Changing an association and its foreign key on the same ActiveRecord object can lose the later assignment; the association value wins on save.

Quoted Sass mixin arguments can produce invalid CSS for multi-part values like box-shadow. unquote removes the quotes so generated properties stay valid.

Range#include? becomes slow for non-numeric ranges in Ruby 1.9, while Range#cover? is unavailable in 1.8.7. A compatibility method keeps one check working across both versions.

RubyGems 1.6 can break Capistrano by activating incompatible net-ssh versions; isolating Capistrano in a dedicated Bundler Gemfile restores deployment commands.

Pivotal Tracker supports keyboard shortcuts for quick navigation, search, help, story creation, and toggling backlog, charts, current, done, history, icebox, my work, and labels.

RubyGems 1.6.0 can break Rails 2.x with ActiveSupport::Dependencies::Mutex NameError during startup; loading thread before boot.rb prevents the failure.

Wallaby converts artwork and animation from Adobe Flash Professional FLA files into HTML for wider reach on devices without Flash runtime support.

Distinguish between a simple attribute and an associated object in Person; reflect_on_association lets code branch when a getter refers to a relation.

If you want to get a deep understanding of how closures, blocks, procs & lambdas in Ruby work, check out the code at the attached link.

Here the summary:

^
---------------------------- Section 6: Summary ----------------------------

 So, what's the final verdict on those 7 closure-like entities?          

                                                     "return" returns from closure
                                    True closure?    or declaring context...?         Arity check?
                         ...

MIN() and MAX() aggregate across rows, not within one row; LEAST() and GREATEST() return the smaller or larger value for the current row.

Currently, only up to 500 rows of Analytics table data can be exported at a time into CSV format. If you need to export larger data sets, like exporting all keywords that sent traffic to your site, you can export multiple times as long as each batch contains at maximum 500 rows.

If you have thousands of rows that require multiple exports, you can use the convenient workaround below to export all your rows in one go.

Dual-monitor setups with NVIDIA on Linux can crash X when DDC/CI is enabled on Dell displays; disabling DDC/CI avoids the failure.

Rails form fields can clash when the same form is rendered multiple times; a prefix keeps field IDs unique without changing submitted names.

Flash movies can exchange data with JavaScript in the same page, with ExternalInterface as the preferred bridge and fscommand or SetVariable() as legacy options.

Typing en-dashes, em-dashes, and other symbols is awkward without a compose key. A configured compose key enables cross-application input of special characters on Linux.

A while ago we were working on an application that had an entire version specially created for mobiles, such as the iPhone. This specific application was entirely tested with Capybara, Steak and Selenium Webdriver. Although the test suite wasn’t the fastest one in the world, the web application was very well tested, and to guarantee that we would also be testing the mobile version, we would have to simulate an iPhone user agent accessing the application.

But wait, you might be thinking that we are not able to change browser headers while ...

Paperclip supports ImageMagick resize flags for scaling, cropping, and fitting images to specific dimensions without distorting them.

Quoted text in Cucumber steps can break matching because escaped quotation marks are not handled reliably. Regex steps, capture groups, or Spreewald multiline strings avoid the issue.

Windows lacks a direct sudo equivalent; elevation usually relies on running a shell as Administrator, runas, or third-party tools with limitations.

Open a terminal window faster by assigning a custom keyboard shortcut to Ubuntu’s terminal launcher; avoiding clashes with existing app shortcuts prevents conflicts.

32-bit Ruby Time values stop at 2038-01-19 03:14:07 UTC; later timestamps raise ArgumentError. DateTime can store later dates but differs from Time and is slower.

Relocating MySQL storage can free space or move databases to another disk, but configuration and AppArmor access must match the new path.

What are Google’s plans for turning WebM into a genuinely open standard, one that is based on consensus like the rest of W3C’s HTML5 effort? Would Google fully support such an effort? Even the WebM project’s domain is controlled by Google. Google chose to release WebM under the Creative Commons license which would theoretically allow a standards body to use the specification as a basis for a truly open standard. Would Google agree to adopt the specification and changes that would emerge from an open process in a timely and robust manner? Wha...