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Ruby: A short summary of available hooks in Cucumber

Here is a short summary of Cucumber hooks in Ruby taken from https://github.com/cucumber/cucumber-ruby. Note that the BeforeStep is currently not existing in the Ruby implementation of Cucumber.

Before hooks run before the first step of each scenario.

Before do |scenario|
  ...
end

After hooks run after the last step of each scenario, even when the step result is failed, undefined, pending or skipped.

...

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When you want to format only line breaks, you probably do not want simple_format

For outputting a given String in HTML, you mostly want to replace line breaks with <br> or <p> tags.
You can use simple_format, but it has side effects like keeping some HTML.

If you only care about line breaks, you might be better off using a small, specialized helper method:

def format_linebreaks(text)
  safe_text = h(text)
  paragraphs = split_paragraphs(safe_text).map(&:html_safe)

  html = ''.html_safe
  paragraphs.each do |paragraph|
    html << content_tag(:p, paragraph)
  end

...

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HTML file inputs support picking directories

HTML's <input type="file"> accepts a single file. You can allow multiple files via <input type="file" multiple>.
But sometimes, selecting multiple files is not enough and can be cumbersome for the user. Enter webkitdirectory:

<input type="file" webkitdirectory multiple>

Using webkitdirectory switches the browser's file picker to select a directory. All files inside that directory, and inside any nested subdirectories, will be selected for the file input.

This can be useful when users want to upload all files from a nested dire...

Auto-destruct in 32 days

Spreewald 2.9, 2.99 and 3.0.0 released

Versions 2.9.0, 2.99.0 and 3.0.0 of our gem Spreewald have been released.

2.9.0: Rework email steps

  • The step an email should have been sent with: does now support wildcards (* at the end of a line to ignore the rest of the line, * as single character in a line to ignore multiple lines). The step also has better error messages if an email could not be found.
  • The step show me the emails got an option to display only the email headers. Additionally, a new step `show me the email( header)?s...
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Keeping web applications fast

Our applications not only need to be functional, they need to be fast.

But, to quote Donald Knuth,

premature optimization is the root of all evil (or at least most of it) in programming

The reasoning is that you should not waste your time optimizing code where it does not even matter. However, I believe there are some kinds of optimizations you should do right away, because

  • they are either obvious and easy
  • or they are very hard to do optimize later

This is an attempt to list some of those things:

On the server

...

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What's so hard about PDF text extraction? ​

There is a common view that extracting text from a PDF document should not be too difficult. After all, the text is right there in front of our eyes and humans consume PDF content all the time with great success. Why would it be difficult to automatically extract the text data?

Turns out, much how working with human names is difficult due to numerous edge cases and incorrect assumptions, working with PDFs is difficult due to the extreme flexibility given by the PDF format.

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Simple form examples with bootstrap

Good reference how to build bootstrap forms with simple_form.

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Git: Improve your commits by reviewing changes one-by-one

Git commits should be very deliberate, and only contain changes that you really want to be in there. In order to reduce the chance to accidentally commit something you didn't intend, review your changes before committing.

My preferred way of doing this is (only using git)

git add -N . # Add all paths, but not their contents
git add -p

Git will now show you all your changes in small chunks and ask you in an interactive mode whether you really want to add them.

The most helpful commands are

  • y: yes (add the change)
  • ...
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How to make your application assets cachable in Rails

Note: Modern Rails has two build pipelines, the asset pipeline (or "Sprockets") and Webpacker. The principles below apply for both, but the examples shown are for Sprockets.


Every page in your application uses many assets, such as images, javascripts and stylesheets. Without your intervention, the browser will request these assets again and again on every request. There is no magic in Rails that gives you automatic caching for assets. In fact, if you haven't been paying attention to this, your application is probabl...

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HTML5: disabled vs. readonly form fields

Form fields can be rendered as noneditable by setting the disabled or the readonly attribute. Be aware of the differences:

disabled fields

  • don’t post to the server
  • don’t get focus
  • are skipped while tab navigation
  • available for button, fieldset, input, select, textarea, command, keygen, optgroup, option

Browser specific behavior:

  • IE 11: text inputs that are descendants of a disabled fieldset appear disabled but the user can still interact with them
  • Firefox: selecting text in a disabled text field is no...

