NAME - perl bindings for libsass¶

CSS::Sass - Compile .scss files using libsass

SYNOPSIS¶

  # Object Oriented API
  use CSS::Sass;
  # Call default constructor
  my $sass = CSS::Sass->new;
  # Manipulate options for compile calls
  $sass->options->{source_comments} = 1;
  # Call file compilation (may die on errors)
  my $css = $sass->compile_file('styles.scss');
  # Add custom function to use inside your Sass code
  sub foobar { CSS::Sass::Value::String->new('blue') }
  $sass->options->{sass_functions}->{'foobar'} = \ &foobar;
  # Compile string and get css output and source-map json
  $sass->options->{source_map_file} = 'output.css.map';
  ($css, $stats) = $sass->compile('A { color: foobar(); }');
  # Object Oriented API w/ options
  my $sass = CSS::Sass->new(plugin_paths    => ['plugins'],
                            include_paths   => ['some/include/path'],
                            output_style    => SASS_STYLE_COMPRESSED,
                            source_map_file => 'output.css.map',
                            source_comments => 1,
                            dont_die        => 1,
                            sass_functions  => {
                              'foobar($arg)' => sub { $_[0] }
                            });
  # Compile string and use the registered function
  my ($css, $stats) = $sass->compile('A { color: foobar(red); }');
  # Result can be undef because 'dont_die' was set
  warn $sass->last_error unless (defined $css);
  # Functional API
  use CSS::Sass qw(:Default sass_compile);
  # Functional API, with error messages and source-map
  my ($css, $err, $stats) = sass_compile('A { color: red; }');
  die $err if defined $err;
  # Functional API, simple, with no error messages
  my $css = sass_compile('A { color: red; }');
  die unless defined $css;
  # Functional API w/ options
  my ($css, $err, $stats) = sass_compile('A { color: red; }',
                                         include_paths   => ['some/include/path'],
                                         output_style    => SASS_STYLE_NESTED,
                                         source_map_file => 'output.css.map');
  # Import sass2scss function
  use CSS::Sass qw(sass2scss);
  # convert indented syntax
  my $scss = sass2scss($sass);
  # Import quoting functions
  use CSS::Sass qw(quote unquote);
  # Exchange quoted strings
  my $string = unquote($from_sass);
  my $to_sass = quote($string, '"');

DESCRIPTION¶

CSS::Sass provides a perl interface to libsass, a fairly complete Sass compiler written in C++. It is currently around ruby sass 3.3/3.4 feature parity and heading towards full 3.4 compatibility. It can compile .scss and .sass files.

OBJECT ORIENTED INTERFACE¶

"new"

  $sass = CSS::Sass->new(options)
    

Creates a Sass object with the specified options. Example:

  $sass = CSS::Sass->new; # no options
  $sass = CSS::Sass->new(output_style => SASS_STYLE_NESTED);
    

compile(source_code)

  $css = $sass->compile("A { color: blue; }");
    

This compiles the Sass string that is passed in as the first parameter. It will croak() if there is an error, unless the "dont_die" option is set. It will return "undef" in that case.

"last_error"

  $sass->last_error
    

Returns the error encountered by the most recent invocation of "compile". This is only useful if the "dont_die" option is set.

"libsass" error messages are in the form ":$line:$column $error_message" so you can append them to the filename for a standard looking error message.

"options"

  $sass->options->{dont_die} = 1;
    

Allows you to inspect or change the options after a call to "new".

FUNCTIONAL INTERFACE¶

"$css = sass_compile(source_code, options)"

"($css, $err, $stats) = sass_compile(source_code, options)"

Compiles the sass code given by "source_code". It returns CSS, error and a status object in list context or just the CSS in scalar context. Either CSS or error will be "undef", but never both.

"$css = sass_compile_file(input_path, options)"

"($css, $err, $stats) = sass_compile_file(input_path, options)"

Compiles the sass file given by "input_path". It returns CSS, error and a status object in list context or just the CSS in scalar context. Either CSS or error will be "undef", but never both.

$stats status hash:

The status hash holds usefull information after compilation:

OPTIONS¶

"output_style"

"precision"

Set the floating point precision for output.

"linefeed"

Set the linefeed string used for css output.

"indent"

Set the indentation string used for css output.

"source_comments"

Set to "true" to get extra comments in the output, indicating what input line the code corresponds to.

"source_map_file"

Setting this option enables the source-map generating. The file will not actually be created, but its content will be returned to the caller. It will also enable sourceMappingURL comment by default. See "no_src_map_url".

"source_map_file_urls"

Render source entries in the source map json as file urls (`file:///`).

"source_map_root"

A path (string) that is directly embedded in the source map as "sourceRoot".

"source_map_embed"

Embeds the complete source-map content into the sourceMappingURL, by using base64 encoded data uri (sourceMappingURL=data:application/json;base64,XXXX)

"source_map_contents"

Embeds the content of each source inside a "sourcesContent" property in the source-map json. Setting this option along with "source_map_embed" allows for a completely self-contained source-map.

"no_src_map_url"

Set to "true" to omit the sourceMappingURL comment from the output css. Setting this options makes "source_map_embed" useless.

"include_paths"

This is an arrayref that holds the list a of paths to search (in addition to the current directory) when following Sass @import directives.

