If - for whatever reason - you have to render stylesheets dynamically, the following snippet might be of help. It emulates what "sprockets" would to when precompiling your assets, and give your stylesheets access to all the regular bells and whistles (like asset_path, proper @imports etc):

class DynamicStylesheetsController < ApplicationController

    def show
      logical_path = RELATIVE_PATH_TO_YOUR_TEMPLATE
      path = File.join(Rails.root, logical_path)
      template = Sass::Rails::SassTemplate.new(path)
      environment = ...

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 --intent-to-add . # Add all paths (including new files), 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 ...

If some AJAX functionality does not work, but you see Firefox making an OPTIONS request, the reasons is most likely this:

You're accidently trying to talk to a different domain (or switching from http to https), and Firefox tries to find out if that is okay, according to the "Cross-Origin Resource Sharing" standard.

You know that you can force absolute URLs throughout a response. Now you want to modify URLs similarly, but only in parts of a view (or controller) logic. Here is how.

Note: this has only been tested on a Rails 2 application. It should work similarly for Rails 3.

Put this into your ApplicationController:

def rewrite_options(*args)
  options = super
  options.merge!(:only_path => false) if @with_full_urls
  options
end...

Capybara uses www.example.com as the default hostname when making requests.
If your application does something specific on certain hostnames and you want to test this in a feature, you need to tell Capybara to assume a different host.

Given /^our host is "([^\"]+)"$/ do |host|
  page.config.stub app_host: "http://#{host}"
  
  # In older Capybaras (< 2.15) you needed to do this instead:
  Capybara.stub app_host: "http://#{host}"
end

You can now say:

When I go to the start page
Then I should not see "Home ...

The gem author Jonas Nicklas highlights in a Google Groups post that the release

• is not backwards compatible to 1.x versions of Capybara
• does not support Ruby 1.8.x anymore
• removes confusion with Rails' built in integration tests (you put capybara rspec integration tests into the spec/feature/... folder) and the :type metadata has been changed from :request to :feature
• throws exceptions when trying to interact with an element whose identifier is...

Since I use this a lot in my daily work and there were no scripts working properly for me, I made one myself.
It's actually not bound to Xfce but should work on any window manager (haven't tried it, though).

Installation

1. If you don't yet have xdotool, install it:

   sudo apt-get install xdotool
   

2. If you don't yet have wmctrl, install it:

   sudo apt-get install wmctrl
   

3. Store the attached file in some place that's in your PATH.
   The cool kids use ~/bin/.

4. Make it executable: `chmod +x ~/bin/move-to-next-mo...

You can use scheme-less URLs (or protocol-relative URLs) to have browsers use the current protocol (HTTP or HTTPS) when loading content referenced with such an URL.

A protocol relative URL doesn’t contain a protocol. For example, http://stevesouders.com/images/book-84x110.jpg becomes //stevesouders.com/images/book-84x110.jpg

Browsers substitute the protocol of the page itself for the resource’s missing protocol. Problem solved!

But:

Internet Explorer 7 & 8 will download st...

Having your site run on SSL is worthless when you include content over an unsafe connection (HTTP).

Here is how to hunt down mixed content with Firefox.

How to enable mixed content alerts

If your Firefox does not warn you about mixed content on pages (mine did not), you can enable it again:

Visit about:config and search for security.warn_viewing_mixed. If it's set to false, set it back to true again.

Seeing which URLs are fetched from unsecured connections

Firefox 16+ will show you mixed content in its "Web Console".
Open it ...

url = 'http://www.foocorp.com/foo/bar'
URI.parse(url).host
# => www.foocorp.com

Note that this will raise an error if the given argument is not a URL.

If you need the host's full URL without path, query, fragment etc., use URI.join with a clever twist:

url = 'http://www.foocorp.com:33546/foo/bar?query=foobar#hash'
URI.join url, '/'
# => http://www.foocorp.com:33546/

In a nutshell:

If you require your Rails models manually, pay attention to the path you use. Unless you have to, don't do it at all.

Background

Consider these classes:

# app/models/user.rb

class User < ActiveRecord::Base
  validate :magic

  def magic
    errors.add_to_base('failed') if bad_things?
  end
end

^
# app/models/foo.rb

require 'user'

class Foo
  # something happens here
end

Now, when your environment is booted, Rails will automatically load your models, like User...