RubyMine: Restore main menu in Ubuntu

After a recent Ubuntu update I didn't see the main menu bar of the RubyMine IDE (File | Edit | View | ...) anymore.

This could be solved by changing a RubyMine registry entry:

  • Search "registry" within the "Actions" search
    • press ctrl + alt + n > click on Actions > type registry > click on Registry...
  • Scroll down to linux.native.menu and disable the checkbox

After rebooting RubyMine, you'll have gotten the menu bar back.

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Stretching an HTML page to full height

This card existed before, but was outdated due to browser implementation changes. The information below is validated for the current list of browsers we support.


By default your html and body elements are only as high as the actual page content. If you only have two lines of text in your page, your html and body elements will only be around 40 pixels high, regardless of the size of your browser window.

You might be surprised by this, since setting a background on either html and body does cover the enti...

Vortrag: Content Security Policy: Eine Einführung

Grundidee

CSP hat zum Ziel einen Browser-seitigen Mechanismus zu schaffen um einige Angriffe auf Webseiten zu verhindern, hauptsächlich XSS-Angriffe.

Einschub: Was ist XSS?

XSS = Cross Site Scripting. Passiert wenn ein User ungefiltertes HTML in die Webseite einfügen kann.

<div class="comment">
  Danke für den interessanten Beitrag! <script>alert('you have been hacked')</script>
</div>

Rails löst das Problem weitgehend, aber

  • Programmierfehler weiter möglich
  • manchmal Sicherheitslücken in Gems oder Rails

Lösungsid...

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HTML forms with multiple submit buttons

Most forms have a single submit button that will save the record when pressed.

Sometimes a form needs additional submit buttons like "accept" or "reject". Such buttons usually attempt a state transition while updating the record.

To process a form with multiple buttons, your server-side code will need to know which button was pressed. To do so you can give each submit button a different [formaction] attribute. This will override the ...

How to prevent Nokogiri from fixing invalid HTML

Nokogiri is great. It will even fix invalid HTML for you, like a browser would (e.g. move block elements out of parents which are specified to not allow them).

>> Nokogiri::HTML.fragment("<h1><p>foo</p><span>bar</span></h1>").to_s
=> "<h1></h1><p>foo</p><span>bar</span>"

While this is mostly useful, browsers are actually fine with a bit of badly formatted HTML. And you don't want to be the one to blame when the SEO guy complains about an empty <h1>.

To avoid said behavior, use Nokogiri::XML instead of Nokogiri::HTML when par...

The HTML5 video element

# Basic HTML example
<video poster="preview_image.png" controls>
  <source src="or_here.webm" type="video/webm" />
  <source src="alternative_if_browser_cant_pay_first_source.mp4" type="video/mp4" />
  <track src="optional_subtitles.vtt" kind="subtitles" srclang="de" label="Deutsch" default>
</video>

# Javascript API (notable methods and properties)
video = document.querySelector('video')
video.play()
video.pause()
video.load() // Reset to the beginning and select the best available source
video.currentSrc // The selected source
video.c...

The JavaScript Object Model: A deep dive into prototypes and properties

Speaker today is Henning Koch, Head of Development at makandra.

This talk will be in German with English slides.

Introduction

As web developers we work with JavaScript every day, even when our backend code uses another language. While we've become quite adept with JavaScript at a basic level, I think many of us lack a deep understanding of the JavaScript object model and its capabilities.

Some of the questions we will answer in this talk:

  • How does the new keyword construct an object?
  • What is the differen...
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Test Driven Development with Cucumber and RSpec

Test Driven Development is the paradigm to "first write a test, then implement the code". This guide shows how to apply it in practice, with Cucumber and RSpec as integration and unit test frameworks.

Hierarchical approach

I like to view TDD as a process with three levels:

  • Cucumber level (integration test)
  • Code level
  • RSpec level (unit test)

During development you are frequently changing levels. It may look something like this:

Integration _                    _
Code         \__      ___     __/
Spec            \____/   \__...
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