Ruby's regular expressions can be represented differently.
When serializing them, you probably want to use inspect instead of to_s.

For the examples below, consider the following Regexp object.

regexp = /^f(o+)!/mi

to_s

Using to_s will use a format that is correct but often hard to read.

>> regexp.to_s
=> "(?mi-x:^f(o+)!)"

inspect

As the Ruby docs say:

...

If you get an error like this for a puppet mount:

$ > puppet agent --test 
Info: Retrieving pluginfacts
Info: Retrieving plugin
Info: Loading facts
Info: Caching catalog for example.makandra.de
Info: Applying configuration version '1483001792'
Info: Computing checksum on file /etc/fstab
Info: FileBucket got a duplicate file {md5}34b9adc036cf1dbd2392df84f921547d
Notice: /Stage[main]/Foobar/Swap_file::Files[default]/Mount[/var/swapfile]/ensure: defined 'ensure' as 'defined'
Error: /Stage[main]/Foobar/Swap_file::Files[default]/Mount[/var/s...

Have you tried the Search everywhere dialog? You can open it by pressing Shift twice.

Font Combiner offers a way to tweak and adjust any TTF or OTF font (license permitting), by bringing in font glyphs as vector shapes, providing a completely overhauled font generated to the user's specification with alternative metrics options, alternative hinting types, kerning and spacing options and the facility to make any average free font look great.

Examples are here

So you're getting an error like this:

undefined method `activate_bin_path' for Gem:Module (NoMethodError)

Here is what happened:

• You installed a recent version of Rubygems
• You installed some gems that install a binary (like bundle, rake or rails) with code that only works with modern Rubygems versions
• You downgraded Rubygems to an older versions, which doesn't change any binaries
• When calling binaries with the old Rubygems version, it cannot process the line Gem.activate_pin_path(...) that was written out by th...

TL;DR: Update the 'net-ssh' gem by adding to your Gemfile:

gem 'net-ssh', '=2.9.1'

Now run bundle update net-ssh. It has no dependencies so it shouldn't update other gems.

If you're using Ruby 1.8.7 and want to update net-ssh to a version > 2.9.1 you also need to add this to your gemfile:

gem 'backports', :require => false

... and in your deploy.rb add this:

require 'backports/1.9.2/array/select' 

Background

You propably have an older version of Capistrano and thereby an older version of `n...

Put the following into config.ru in your Rails root folder:

# Require your environment file to bootstrap Rails
require ::File.dirname(__FILE__) + '/config/environment'

# Dispatch the request
run ActionController::Dispatcher.new

Otherwise, your Rails 2.3 project will not be considered by Passenger 5+ and you will probably see 403 errors returned by nginx or Apache.

So you're getting this failure when running bundle install on an older project:

Your Gemfile.lock is corrupt. The following gems are missing from the DEPENDENCIES section: 'archive-tar-minitar' 'hoe' 'rcov'

This happens when you are using a new version of Bundler with a project that was bundled with a very old version of Bundler. For reasons unknown, the Bundler dependency API returns different dependencies for some gems (like ruby-debug or rainpress) than the dependencies found in the downloaded gemspecs. While old versi...

With ngAnimate, you can easily animate certain events (see directive support). We'll make use of ngClass animations to style an element on changed binding value.

Say we have a slider and a separate details container. Each time the slider changes, we want to "flash" the details container by hiding it and fading it back in.

HTML

Add a custom class to the element you want to animate, i.e. the details container:

<div class="details slide-index-{{ currentSlideIndex }}">
  {{ co...

• Plot graphs in Ruby
• WebGraphviz renders in your browser via JavaScript (to store the rendered graph, extract the SVG using your browser's DOM inspector)
• GraphViz with DOT: Online http://graphs.grevian.org/graph https://graphviz.christine.website/ or offline https://makandracards.com/makandra/1589-auto-generate-state_machine-graphs-as-png-images
• Balsamiq
• Draw.io
• [Excalidraw](https:...

Like you know from "How to tell ActiveRecord how to preload associations (either JOINs or separate queries)", you can tell ActiveRecord explicitly if it should use a LEFT OUTER JOIN or a separate query to preload associations.

Here is some special case, where a simple includes is not possible. For the diagram below we want to sort the rides by the translated name of the departure_place and the arrival_place:

![6020905239052288.png](https://makandracards.com/makandra/43252-howto-combine-custom-sql-with-preload/a...

The linked article states that CSS breakpoints should group "similar" screen sizes and thus be at:

• 600px "narrow"
• 900px "medium"
• 1200px "wide"
• (1800px) "huge"

By choosing these breakpoints, most device screens will be somewhere between two breakpoints, and not at the very edge of them.

The ranges could be called:

• narrow (< narrow)
• medium (narrow - medium)
• normal (medium - wide)
• wide (wide - huge)
• huge (> huge)

Easy mode

This method will remove automatically installed packages that no other packages depend on any more. This, of course, includes obsolete kernel versions, with the explicit exception of the currently running kernel, the kernel version that was installed on the system before that and, of course, the latest updated version of the kernel. However, it will also remove any and all other packages that have been marked as installed automatically but have no other packages depending on them. This could lead to unexpected removal of packag...

