I got these warnings while deploying a Rails 3.2 app with asset pipeline enabled:

*** [err :: host.tld] find: `/opt/www/hollyapp.com/releases/20120503115342/public/images': No such file or directory
*** [err :: host.tld] find: `/opt/www/hollyapp.com/releases/20120503115342/public/stylesheets': No such file or directory
*** [err :: host.tld] find: `/opt/www/hollyapp.com/releases/20120503115342/public/javascripts': No such file or directory

Folders like public/javascripts might not exist if you're using the asset pipeline (...

You can use this code:

function scrollToLine($textarea, lineNumber) {
  var lineHeight = parseInt($textarea.css('line-height'));
  $textarea.scrollTop(lineNumber * lineHeight);      
}

Some caveats about this code:

1. Your textarea needs to have a line-height in Pixels.
2. The code will scroll to the line number in the text area, not the line number of the original text. These will differ if any lines wrap at the edge of the textarea.

Also see our solution for [scrolling a textarea to a given position with jQuery](htt...

Controller responses often include Javascript code that contains values from Ruby variables. E.g. you want to call a Javascript function foo(...) with the argument stored in the Ruby variable @foo. You can do this by using ERB tags (<%= ruby_expression %>) or, in Haml, interpolation syntax (#{ruby_expression}).

In any case you will take care of proper quoting and escaping of quotes, line feeds, etc. A convenient way to do this is to use Object#json, which is defined for Ruby strings, numb...

In your ~/.gitconfig:

[core]
  editor=nano

So you probably see the following error trace within your Passenger log file if you got here:

[ pid=123 thr=1401414 file=ext/nginx/HelperAgent.cpp:964 time=2012-04-27 10:01:49.273 ]: Uncaught exception in PassengerServer client thread:
   exception: Cannot accept new connection: Too many open files (24)
   backtrace:
     in 'Passenger::FileDescriptor Client::acceptConnection()' (HelperAgent.cpp:429)
     in 'void Client::threadMain()' (HelperAgent.cpp:953)

You can either

1. Lower the maximum number of running Passenge...

zClip is a lightweight jQuery "copy to clipboard" plugin built using the popular Zero Clipboard library. This plugin uses an invisible Adobe Flash movie that is fully compatible with Flash Player 10 and below.

A small library to provide the Rails I18n translations in Javascript clients.

CodeMirror is a JavaScript component that provides a code editor in the browser. When a mode is available for the language you are coding in, it will color your code, and optionally help with indentation.

xterm by default uses black text on white background.

To change that to something like "light gray on black", do a

vim ~/.Xresources

...and put this in there:

xterm*background: black
xterm*foreground: lightgray

Afterwards, feed these changes to your current X session:

xrdb ~/.Xresources

Any subsequent xterm will be colored white on black background.

Hint:

• While you're at it, you can also set xterm's font in your ~/.Xresources file. Just add xterm*faceName: monospace:pixelsize=14.
• If you don't want to chan...

This is for you if Passenger gives you the following useless error message.

Passenger encountered the following error:\
The application spawner server exited unexpectedly: Unexpected end-of-file detected.

Exception class:
: PhusionPassenger::Rack::ApplicationSpawner::Error

Most often this happens because you are missing a gem. Usually Passenger would tell you about that but in some cases it can't.

To resolve this issue, run:

bundle install

If this does not do the trick for you, take a look at the Apache log files for de...

Make sure you call the methods in the following order and not vice versa:

has_attached_file :image
validates_attachment_presence :image

Validation with condition works fine, too:

validates_attachment_presence :image, :if => :method

This is because validates_attachment_presence is only available after saying has_attached_file.

The default behavior of Calc is that when you paste cells from the clipboard, it overwrites whatever cells occupy the same space on the spreadsheet. If you would like to insert the cells in the clipboard instead by pushing the existing cells to the bottom or the right, you can do it like this:

• Go to Edit / Paste Special
• The paste dialog has a segment Shift Cells. Choose Down or Right depending on what you want to do.

If you cannot install the gem 'RedCloth' via bundle install you might want to try the following.

