If a controller action responds to other formats than HTML (XML, PDF, Excel, JSON, ...), you can reach that code in a controller spec like this:

describe UsersController do
  describe '#index' do
    it 'should be able to send an excel file' do
       # stubs and expectations go here
       get :index, :format => 'xls'
    end
  end
end

Remember that both the :format parameter and the HTTP_ACCEPT header can m...

In rare cases you might need something like form_for (for using form builder methods on the resulting block element) but without the surrounding form. One such case would be updating some of a form's fields via XHR.

You can simply use Rails' fields_for to do things like this in your views (HAML here):

- fields_for @user do |form|
  = form.label :email, 'E-Mail'
  = form.text_field :email

You will only receive the form content you gave, no hidden inputs incl...

When using form_for you can give the form's target URL either as a string or an array:

form_for(admin_user_path(@user)) do ... end
# same as:
form_for([:admin, @user]) do ... end

Same for link_to:

link_to("Label", edit_admin_user_path(@user))
# same as
link_to("Label", [:edit, :admin, @user])

polymorphic_path and polymorphic_url

If you would like to generate a path or URL string from an array of route components just as form_for does, you can use polymorphic_path or polymorphic_url:

polymorphic...

Sometimes the order in which strings appear on a page matters to you.

Spreewald gives you steps like these:

Then I should see in this order:
  | Alpha Group |
  | Augsburg    |
  | Berlin      |
  | Beta Group  |

Or, if you prefer multiline strings:

Then I should see in this order:
  """
  Alpha Group
  Augsburg
  Berlin
  Beta Group
  """

The step ignores all HTML tags and only tests on plain text.

If you have several submit elements (inputs or buttons with type="submit") that each cause different things to happen (e.g. you might have a button that sends an extra attribute) you might run into trouble when submitting the form by pressing the return key in a field.

When nothing fancy like a tabindex is defined it seems as if the first submit element inside a form is chosen (and has its attributes submitted) when pressing return.\
So, if possible, put your "default" (aka least harmful) submit element before others.

NB: If you s...

1. In /etc/crontab
2. In /etc/cron.d/*
3. In /etc/cron.hourly/*
4. In /etc/cron.daily/*
5. In /etc/cron.weekly/*
6. In /etc/cron.monthly/*
7. In the personal crontab of any user. This is a magic file you can view with crontab -l and edit with crontab -e. You'll need to su to the respective user to view or edit her crontab.

You don't need a Rails application to use Sass. Even when you're working on a static site you can generate your CSS through Sass.

• Install Sass with sudo gem install haml
• Create a folder sass in the folder, that stores your stylesheets, e.g. mkdir css/sass
• In a separate terminal window, run sass --watch css/sass:css. This will watch your sass files for changes and rewrite stylesheets as required.

This even works on Windows.

Note about your .gitignore

You might want to change our [typical .gitignor...

For some reason you want to define a find condition in array form. And in that condition both column name and value are coming from user input and need to be sanitized.

Unfortunately this works in SQLite but does not in MySQL:

named_scope :filter, lambda { |attribute, value|
  { :conditions => [ 'articles.? = ?', attribute, value ] }
}

The solution is to use [sanitize_sql_array](http://apidock.com/rails/ActiveRecord/Base/sa...

When using virtual attributes, the attached trait can be useful to automatically copy errors from one attribute to another.

Here is a typical use case where Paperclip creates a virtual attribute :attachment, but there are validations on both :attachment and :attachment_file_name. If the form has a file picker on :attachment, you would like to highlight it with errors from any attribute:

class Note < ActiveRecord::Base
  has_attached_file :attachment
  validates_attachment_presence :a...

When Paperclip attachments should only be downloadable for selected users, there are three ways to go.
The same applies to files in Carrierwave.

1. Deliver attachments through Rails

The first way is to store Paperclip attachments not in the default public/system, but in a private path like storage inside the current release. You should prefer this method when dealing with sensitive data.

Make ...

