I use this to simulate the (non-existing) :last-letter CSS pseudoclass, e. g. to insert a tombstone at the end of an article:

findLastLeaf = ($container) ->
  $children = $container.children()
  if $children.length == 0
    $container
  else
    $lastChild = $children.last()
    $lastContent = $container.contents().filter(->
      # Only return nodes that are either elements or non-empty text nodes
      @nodeType == 1 || (@nodeType == 3 && _.strip(@nodeValue) != '')
    ).last()
...

Since version 34, Chromium/Chrome ignores the autocomplete="off" attribute on forms or input fields. Recent versions of other browser do the same, although implementation details vary.

This is especially problematic for admin areas because Chrome might automatically fill in a password on a "add new user" forms.

Chrome developers say this is by design as they believe it encourages users to store more complex passwords.

Recommended fix for Chrome and F...

The error unexpected 'x' after 'DESCENDANT_SELECTOR' (Nokogiri::CSS::SyntaxError) (where x may be basically any character) occurs when the Nokogiri parser receives an invalid selector like .field_with_errors # or td <strong>.

In Cucumber, the culprit will be an invalid step definition that builds an invalid selector:

# inside some step definition:
field = find_field(label)
page.send(expectation, have_css(".field_with_errors ##{field[:id]}"))

The above raises the mentioned error if field[:id] is nil, i.e. the foun...

If you parse this Yaml ...

yes: 'Totally'
no: 'Nope'

... you get this Ruby hash:

{ true: 'Totally',
  false: 'Nope' }

In order to use the strings 'yes' and 'no' as keys, you need to wrap them with quotes:

'yes': 'Totally'
'no': 'Nope'

There's actually a long list of reserved words with this behavior:

y|Y|yes|Yes|YES|n|N|no|No|NO
|true|True|TRUE|false|False|FALSE
|on|On|ON|off|Off|OFF

I'm sorry.

You are probably using Ruby 1.8.7 with a too recent versions of Rubygems.

Downgrade your Rubygems to the latest version that works with 1.8.7.

See also

• Fix Rubygems warning: Gem.source_index is deprecated, use Specification
• Fix Rubygems binary error: undefined method `activate_bin_path' for Gem:Module (NoMethodError)
• [Bundler: Gemfile.lock is corrupt & gems are missing from the DEP...

If you get this error when you try to resize an OpenStack instance:

# nova resize example 23 --poll
ERROR: Resize requires a change in size. (HTTP 400)

You need to change your flavor to have a different memory size. It's a bug in an older OpenStack version:

        # /nova/compute/api.py
        if (current_memory_mb == new_memory_mb) and flavor_id:		
            raise exception.CannotResizeToSameSize()

which got fixed 2012-09-12 ([https://git.openstack.org/cgit/openstack/nova/commit/nova/compute/api.p...

There are 3 built-in file descriptors: stdin, stdout and stderr (std=standard). (You can define your own, see the linked article.)

Basic

• 0/1/2 references stdin/stdout/stderr
• >/2> redirects stdout/stderr, where > is taken as 1>
• &1/&2 references stdout/stderr
• &> redirects stdout and stderr = everything (caution: see below)

Caution: &> is functional as of Bash 4. This seems to result in a slightly differing behaviour when redirecting output in Ru...

quiet_assets helps with disabling asset pipeline log messages in the development log. When the gem is added, asset pipeline logs are suppressed by default.

If you want to disable muting temporarily, add config.quiet_assets = false to your config/application.rb.

Cucumber_rails' old-school web-steps have been deprecated for a while, urging developers to write high-level step definitions that directly use Capybara or Webrat.

We think that's a bit drastic. More high-level steps are good, but ticking the odd check box with a general step is not always bad.

So we took the old web steps, improved them a bit, added some other favorites of ours (steps for emails, tables, [time travelling](/ma...

If you once had HTTP Strict Transport Security enabled for a domain, and you want to disable it again, you need to send this header over a secure connection:

Strict-Transport-Security: max-age=0;

The next time a browser visits your site, it will forget that it was once flagged as HTTPS-only.

Should you need to remove the HSTS flag from your local browser (e.g. for debugging), you can do so in Chrome by accessing [chrome://net-internals/#hsts](chrome://net-internals/#hs...

Edge Rider gives your relations a method #origin_class that returns the class the relation is based on.
This is useful e.g. to perform unscoped record look-up.

Post.recent.origin_class
# => Post

Note that #origin_class it roughly equivalent to the blockless form of #unscoped from Rails 3.2+, but it works consistently across all Rails versions. #unscoped does not exist for Rails 2 and is broken in Rails 3.0.

