RaphaelJS: A Javascript vector graphics library

Raphaël is a small JavaScript library that should simplify your work with vector graphics on the web. If you want to create your own specific chart or image crop and rotate widget, for example, you can achieve it simply and easily with this library.

7 Rules for Creating Gorgeous UI

A great two-part article about various hacks you can use to create great-looking screen designers when you're not a designer.

Part 1 contains:

  • Light comes from the sky
  • Black and white first
  • Double your whitespace

Part 2 contains:

  • Learn the methods of overlaying text on images
  • Make text pop— and un-pop
  • Only use good fonts
  • Steal like an artist

bower-rails can rewrite your relative asset paths

The asset pipeline changes the paths of CSS files during precompilation. This opens a world of pain when CSS files reference images (like jQuery UI) or fonts (like webfont kits from Font Squirrel), since all those url(images/icon.png) will now point to a broken path.

In the past we have been using the vendor/asset-libs folder ...

HTML5: Allow to choose multiple files with a vanilla file picker

Modern browsers natively suppport file pickers that allow the user to choose multiple files at once. To activate this feature, set the multiple attribute:

<input type="file" name="images[]" multiple />

Or in a Rails view:

<%= file_field_tag "images[]", multiple: true %>

This works in IE10+.

Make sure that the field name ends in [] so your server-side code will parse the incoming files into an array. Obviously this naming convention is not compatible with default Rails nested attribute setters, so you'll need to write a form ...

Eager-loading polymorphic associations

To avoid n+1 queries, you want to eager-load associated records if you know you need to access them later on.

The Rails docs say:

Eager loading is supported with polymorphic associations.

This is true, but has some caveats.

Example

Consider the following models:

class Image < ActiveRecord::Base; end
class Video < ActiveRecord::Base; end
class PageVersion < ActiveRecord::Base
  belongs_to :primary_medium, polymorphic: true # may be Image or Video
end
class Page < ActiveRecord::Base
  belongs_to ...

Git: Diff per word or character

By default git diff highlights whole lines as changes.

To diff on a word-by-word basis you can say:

git diff --color-words

To diff on a character-by-character basis you can say:

git diff --color-words=.

Paperdragon: Explicit Image Processing

It's like Paperclip or CarrierWave, but without any automagic integration.

What we know about PDFKit

What PDFKit is

  • PDFKit converts a web page to a PDF document. It uses a Webkit engine under the hood.
  • For you as a web developer this means you can keep using the technology you are familar with and don't need to learn LaTeX. All you need is a pretty print-stylesheet.

How to use it from your Rails application

  • You can have PDFKit render a website by simply calling PDFKit.new('http://google.com').to_file('google.pdf'). You can then send the...

Do not use transparent PNGs for iOS favicons

Safari on iOS accepts an apple-touch-icon favicon that is used for stuff like desktop bookmarks. Always define a solid background color for them.

If you use PNGs with a transparent background, Safari will use just set a black background on your pretty icon. This is almost never what you want.
You can fix that by applying a white background via ImageMagick like this:

convert a...

Sass function to set a color to an absolute hue

The adjust-hue function of Sass allows you to change a color's hue, but only relative to its current hue.

adjust-hue(#ffff00, 120)
// => #00ffff
adjust-hue(#444400, 120)
// => #004444

As you can see, we moved our yellow by 120° to cyan. \
But what if you want to move any color to a hue of 120° which is a nice shiny green?

Take this function:

@function set-hue($color, $target-hue)
  $current-hue: hue($color)
  $degree...

SudoSlider: a jQuery slider

SudoSlider is a simple yet powerful content slider that makes no (or very few) assumptions about your markup and is very customizable.

You can basically embed any HTML into the slides, so you can mix images, videos, texts, and other stuff.

Check out the demos.

Please note:

  • There is a ton to configure. Check the demos and read the docs.
  • It does not bring styles for prev/next links etc, so you need to style controls yourself (which I consider to b...

If Guard takes forever to start...

For me guard recently took a very long to start (as in "minutes"), because I had lots of images in public/system.

