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Bundler 1.1 has been released, is very fast

Bundler 1.1 has been released. With this version you no longer need to wait for this:

Fetching source index…

The new Bundler is smarter and can fetch required metadata in a few seconds.

You can install the new version by saying:

sudo gem install bundler
External content

Sass: Use black or white foreground color depending on the lightness of the background

This article shows how to create a Sass mixin for a colored button. The button's foreground color is dynamically chosen between either black or white, depending on the given background color.

It's a nice intro into @if and @else conditionals in Sass.

Spec "content_for" calls in helpers

This only applies to RSpec below version 1.3.2. The issue has been fixed in RSpec 1.3.2, and most likely RSpec 2 and later versions.

When you have a helper that calls content_for and want to check its behavior you should probably write a feature instead. If you still want to do it, mind the following.

Consider this helper:

module LayoutHelper
  def title(string)
    content_for :title, string

Somewhere in the layout we'd then say something like this: `<%= yield :title %...

Debugging Google Analytics

If you need to debug Analytics tracking, consider using this chrome extension. It will replace the tracking code with a debug version that prints debugging info to the JavaScript console.

Markdown/Kramdown examples

This card shows you how to format a card's content using Markdown. We use the Kramdown interpreter, so here are examples for its dialect.








> Quoted text

Quoted text

Here is [a link](

Here is a link.

![An image; this is the alt text](…

Creating the inverse of a Rails migration

Let's say you need to revert a migration that happened a while back. You'd create a new migration that removes what was added back then in the up path, while its down path restores the old functionality.

While you could just copy&paste the down and up parts of it to the inverse part of the new migration, you may not want to do that. Especially when the up/down paths already contained some logic (that executed update statements on the created column, for example), copying does not feel right.

Someone already added the logic how to…

Install the typhoeus gem with native extensions

If you get this:

Installing typhoeus (0.3.3) with native extensions
/usr/local/lib/site_ruby/1.8/rubygems/installer.rb:483:in `build_extensions': ERROR: Failed to build gem native extension. (Gem::Installer::ExtensionBuildError)

/usr/bin/ruby1.8 extconf.rb 
checking for curl/curl.h in /opt/local/include,/opt/local/include/curl,/usr/include/curl,/usr/include,/usr/include/curl,/usr/local/include/curl... no
need libcurl

You can fix it by installing the libcurl3-dev package:

sudo apt-get install libcurl3-dev

Now you should…

Find out your SSH key's fingerprint (e.g. to authenticate on GitHub)

If you want to know your public key's fingerprint, do this:

ssh-keygen -lf ~/.ssh/

This may be necessary to authenticate your key on GitHub because of recent events – you need to do that if you get an error like this when talking to them (to pull etc):

ERROR: Hi foobear, it's GitHub. We're doing an SSH key audit.
Please visit…
to approve this key so we know it's safe.
Fingerprint: ab:cd:ef:…

RubyMine: Disable window animations

Under Settings / Appearance you can uncheck a box Animate windows. This will change your life.

Compare two XML strings as hashes

Let's say you have two XML strings that are ordered differently but you don't care about the order of attributes inside containers:

a = '<?xml version="1.0" encoding="UTF-8"?><Authenticate><User>batman</User><Password>secret</Password></Authenticate>'
b = '<?xml version="1.0" encoding="UTF-8"?><Authenticate><Password>secret</Password><User>batman</User></Authenticate>'

Working with plain string comparison is not helpful, of course:

a == b
=> false

Instead, you can use the Nori gem …

ActiveRecord: Overwriting a setter causes trouble with attributes depending on each other

Undeterministically I got a nil error on saving the object caused by the random order of hash elements of the params hash.

class Feedback
  belongs_to :user

  def role=(value)
    @role = value = find_email_by_name(

This piece of code works well until the object params hash contains a second element when it is updated like this:


Now it is no longer ensured that user was set before name was set. If the name…

RubyMine: Find and execute a menu action by its name

You are looking for a functionality in RubyMine but don't know or remember its keyboard shortcut or which menu it is located in?\
Hit Ctrl+Shift+A.

This will bring up the "Find Action" box where you can enter an action's name or category. Pick the result from the list to run it.

The list of results will also show you any assigned keyboard shortcuts.


External content

Online tool to test how a site behaves in popular desktop, tablet and phone resolutions.

Setup or update Passenger to use Ruby Enterprise

  1. Your current ruby must be Ruby Enterprise.
  2. gem install passenger
  3. passenger-install-apache2-module
  4. Edit your httpd.conf according to the instructions provided at the end of the setup script.
  5. Restart Apache: sudo service apache2 restart

This also works when you previously ran your Passenger using MRI. Just run the setup as described.

Install the gherkin gem with native extensions

When trying to install the gherkin gem, you might well encounter an error saying:

cc1: warnings being treated as errors

If upgrading is not an option (corresponding issue on github), you can install it properly by changing the compiler flags as follows:

gem install gherkin -v '2.2.9' -- --with-cflags=-w

If you cannot install the specific version you intent to, try uninstalling the gem first.

To install the gem with bundler you can to do this:

bundle config build.gherkin...

Git: Remove information on branches that were deleted on origin

When branches get deleted on origin, your local repository won't take notice of that.

You'll still have your locally cached versions of those branches (which is actually good) but git branch -a will still list them as remote branches.

You can clean up that information locally like this:

git remote prune origin

Your local copies of deleted branches are not removed by this.

The same effect is achieved by using (kudos to Julien):

git fetch --prune

You could also set that as a default.

External content

TodoMVC - A common learning application for popular JavaScript MV* frameworks

Developers these days are spoiled with choice when it comes to selecting an MV* framework for structuring and organizing JavaScript web apps. Backbone, Spine, Ember (SproutCore 2.0), JavaScriptMVC… the list of new and stable solutions goes on and on, but just how do you decide on which to use in a sea of so many options?

To help solve this problem, we created TodoMVC - a project which offers the same Todo application implemented using MV* concepts in most of the popular JavaScript MV* frameworks of today.

Solutions look and feel the same…

RubyMine: Exclude data and log directories from a project

RubyMine offers you to exclude directories from search, meaning faster search results and less "noise" in the list of result.

Right-click a folder in your project tree and click "Mark Directory As" → "Excluded".

Do it for your your log, data, and other directories that you don't need to access during development and whose search results are irrelevant.
They won't be deleted but simply ignored when searching across a project's files.

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