guard-sass compiles or validates your sass (and scss) files automatically when changed.

You will need to have guard to continue, so install it now!

Install the gem with:

gem install guard-sass

Add it to your Gemfile:

gem 'guard-sass', :require => false

And finally add a basic setup to your Guardfile with:

guard init sass

Please read the Guard usage documentation.

guard-sass can be adapted to all kind of projects. Please read the Guard documentation for more information about the Guardfile DSL.

In a Ruby project you want to configure your input and output directories.

guard 'sass', :input => 'sass', :output => 'styles'

If your output directory is the same as the input directory, you can simply skip it:

guard 'sass', :input => 'styles'

With the introduction of the asset pipeline in Rails 3.1 there is no need to compile your Sass stylesheets with this Guard. However, if you would still like to have feedback on the validation of your stylesheets (preferably with a Growl notification) directly after you save a change, then you can still use this Guard and simply skip generation of the output file:

guard 'sass', :input => 'app/assets/stylesheets', :noop => true

This gives you (almost) immediate feedback on whether the changes made are valid, and is much faster than making a subsequent request to your Rails application. If you just want to be notified when an error occurs you can hide the success compilation message:

guard 'sass',
  :input => 'app/assets/stylesheets',
  :noop => true,
  :hide_success => true

Without the asset pipeline you just define an input and output directory as in a normal Ruby project:

guard 'sass', :input => 'app/stylesheets', :output => 'public/stylesheets'

It is standard practice in Rails 3.1 to write sass/scss files with the extension .css.sass to prevent these being written as .css.sass.css you need to set the :extension option like so:

guard 'sass', :input => 'styles', :extension => ''

The following options can be passed to guard-sass:

:input => 'sass'                    # Relative path to the input directory.
                                    # A suffix `/(.+\.s[ac]ss)` will be added to this option.
                                    # default: nil

:output => 'stylesheets'            # Relative path to the output directory.
                                    # default: 'css' or the :input option when supplied

:all_on_start => true               # Compiles all sass files on start
                                    # default: false

:compass => true                    # Enable Compass support with default Rails 3.1-compatible
                                    # options. You can overwrite any of these options by passing
                                    # a hash.

:compass => {
  :images_dir       => "app/assets/images",
  :images_path      => File.join(Dir.pwd, "app/assets/images"),
  :http_images_path => "/assets",
  :http_images_dir  => "/assets",
  :http_fonts_path  => "/assets",
  :http_fonts_dir   => "/assets"
}

:smart_partials => true             # Causes guard-sass to do dependency resolution and only
                                    # recompile the files that need it when you update partials.
                                    # If not on, then guard-sass will update all files when a
                                    # partial is changed.
                                    # default: false

:hide_success => true               # Disable successful compilation messages.
                                    # default: false

:shallow => true                    # Do not create nested output directories.
                                    # default: false

:style => :nested                   # Controls the output style. Accepted options are :nested,
                                    # :compact, :compressed and :expanded
                                    # default: :nested

:load_paths => ['sass/partials']    # Paths for sass to find imported sass files from.
                                    # default: template locations provided by the sass gem

:noop => true                       # No operation: Do not write output file
                                    # default: false

:line_numbers => true               # Add human readable source filname and line number
                                    # information as comments.
                                    # default: false

:debug_info => true                 # File and line number info for FireSass.
                                    # default: false

guard-sass also has a short notation like guard-coffeescript, this lets you define an input folder (with an optional output folder) automatically creating the required watcher.

guard 'sass', :input => 'sass', :output => 'styles'
# or
guard 'sass', :input => 'stylesheets'

These are equivalent to

guard 'sass', :output => 'styles' do
  watch %r{^sass/(.+\.s[ac]ss)$}
end

guard 'sass' do
  watch %r{^stylesheets/(.+\.s[ac]ss)$}
end

By default the guard detects nested directories and writes files into the output directory with the same structure.

The Guard detects by default nested directories and creates these within the output directory. The detection is based on the match of the watch regular expression:

A file

/app/stylesheets/form/button.sass

that has been detected by the watch

watch(%r{^app/stylesheets/(.+\.s[ac]ss)$})

with an output directory of

:output => 'public/stylesheets'

will be compiled to

public/stylesheets/form/button.css

Note the parenthesis around .+\.s[ac]ss. This enables guard-sass to place the full path that was matched inside the parenthesis into the proper output directory.

This behaviour can be switched off by passing the option :shallow => true to the Guard, so that all stylesheets will be compiled directly to the output directory. So the previous example would have compiled to public/stylesheets/button.css.

• Source hosted at GitHub
• Report issues and feature requests to GitHub Issues

Pull requests are very welcome!

For questions please join us on our Google group or on #guard (irc.freenode.net).

Have a look at the GitHub contributor list to see all contributors.

Since this Guard is very close to guard-coffeescript, some features have been incorporated into guard-sass.

(The MIT License)

Copyright (c) 2010 - 2012 Joshua Hawxwell

Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the 'Software'), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED 'AS IS', WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.