Upgrading the listen gem (which is a dependency) to 2.7.7 fixed this.

Offtopic: Floppy-disc OS

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...

Hash any Ruby object into an RGB color

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.

How to force a client-side refresh on a new favicon

Browsers usually cache favicons. If you update the favicon of your web site and want all visitors to see the new icon, you need to give the icon a different URL. You will not have this issue if you cache your assets properly, which appends a fingerprint to your image URL (like favicon.ico?432423432):

<link href="<%= image_path('favicon.ico') %>" rel="icon" type="image/vnd.microsoft.icon">

faviconit.com: Super-simple favicon generator

Eduardo Russo was tired of complex favicon creation and created his own favicon generator. It's really easy and allows a lot of image editing before rendering the favicons, in all needed sizes, formats and with the HTML needed to include them!

In Rails applications with Haml:

  • put all the favicon files into /public
  • store the HTML to app/views/layouts/_favicon.html
  • add = render 'layouts/favicon' to <head> in your application layout(s)

... and you're all...

RulersGuides.js demo

RulersGuides.js is a Javascript library which enables Photoshop-like rulers and guides interface on a web page

Also available as a bookmarklet.

pngquant — lossy PNG compressor

pngquant is a command-line utility and a library for converting 24/32-bit PNG images to paletted (8-bit) PNGs.

The conversion reduces file sizes significantly (often as much as 70%) and preserves full alpha transparency.

Embed Font Awesome icons from your CSS

An annoying part of using font icons is that the icons usually need to live in the DOM. This is a step back from the time when we defined raster icons with background-image, in the CSS.

It doesn't have to be that way.

Copy the attached file font-awesome-sass.css.sass to your assets (we recommend /vendor/asset-libs/font-awesome-sass).

You can now use Font Awesome icons from your Sass files:

@import font-awesome-sass

...

Ruby constant lookup: The good, the bad and the ugly

In Ruby, classes and modules are called constants. This card explains how Ruby resolves the meaning of a constant.

The good

E. g. in the following example, Array could mean either Foo::Array or simply Array:

class Foo
  def list
    Array.new
  end
end

What Ruby does here is to see if the name Array makes sense inside of Foo::, and if that fails, resolves it to ::Array (without a namespace).

The bad

This is relevant for old Ruby versions. Ruby 2.5+ removes top-level constant lookup whi...

CarrierWave: Don't use #url when you mean a file path

CarrierWave attachments have two distinct methods #url and #path which appear to behave the same:

document.file.url   # => /storage/documents/4/letter.doc
document.file.path  # => /storage/documents/4/letter.doc

However, starting with CarrierWave 0.9, #url will properly escape high-ASCII characters:

document.file.url   # => /storage/documents/4/h%C3%BCte.doc
document.file.path  # => /storage/documents/4/hüte.doc

So always use #url if you mean an actual URL (e.g. to display an <img>). But use #path if y...

Howto provide a single page preview for PDF & TXT with carrierwave

Assert rmagick provision ...

Gemfile

gem 'rmagick', '2.13.2' # at this moment the latest stable version

config/initializer/carrierwave.rb

require 'carrierwave/processing/rmagick'

... and define a custom processor

MyUploader.rb

class MyUploader < CarrierWave::Uploader::Base
  include CarrierWave::RMagick

  def cover
    manipulate! do |frame, index|
      frame if index.zero? # take only the first page of the file
    end
  end

  version :preview do
    process :cover
    process :resize_to_fit => [310,...

Spreewald 0.8.0 brings a file attachment step

# Attach a file
#
# Example:
#
#   Company.new.logo = File.new…
#
#   Given the file "…" was attached as logo to the company above
#
#
# Example:
#
#   class Gallery
#     has_many :images, :as => :owner
#   end
#
#   class Image
#     belongs_to :owner, polymorphic: true
#   end
#
#   # so container = Image.new; container.file = File.new… , container.owner = object
#
#   Given the file "…" was attached as Image/file to the company above
#
#
# Example:
#
#   Set updated_at with
#
#     Given … above at "2011-11-11 11:11"
#