If you use awesome 3.5, and a gnome or mate panel, the panel will often receive focus when you switch desktops. As a workaround:

1. Add this rule to your rc.lua:

   { rule = { class = "Mate-panel" }, properties = { ontop = true, focusable = false } }
   

2. Replace /usr/share/awesome/lib/awful/autofocus.lua with the attached file

If your external displays not switching on or showing a weird behavior (for e.g. all displays getting the same configuration all the time) you can fix it by switching off all external displays and re-enabling only one in the first step. Afterwards you can apply your whole configuration via xrandr. This behavior could be a bug in the kernel and may be fixed in linux 4.8.

Example display configuration

Screen 0: minimum 8 x 8, current 5760 x 1200, maximum 32767 x 32767
eDP1 connected 1920x1080+0+0 (normal left inverted right x axis...

When giving a presentation with a projector it is sometimes better to use a dual screen layout instead of a cloned display. If you still want a preview of the projector screen on your primary screen, you can do this:

0. Install x11vnc and a vnc viewer (e.g. xtightvncviewer).

1. Connect the projector.

2. In your system display settings, move the projector to the left or your primary screen (not strictly necessary, but I had weird clipping issues otherwise).

3. Start a vnc server for your second display with

   x11vnc -clip xinera...
   

When running tests via parallel_tests, you may encounter an error:

cannot load such file -- parallel_tests/gherkin/runtime_logger
Error creating formatter: ParallelTests::Gherkin::RuntimeLogger (LoadError)

This will happen when you upgrade Bundler to version 1.13.x and appears to be "by design" since there is a Bundler config option to restore previous behavior.

You can fix it by setting that flag. You should commit the resulting config file into the repository!

bundle config --local disable_exec_load true

There is a Git...

When testing your command line application with Aruba, you might need to stub out other binaries you don't want to be invoked by your test.

Aruba Doubles is a library that was built for this purpose. It is not actively maintained, but works with the little fix below.

Installation

Install the gem as instructed by its README, then put this Before block somewhere into features/support:

Before do
  Arub...

A Rake task appears in rake -T if it has a description:

desc 'Compile assets'
task :compile do
  ...
end

To not list it, simply omit the description:

task :compile do
  ...
end

You can also hide a Rake task that has been defined by someone else (like a gem) by removing the description:

Rake::Task['compile'].clear_comments

Or you can whitelist which tasks should be listed:

visible_tasks = %w(compile build package)
Rake::Task.tasks.each do |task|
  visible_tasks.include?(task.name) or task.clear_comments
en...

When you're writing specs for ActiveRecord models that use memoization, a simple #reload will not do:

it 'updates on changes' do
  subject.seat_counts = [5]
  subject.seat_total.should == 5
  # seat_total is either memoized itself, or using some
  # private memoized method
  
  subject.seat_counts = [5, 1]
  subject.seat_total.reload.should == 6 # => Still 5
end

You might be tempted to manually unmemoize any memoized internal method to get #seat_total to update, but that has two disadvant...

Yesterday I stumbled across a talk in which the guy mentioned module sub-classing. I was curious what you can do with it and found his blog post with a cool example. It allows you to inject some state into the module you are including elsewhere. Check it out!

class AttributeAccessor < Module
  def initialize(name)
    @name = name
  end

  def included(model)
    super
    define_accessors
  end

  private

  def define_accessors
    ivar = "@#{@name}"
    define_writer(ivar)
    define_reader(ivar)
  end

  def define_writer(ivar)
    ...

A haml angular 1 template with

.thing(class="is-{{:: item.type }}")

will be compiled (by haml) to

<div class="is-{{:: item.type thing }}"></div>

which is not what you want! It will also crash in angular (unless thing is a valid variable in your angular directive) with Error: [$parse:syntax] Syntax Error: Token 'thing' is an unexpected token at column 11 of the expression [item.type thing]

Solution 1: Use ng-class instead of class

.thing(ng-class='"is-{{ item.type }}"')

**Solution 2: Don't let haml b...

In order to have monitoring for Sidekiq (like queue sizes, last run of Sidekiq) your application should have a monitoring route which returns a json looking like this:

{
  "sidekiq": {
    "totals": {
      "failed": 343938,
      "processed": 117649167
    },
    "recent_history": {
      "failed": {
        "2016-11-06": 1,
        "2016-11-07": 46,
        "2016-11-08": 0,
        "2016-11-09": 0,
        "2016-11-10": 0
      },
      "processed": {
        "2016-11-06": 230653,
        "2016-11-07": 230701,
        "2016-11-08"...

Angular comes with different types of services. Each one with its own use cases.

All of these services are singletons. You probably want to use Factory all the time.

Provider

• is the parent of all other services (except constant)
• can be configured using `app.config(function(Provider) { ...})
• a little complex

Factory

• simpler than Provider, but without configuration
• definition: `app.factory('name', someFunction)
• someFunction is called when the name service is instantiated and should return an object

Se...