions:

Around do
  puts "** Around: before yield"

...

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...

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

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

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"

...

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.

The attached example file data.rb looks like this:

puts DATA.read

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

Running it with ruby data.rb prints:

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

Example task: Multiply the table holidays between several stages.

1. Open two terminals:

   shell-for stage_1
   shell-for stage_2
   

2. Get the stage1 and stage2 MySQL credentials:

   cat /opt/www/the_stage.host.tld/current/config/database.yml
   cat config/database.yml # should do it
   

3. Dump the table to a path reachable by the stage2 user (e.g. home):

   mysqldump -h mysql1 -u stage_1_user -p stage_1_database table_name > ~/table_name_dump.mysql # Select certain records using --where "some_id > 666"
   

   (-...

If some of your JavaScripts fail on Internet Explorer, but only in staging or production environments, chances are that JavaScript compression is the culprit.

By default, Rails 3.2 compresses JavaScript with UglifyJS. I have seen a few cases where this actually breaks functioning JavaScript on IE (one example is the CKEditor).

I fixed this by switching to Yahoo's YUI Compressor.

To do this, do the following:

• replace the uglifier gem with the yui-compressor gem...

This didn't work for me. Seems display is already taken in Machinist.

# in spec/support/blueprints.rb
Partner.blueprint do
   company_name
   display { true }
end

You're using exception_notification and want to send exception mails within a model. Here's how.

The ExceptionNotifier class has a method notify_exception for that. Simply pass an exception:

ExceptionNotifier.notify_exception Exception.new("testfoo")

=> #<Mail::Message:77493640, Multipart: false, Headers: <Date: Mon, 24 Sep 2012 13:37:00 +0200>,
<From: foo@example.com>,
<To: ["fail@failtrain.com", "fail@failbus.org"]>,
<Message-ID: <5060543b3759_212311986a0305e...

This describes how to migrate an existing cucumber test suite to Spreewald.

0. Add the gem

1. Include spreewald into your cucumber environment by putting
   require 'spreewald/web_steps'
   require 'spreewald/email_steps'
   # ...
   or just
   require 'spreewald/all_steps'
   into your support/env.rb.

2. Look through your step definitions for everything that might be included in Spreewald. Candidates are web_steps, shared_steps, table_steps, `em...

TL;DR Avoid before(:context) (formerly before(:all)), use before(:example) (formerly before(:each)) instead.

If you do use before(:context), you need to know what you are doing and take care of any cleanup yourself.

Why?

Understand this:

• before(:context) is run when the context/describe block begins,
• before(:context) is run outside of transactions, so data created here will bleed into other specs
• before(:example) is run before each spec inside it,

Generally, you'll want a clean setup for each s...

Today I got a better understanding of how git works, in particular what git checkout and git reset do.

Git basics

• A commit holds a certain state of a directory and a pointer to its antecedent commit.
• A commit is identified by a so-called ref looking something like 7153617ff70e716e229a823cdd205ebb13fa314d.
• HEAD is a pointer that is always pointing at the commit you are currently working on. Usually, it is pointing to a branch which is pointing to that commit.
• Branches are nothing but pointers to commits. Y...

Ever wanted autocompletion for paths from paths.rb in Cucumber? This card lets you write your steps like this:

When I go to path *press tab now* # path is replaced with a list of all known Cucumber paths

This is how you do it

(key shortcuts apply for TextMate2)

1. Open the bundle editor (ctrl + alt +  + B)

2. Create a new Item ( + N), select "Command"

3. Paste this:
   ^
   #!/usr/bin/env ruby -wKU
   require File.join(ENV['TM_SUPPORT_PATH'], 'lib', 'ui.rb')

   cucumber_paths = File.join ENV['TM_PROJECT_DIRECTORY'], 'features'...