Example task: Multiply the table holidays between several stages.

1. Open two terminals:

   shell-for stage_1
   shell-for stage_2
   

2. Get the stage1 and stage2 MySQL credentials:

   cat /opt/www/the_stage.host.tld/current/config/database.yml
   cat config/database.yml # should do it
   

3. Dump the table to a path reachable by the stage2 user (e.g. home):

   mysqldump -h mysql1 -u stage_1_user -p stage_1_database table_name > ~/table_name_dump.mysql # Select certain records using --where "some_id > 666"
   

   (-...

to_file has been removed in Paperclip 3.0.1.

Instead of using File to access Paperclip storage objects (like this: File.read(file.to_file.path)) you can use

Paperclip.io_adapters.for(file).read

Today I got a better understanding of how git works, in particular what git checkout and git reset do.

Git basics

• A commit holds a certain state of a directory and a pointer to its antecedent commit.
• A commit is identified by a so-called ref looking something like 7153617ff70e716e229a823cdd205ebb13fa314d.
• HEAD is a pointer that is always pointing at the commit you are currently working on. Usually, it is pointing to a branch which is pointing to that commit.
• Branches are nothing but pointers to commits. Y...

Given you store files on Amazon S3 and you need to stream those files out to people while you don't want them to be able to distribute the content simply by sharing the S3 URL.

You could either mark the bucket as private and fetch the appropriate files from S3 to your application server and stream them to the client finally. While this is possible, I'd recommend to use what AWS calls "Query String Authentication".

If you're using Paperclip you can chose between two sto...

Ever wanted autocompletion for paths from paths.rb in Cucumber? This card lets you write your steps like this:

When I go to path *press tab now* # path is replaced with a list of all known Cucumber paths

This is how you do it

(key shortcuts apply for TextMate2)

1. Open the bundle editor (ctrl + alt +  + B)

2. Create a new Item ( + N), select "Command"

3. Paste this:
   ^
   #!/usr/bin/env ruby -wKU
   require File.join(ENV['TM_SUPPORT_PATH'], 'lib', 'ui.rb')

   cucumber_paths = File.join ENV['TM_PROJECT_DIRECTORY'], 'features'...

StaticMatic is a nice tool to build simple static websites.
In case you want to have some nifty styles on the navigation item that is currently active, you can use this:

=link 'Aktuelles', :class => (current_page =~ /aktuelles/) ? 'current' : 'default'

Keep in mind that current_page gives you the full relative path of your page. raise current_path in case you're not sure.

I know there is an navigation helper out there. I did not use it and also did not want to migrate.

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...

When you get an error like this:

Invalid gemspec in [/opt/www/foo-project.makandra.de/shared/bundle/ruby/1.8/specifications/carrierwave-0.6.2.gemspec]: Illformed requirement ["#<YAML::Syck::DefaultKey:0x7fda6f84d2e8> 1.1.4"]

... the machine's Rubygems needs to be updated.

If that happens on your local machine

• Manually remove the offending's gem files and specifications. The paths will be something like /usr/lib/ruby/gems/1.8/gems/your-broken-gem and `/usr/lib/ruby/gems/1.8/specificatio...

We frequently use the handy Paperclip Gem to manage file attachments.

If you need to move the files from local storage (i.e., your servers' harddisk) to Amazon S3, you can simply change settings for Paperclip to use the S3 storage adapter and use this script to migrate to S3. Put the snippet into a chore if you don't want to run that in the console.
YOUR_LOCAL_STORAGE_MODEL_DIRECTORY should be something like 'storage/your_model'.

Dir.glob(YOUR_LOCAL_STORAGE_MODEL_DIRECTORY**/*).each do |path|...

If you get errors from your development WEBrick that contain unicode salad, you are probably requesting the page via SSL. \
Since WEBrick does not speak SSL, so change the URL in your browser to use http instead of https.

The error looked like this for me:

[2012-09-06 11:19:07] ERROR bad URI `\000\026\000\020\000'.
[2012-09-06 11:19:07] ERROR bad URI `\000\026\000\020\000'.
[2012-09-06 11:19:07] ERROR bad Request-Line `\026\003\001\000�\001\000\000\177\003\001PHj�\031\006�L��'.
[2012-09-06 11:19:07] ERROR bad URI `\000\026\000\...