If you're supporting IE9+, you can listen to input to see if a text field changes.

Other than change, it fires while the user is typing and doesn't wait until the user blurs the fie...

Let's say we have posts with an attribute title that is mandatory.

Our example feature request is to tag these posts with a limited number of tags. The following chapters explain different approaches in Rails, how you can assign such a...

validates_uniqueness_of is not sufficient to ensure the uniqueness of a value. The reason for this is that in production, multiple worker processes can cause race conditions:

1. Two concurrent requests try to create a user with the same name (a...

Jasmine has long standing support for writing asynchronous specs. In days gone by we used the done callback to achieve this, but these days it is possible to write much more readable specs.

Async specs

As a first example, say we want to chec...

Find conditions for scopes can be given either as an array (:conditions => ['state = ?', 'draft']) or a hash (:conditions => { 'state' => 'draft' }). The later is nicer to read, but has horrible security implications in some versions of Ru...

Occasionally you need to do something directly on the server -- like having all records recalculate something that cannot be done in a migration because it takes a long time.

Let's say you do something like this:

Project.all.each(&:recal...

Slides for Henning's talk on Sep 21st 2017.

Understanding sync vs. async control flow

Talking to synchronous (or "blocking") API

print('script start')
html = get('/foo')
print(html)
print('s...

If you get an error message like that you are missing the Aspell files a specific language:

No word lists can be found for the language "de"

Solve it by installing the proper package, e.g. on Ubuntu:

sudo apt-get install aspell-de

Capybara has a variety of finder methods like find_button to help you look up DOM elements. There are also matchers ...