Awesome hack by Tim VanFosson:

<img src="some.jpg" onerror="this.src='alternative.jpg'" />

Instead of this:

Image.order('images.created_at DESC')

You can write this:

Image.order(created_at: :desc)

Not only do you not have to write SQL, you also get qualified column names (created_at becomes images.created_at) for free.

Multiple order criteria

To add secondary order criteria, use a hash with multiple keys and :asc / :desc values:

Image.order(title: :asc, created_at: :desc)

It's generally not trivial to change a datetime's seconds, minutes, etc in SQL. Here is how it works when speaking PostgreSQL.

Consider you have a timestamp column whose seconds you want to zero:

SELECT born_at FROM users;
       born_at
---------------------
 2015-05-01 13:37:42

You can the TO_CHAR function to convert date or time values into a string, and do your changes there:

SELECT TO_CHAR(born_at, 'YYYY-MM-DD HH24:MI:00') FROM users;
       to_char
---------------------
 2015-05-01 13:37:00

...

Today I learned that Ruby on Rails has shipped with a built-in slug generator since Rails 2.2:

> "What Up Dog".parameterize
=> "what-up-dog" 

> "foo/bar".parameterize
=> "foo-bar" 

> "äöüß".parameterize
=> "aouss" 

Also see: Normalize characters in Ruby.

Clever hack using data-attributes to assign labels to cells.

It's still a massive duplication of code (labels), but better and more lightweight than most solutions I've seen for this surprisingly tricky problem.

File logger

If you need to log to a file you can use Ruby's Logger class:

require 'logger'

log = Logger.new('log/mylog.log')
log.info 'Some information'
log.debug 'Debugging hints'
log.error StandardError.new('Something went wrong')

Logger does a number of things well:

• Message type (info / debug / error) is logged
• Log entries are timestamped
• Writing log output is synchronized between threads
• Logged errors are printed with full backtraces

If you don't like the output format, you can define a custom formatter.

I ha...

Dusen (our search gem) is now capable of excluding words, phrases and qualified fields from search.
E.g. search for

• included -excluded
• "search this" -"not that"
• topic:"Yes" -topic:"No"

This will soon also work in makandra cards!

Reason

If you are using Coffeescript, it is likely to be the culprit. Since Coffeescript always returns the value of the last expression, it may return DOM nodes:

# coffeescript
scope.focus = ->
  element.focus()

# javascript
scope.focus = function() {
  return element.focus(); // wheee
}

If you e.g. use this function like this, the error will be raised:

<span ng-click="focus()">...</span>

Solution

By adding an explicit return value (e.g. return false), you can Coffees...

What if a complicated component comes along that is naturally modeled by multiple directives? This group of directives, as a whole, form a single self contained component. None of directives in the group can stand alone because they only make sense when used together; they collaborate; they are aware of each other and need to communicate with each other.

This post will discuss best practices for managing communication among collaborating directives and illustrate these practices with an example.

This is useful to kill processes like ruby my-script.rb:

pkill -f my-script.rb

With great power comes great responsibility.

Check your GPU state on chrome://gpu. If it reads "WebGL: Hardware accelerated" in the first list, you're set. Else:

1. Make sure chrome://flags/#disable-webgl is disabled (there should be a link "Enable")
2. If that does not help, try to additionally enable chrome://flags/#ignore-gpu-blacklist.

TL;DR You shouldn't call $scope.$apply() or $scope.$digest() inside a function that can be invoked by Angular – e.g. in an ngClick.

The linked Stackoverflow answer has a quick overview of techniques to apply changes to a scope. It also explains what might be wrong when you're getting the error $digest already in progress and gives some information that every Angular developer should know.

Opinionated Angular style guide for teams by @john_papa

Not everything in this guide works perfectly for us, but is still a good start.

You can hook into Slack when using Capistrano for deployment. The slackistrano gem does most of the heavy lifting for you. Its default messages are unobtrusive and can be adjusted easily.

When deploying, it posts to a Slack channel like this:

How to integrate

Integrating Slackistrano with Capistrano 3 is fairly simple.

1. In your Slack, open menu → A...

Often times you want to give a bunch of elements the same style, except for the last. For example borders or margins.

You probably commonly used the :last-child CSS meta selector like so:

.foo {
  border-bottom: 1px dashed #000;
}
.foo:last-child {
  border-bottom-width: 0;
}

However, this only works when an element is the last child of its parent. Any other siblings which are unrelated to your case will break it.

Instead, prefer using the + sibling selector. It applies to the element following the other.

.foo + .foo {
 ...

See this Railscast.

Basically you can simply write views like index.xlsx.erb:

<?xml version="1.0"?>
<Workbook xmlns="urn:schemas-microsoft-com:office:spreadsheet"
  xmlns:o="urn:schemas-microsoft-com:office:office"
  xmlns:x="urn:schemas-microsoft-com:office:excel"
  xmlns:ss="urn:schemas-microsoft-com:office:spreadsheet"
  xmlns:html="http://www.w3.org/TR/REC-html40">
  <Worksheet ss:Name="Sheet1">
    <Table>
      <Row>
        <Cell><Data ss:Type="String">ID</Data></Ce...

Write a // and indent every subsequent line by two spaces.

This is great for documenting BEM blocks!

//
  An action button
  ================
  
  Basic usage
  -----------
  
      <a href="/path" class="action">New booking</a>
      <button class="action">Save</a>
      <input type="submit" class="action">Save</a>
  
  Colors
  -------
  
      <a href="/path" class="action is-red">Primary</a>
      <a href="/path" class="action is-grey">Secondary</a>
  
  Small inline buttons
  --------------------
  
      <p>
        Recor...

When you want to look up a class for a given factory, do it like this:

>> FactoryBot.factories.find('admin').build_class
=> User

In older versions, you could do:

>> FactoryBot.factory_by_name('admin').build_class
=> User

When you use the send_file method to send a local file to the browser, you can save resources on the application server by setting the :x_sendfile option to true. This option is activated by default for Rails 3, so you need to understand this.

What this option does is not to send any data at all, but rather set the local file path as a new response header:

X-Sendfile: /opt/www/awesome-project/shared/downloads/image.png

When the response comes back from Rails to...

Webfonts are not always available when your JavaScript runs on first page load. Since fonts may affect element sizes, you may want to know when fonts have been loaded to trigger some kind of recalculation.

Vanilla JavaScript / Modern DOM API

In modern browsers (all but IE and legacy Edge) you can use document.fonts. Use load to request a font and receive a Promise that will be resolved once the font is available. Example:

document.fonts.load('1rem "Open S...

When a CSS3 animation makes the animated element flicker, it may well be due to pixel fragments being handled differently during animation. You can force the browser into rendering the element on the GPU by adding certain properties. In Chrome, the combination of the following properties has the best effect.

box-shadow: 0 0 0 #000
transform: translate3d(0,0,0) # remember to add vendor prefixes

Depending on your markup, you might need to set these properties on several elements (presumably all those that have height or width in %)...

The debate between using mixins or extends in Sass has been heating up recently. From the surface it appears they both provide solid benefits in helping us write consistent and modular code. However, the critics are out and extends specifically have come under fire. But why?

Interesting results: Although mixins create more code than extends, the gzipped CSS is smaller and somewhat faster to evaluate for current browsers.

Redis comes with a really easy to use Pub/Sub mechanism.