"plugin_paths"

This is an arrayref that holds a list of paths to search for third-party plugins. It will automatically load any <dll> or <so> library within that directory. This is currently a highly experimental libsass feature!

"dont_die"

This is only valid when used with the Object Oriented Interface. It is described in detail there.

"sass_functions"

This is a hash of Sass functions implemented in Perl. The key for each function should be the function's Sass signature and the value should be a Perl subroutine reference. This subroutine will be called whenever the function is used in the Sass being compiled. The arguments to the subroutine are CSS::Sass::Value objects, which map to native perl types if possible. You can return either CSS::Sass::Value objects or supported native perl data structures. "undef" is an equivalent of CSS::Sass::Value::Null->new.

The function is called with an "eval" statement so you may use "die" to throw errors back to libsass ("CSS::Sass::Value::Error").

A simple example:

    sass_functions => {
        'append_hello($str)' => sub {
            my ($str) = @_;
            die '$str should be a string' unless $str->isa("CSS::Sass::Value::String");
            return CSS::Sass::Value::String->new($str->value . " hello");
            # equivalent to return $str->value . " hello";
        }
    }
    

If this is encountered in the Sass:

    some_rule: append_hello("Well,");
    

Then the ouput would be:

    some_rule: Well, hello;
    

Custom "importer"

This is a function implemented in Perl that gets called for every @import statement. This feature is in an experimental stage and you have to be careful to return the expected structure. You can return multiple imports from one call to make it possible to implement globbing importers etc. If you omit $data, libsass will try to load the given path itself. It will go through the normal lockup algorithm as it would had encountered the "virtual" import statement on its own. $scope holds the current import path. Imports in css are meant to be relative to the parent scope, so you can use it to create absolute urls or paths within the context your working with.

A simple example:

    importer => sub {
      my ($import, $scope) = @_;
      return [
        # [ $real_path ] or [ $virtual_path, $data ],
        [ "http://xyz/file", "div { color: red; }" ],
      ];
    }
    

You may also return "undef" to skip the importer (usefull if an importer only handles certain url protocols). With the latest libsass version, you can add multiple importers with a priority order to implement more complex scenarios (highly experimental).

Custom "headers"

Another highly experimental feature to prepend content on every compilation. It can be used to predefine mixins or other stuff. Internally the content is really just added to the top of the processed data. Custom headers have the same structure as importers. But all registered headers are called in the order given by the priority flag.

"Sass_Value" Types

Sass knowns various "Sass_Value" types. We export the constants for completeness. Each type is mapped to a package inside the "CSS::Sass::Value" namespace.

    # Value types
    SASS_ERROR
    SASS_NULL
    SASS_BOOLEAN
    SASS_NUMBER
    SASS_STRING
    SASS_COLOR
    SASS_LIST
    SASS_MAP
    # List styles
    SASS_COMMA
    SASS_SPACE
    

Autodetection for value types returned by custom function

Many "Sass_Value" types can be mapped directly to perl data structures. "maps" and "lists" map directly to "hashes" and "arrays". Scalars are mapped to "string", "number" or "null". You can directly return these native data types from your custom functions or use the datastructures to access maps and lists.

    undef; # same as CSS::Sass::Value::Null->new;
    42; # same as CSS::Sass::Value::Number->new(42);
    "foobar"; # same as CSS::Sass::Value::String->new("foobar");
    [ 'foo', 'bar' ]; # same as CSS::Sass::Value::List->new('foo', 'bar');
    { key => 'value' }; # same as CSS::Sass::Value::Map->new(key => 'value');
    

We bless native return values from custom functions into the correct package.

    # sub get-map { return { key: "value" } };
    .class { content: map-get(get-map(), key); }
    # sub get-list { return [ 'foo', 42, 'bar' ] };
    .class { content: nth(get-list(), 2); }
    

MISCELLANEOUS¶

"SASS2SCSS_PRETTIFY_0"

Write everything on one line (minimized)

"SASS2SCSS_PRETTIFY_1"

Add lf after opening bracket (lisp style)

"SASS2SCSS_PRETTIFY_2"

Add lf after opening and before closing bracket (1TBS style)

"SASS2SCSS_PRETTIFY_3"

Add lf before/after opening and before closing (allman style)

"SASS2SCSS_KEEP_COMMENT"

Keep multi-line source code comments. Single-line comments are removed by default.

"SASS2SCSS_STRIP_COMMENT"

Strip all source code (single- and multi-line) comments.

"SASS2SCSS_CONVERT_COMMENT"

Convert single-line comments to mutli-line comments.

"sass2scss($sass, $options)"

We expose the "sass2scss" function, which can be used to convert indented sass syntax to the newer scss syntax. You may need this, since "libsass" will not automatically recognize the format of your string data.

    my $options = SASS2SCSS_PRETTIFY_1;
    $options |= SASS2SCSS_CONVERT_COMMENT;
    my $scss = sass2scss($sass, $options);
    

SEE ALSO¶

CSS::Sass::Value

The Sass Home Page <https://sass-lang.com/>

The libsass Home Page <https://github.com/sass/libsass>

The CSS::Sass Home Page <https://github.com/sass/perl-libsass>

AUTHOR¶

David Caldwell <david@porkrind.org> Marcel Greter <perl-libsass@ocbnet.ch>

LICENSE¶

The MIT License (MIT)

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.