Specifying extra build options for bundler which will only be applied when building RedCloth:

bundle config build.RedCloth --with-cflags=-w

An = is represented by =3D in the log file.

I got confused by the leading 3D which is not part of the token, you can see in the following example:

Hallo Max!

Danke f=C3=BCr deinen Beitrag. Bitte best=C3=A4tige deine Teilnahme, inde=
m du auf den folgenden Link klickst:

  http://localhost:3000/beitraege/13/confirm?token=3DEA7BB9DA73FF17AO

Viele Gr=C3=BC=C3=9Fe vom Team!

My token is actually only EA7BB9DA73FF17AO.

Geordi, our collection of command line tools, has been extended by another command deploy-to-production. This script encapsulates the following workflow:

• Pull the production branch.
• Show which commits from the master would make it to production with this deploy.
• Ask if you want to proceed.
• If yes, merge the master into the production branch, push and deploy with bundle exec cap production deploy:migrations

The script will ask you for the names of your master branch, production branch an...

• You can define what will be printed by checking View -> Preview Page Breaks and then moving around the blue borders.
• You can now define the size of the printed content under Format -> Page -> Sheet -> Scale. You can choose between three scaling modes which all suck in their own way.

After installing Bundler 1.1 you will get the following warning when running tests:

WARNING: Cucumber-rails required outside of env.rb. The rest of loading is being defered until env.rb is called.\
To avoid this warning, move 'gem cucumber-rails' under only group :test in your Gemfile

The warning is misleading because it has nothing to do with moving cucumber-rails into a :test group. Instead you need to change your Gemfile to say:

gem 'cucumber-rails', :require => false

Solution to share a todo.txt file over Dropbox and make it editable on Android und iOS devices. Also comes with a CLI interface for common actions like adding a new task or listing all tasks pertaining to a GTD context.

Unfortunately it only supports flat todo lists, no nesting.

validates_acceptance_of :terms only works if terms is set to a value. The validation is skipped silently when terms is nil.

While this behavior is useful to validate acceptance in the frontend and not the admin backend, it also makes it very easy to unintentionally skip the validation altogether by forgetting to add the checkbox to a form. E.g. validates_acceptance_of :terms_with_typo will be skipped silently even if there is no column with t...

When you create a new branch and push it to origin, you won't be tracking it. This means a git pull won't know its remote version.

You could use difficult commands to set up a branch's tracking but it's easier to just push it like this:

git push -u

From the documentation on git push:

-u, --set-upstream
For every branch that is up to date or successfully pushed, add upstream (tracking) reference, used by argument-less git-pull(1) and other commands. For more information, see branch.<nam...

You won't usually have to do this. It's OK to route all formats to a controller, and let the controller decide to which format it wants to respond.

Should you for some reason want to define a route that only responds to a given format, here is how you do it:

Rails 3

match 'sitemap.xml' => 'feeds#sitemap', :constraints => { :format => 'xml' }, :as => 'sitemap'

Rails 2

map.sitemap 'sitemap.xml', :controller => 'feeds', :action => 'sitemap', :format => 'xml'

When talking to your MySQL server via a mysql shell, you can terminate queries by ; or \G -- the latter gives you a vertical output.

You know this:

mysql> SELECT * FROM users;
+----+---------+---------------------+-----------------+
| id | name    | email               | greeting        |
+----+---------+---------------------+-----------------+
|  1 | Alice   | alice@example.com   | Hello world!    |
|  2 | Bob     | bob@example.com     | Hello universe! |
|  3 | Charlie | charlie@example.com | Hi mom!    ...

This is a demo of the "Tabby" Javascript jQuery plugin to use tabs in regular textareas to make them suitable for in-browser coding of languages like HTML, CSS, Javascript, or your favorite server-side language. The idea is to be able to use a press of the TAB button or SHIFT+TAB to indent or outdent your code.

This will give you the string that appears most often in an array:

names = %w[ foo foo bar bar bar baz ]
names.group_by(&:to_s).values.max_by(&:size).try(:first)
=> "bar"

This is very similar to the linked StackOverflow thread, but does not break on empty arrays.

Note that try is provided by ActiveSupport (Rails). You could explicitly load activesupport or use andand on plain Ruby.