React.js is a relatively new Javascript templating engine that has two-way-bindings like AngularJS or Batman. The interesting idea here is that React keeps a virtual copy of the DOM tree in memory, and when you re-render, it only changes the DOM as little as required. That means if you re-render a list with 1000 items, and only one item has changed, the browser-DOM will only remove and add a single element instead of 1000 elements. This makes React.js views insanely fast.

The attached article proposes that React.js is so fast that you don...

Spring is a Rails application preloader. When debugging e.g. the rails gem, you'll be wondering why your raise, puts or debugger debugging statements have no effect. That's because Spring preloads and caches your application once and all consecutive calls to it will not see any changes in your debugged gem.

Howto

Disable spring with export DISABLE_SPRING=1 in your terminal. That will keep Spring at bay in that terminal session.

In Ruby, [you can only write environment variables that subproc...

MenuetOS is an Operating System in development for the PC written entirely in 32/64 bit assembly language. Menuet64 is released under License and Menuet32 under GPL. Menuet supports 32/64 bit x86 assembly programming for smaller, faster and less resource hungry applications.

• Fits on a single floppy, boots also from CD and USB drives
• Responsive GUI with resolutions up to 1920x1080, 16 million colours
• Free-form, transparent and skinnable application windows, drag'n drop
• SMP multiprocessor support with currently up to 8 cpus
• IDE: E...

General

Programatically invoke Rails generators

Require the generator, instantiate it and invoke it (because generators are Thor::Groups, you need to invoke them with invoke_all). Example:

  require 'generators/wheelie/haml/haml_generator'
  Generators::HamlGenerator.new('argument').invoke_all

Other ways: Rails invokes its generators with Rails::Generators.invoke ARGV.shift, ARGV. From inside a Rails generator, you may call the [inherited Thor method invoke(args=[], options={}, config={})](https://github...

docopt helps you define interface for your command-line app, and automatically generate parser for it.

docopt is based on conventions that are used for decades in help messages and man pages for program interface description. Interface description in docopt is such a help message, but formalized. Here is an example:

Naval Fate.

Usage:
  naval_fate ship new <name>...
  naval_fate ship <name> move <x> <y> [--speed=<kn>]
  naval_fate ship shoot <x> <y>
  naval_fate mine (set|remove) <x> <y> [--moored|--drifting]
  naval_fate -h |...

This note summarizes the ruby exception hierarchy.

Exception
  NoMemoryError
  ScriptError
    LoadError
    NotImplementedError
    SyntaxError
  SignalException
    Interrupt
      Timeout::Error    # < ruby 1.9.2
  StandardError         # caught by rescue (default if no type was specified)
    ArgumentError
    IOError
      EOFError
    IndexError
    LocalJumpError
    NameError
      NoMethodError
    Ran...

When you want the table headers to always stay around (e.g. because that table is huuuge), use the code below.

Style

table.fixed_table_header{
  position: fixed;
  top: 0;
  width: auto;
  display: none;
  border: none;
  margin: 0;
}

Javascript

;(function($) {
   $.fn.fixHeader = function() {
      return this.each(function() {
         var $table = $(this),
            $t_fixed;

         function init() {
            $t_fixed = $table.clone();
            $t_fixed.find('tbody').remove().end().addClass('fi...

If you want to label things with a color but don't actually care which cholor, you can use the attached Colorizer class.

To get a completely random color (some of which will clash with your design):

Colorizer.colorize(some_object) # => "#bb4faa"

To get similiar colors (e. g. bright, pale colors of different hues):

 # random hue, saturation of 0.5, lightness of 0.6
Colorizer.colorize_similarly(some_object, 0.5, 0.6) # => "#bbaaaa"

Also see the color gem.

So you have a restangular collection and you want to remove an element from it, after you've successfully deleted it from the server.

The README suggests to say something like $scope.users = _.without($scope.users, user). While that works at first glance (the element is no longer in your collection), it will break horribly when you want to use restangular's attributes on that collection.

This...

If you regularly get ActionView::MissingTemplate exceptions, maybe some bot visits your site requesting silly formats like:

http://www.rails-app.com/makandra.html-username-2000 # => Rails tries to retrieve 'makandra' with format 'html-username-2000'

Just restrict accepted format parameters for the whole application like this:

class ApplicationController < ActionController::Base

  before_filter :refuse_silly_formats

  private

  def refuse_silly_formats
    acceptable_formats = %w[html xml pdf]

    if par...