This will show you how to create a RSS feed that the Feed Validator considers valid.

Note that RSS is a poorly specified format. Consider using the Atom builder to make an Atom feed instead. Write a note here if you do.

1. Controller

Create a FeedsController to host the RSS feed. Such a controller is also useful to host other data feeds that tend to gather over the lifetime of an application, e.g. sitemap.xml.:

class...

If you want to rename a key of a Ruby hash, this could help you out.
Just put it into something like config/initializers/hash_move.rb.

In a great post about named routes in Rails, path vs. url, Viget Labs ponders which variant is best used.<br />
<br />
Most often we use foo_path, which when used in Rails URL helpers will generate a relative path, where foo_url generates a full URL. In most cases the path makes most sense, but not always.

This post explains, in some detail, how we will implement a nice performance boost for Rails developers. Understanding the details might help gain the full benefits of the optimization, but you will gain some benefits even if you have no idea how it works.

WMD is a simple, lightweight HTML editor for blog comments, forum posts, and basic content management. You can add WMD to any textarea with one line of code. Add live preview with one line more. WMD works in nearly all modern browsers, and is now completely free to use.

Expiration of Rails sessions

By default Rails sessions expire when the user closes her browser window.

To change this edit your config/initializers/session_store.rb like this:

ActionController::Base.session = {
  :key          => '...',
  :secret       => '...'
  :expire_after => 10.years
}

In older Railses the initializer is not available. Set the option in the environment.rb instead:

config.action_controller.session = {
  :key          => '...',
  :secret       => '...'

...

The following Haml will do:

%head{ :profile => 'http://www.w3.org/2005/10/profile' }
  %link{ :href => image_path('favicon.ico'), :rel => 'icon', :type => 'image/vnd.microsoft.icon' }

Note that while you can link to icon formats other than .ico, Internet Explorer is too stupid for that.

There are two distinct ways of commenting Haml markup: HTML and Ruby.

HTML comments

This will create an HTML comment that will be sent to the client (aka browser):

/= link_to 'Example', 'www.example.com'

This produces the following HTML:

<!-- = link_to 'Example', 'www.example.com' -->

Only use this variant if you need the comment to appear in the HTML.

Ruby comments

This will comment code so it will not be sent to the client:

-# = link_to 'foo'

99% of the time you'll be adding notes f...

This is an awesome gadget in your toolbox, even if your test coverage is great.

• gem install ruby-debug (Ruby 1.8) or gem install debugger (Ruby 1.9)
• Start your server with script/server --debugger
• Set a breakpoint by invoking debugger anywhere in your code
• Open your application in the browser and run the code path that crosses the breakpoint
• Once you reach the breakpoint, the page loading will seem to "hang".
• Switch to the shell you started the server with. That shell will be running an irb session where you can step thr...

To return non-HTML responses (like XLS spreadsheets), we usually use the

respond_to do |format|
  format.xls do
    # send spreadsheet
  end
end

This is often, but not always the same as checking for params[:format] == :xls, so don't rely on this when e.g. one format checks for authorization and the other doesn't.

params[:format] is only set when a user explicitly puts a .xls at the end of the URL.

The format.xls block also responds when the user's browser requests the application/excel MIME type.

If Internet Explo...

Update RubyGems and Passenger

Bundler requires Rubygems >= 1.3.6. Run gem update --system if you have an older version.
It also is not compatible with older versions of passenger, so bring that up to date as well (2.2.15 works).

If you installed RubyGems through apt (which you should never do!), you may see a message giving you a hint to use apt to update.
Some people advise to install the 'rubygems-update-1.3.7' gem on Ubuntu systems if you used apt to install RubyGems.
I did that - and lost all...

Sometimes files attain executable-flags that they do not need, e.g. when your Windows VM copies them over a Samba share onto your machine.

From inside your Rails project directory call regularly:

geordi remove-executable-flags

Runs chmod -x on Ruby, HTML, CSS, image, Rake and similar files.

This script is part of our geordi gem on github.