"Merge pull request #352 from sirex/libsass\n\nLibsass filter, fixes #…

…145"

Conflicts:
	requirements-dev.pip

requirements-dev.pip

@@ -22,6 +22,7 @@ cssutils
 yuicompressor
 closure
 slimit
+libsass
 
 # Python libs that requiring manual installation
 #cssprefixer

src/webassets/filter/libsass.py

@@ -0,0 +1,77 @@
+# coding: utf-8
+
+"""
+This filter based on Jesús Jerez <jerezmoreno@gmail.com> code [1].
+
+[1] https://bitbucket.org/jhuss/webassets-libsass
+"""
+
+from __future__ import print_function
+from __future__ import absolute_import
+
+from webassets.filter import Filter
+
+
+__all__ = ('LibSass',)
+
+
+class LibSass(Filter):
+    """Converts `Sass <http://sass-lang.com/>`_ markup to real CSS.
+
+    Requires the ``libsass`` package (https://pypi.python.org/pypi/libsass)::
+
+        pip install libsass
+
+    `libsass <http://dahlia.kr/libsass-python>`_ is binding to C/C++
+    implementation of a Sass compiler `Libsass
+    <https://github.com/hcatlin/libsass>`_
+
+    *Configuration options:*
+
+    LIBSASS_STYLE (style)
+        an optional coding style of the compiled result. choose one of:
+        `nested` (default), `expanded`, `compact`, `compressed`
+
+    LIBSASS_INCLUDES (includes)
+        an optional list of paths to find @imported SASS/CSS source files
+
+    LIBSASS_IMAGES (images)
+        an optional path to find images
+
+    See libsass documentation for full documentation about these configuration
+    options:
+
+        http://hongminhee.org/libsass-python/sass.html#sass.compile
+    """
+    name = 'libsass'
+    options = {
+        'style': 'LIBSASS_STYLE',
+        'includes': 'LIBSASS_INCLUDES',
+        'images': 'LIBSASS_IMAGES',
+    }
+
+    def setup(self):
+        super(LibSass, self).setup()
+
+        try:
+            import sass
+        except ImportError:
+            raise EnvironmentError('The "libsass" package is not installed.')
+        else:
+            self.sass = sass
+
+        if not self.style:
+            self.style = 'nested'
+
+    def input(self, _in, out, **kwargs):
+        source_path = kwargs['source_path']
+
+        out.write(
+            # http://hongminhee.org/libsass-python/sass.html#sass.compile
+            self.sass.compile(
+                filename=source_path,
+                output_style=self.style,
+                include_paths=(self.includes if self.includes else []),
+                image_path=(self.images if self.images else '')
+            )
+        )

tests/test_filters.py

@@ -994,6 +994,32 @@ def test_assets(self):
             self.get('out.css'),)
 
 
+class TestLibSass(TempEnvironmentHelper):
+    default_files = {
+        'foo.scss': '@import "bar"; a {color: red + green; }',
+        'bar.scss': 'h1{color:red}'
+    }
+
+    def setup(self):
+        try:
+            import sass
+            self.sass = sass
+        except ImportError:
+            raise SkipTest()
+        TempEnvironmentHelper.setup(self)
+
+    def test(self):
+        self.mkbundle('foo.scss', filters='libsass', output='out.css').build()
+        assert self.get('out.css') == (
+            'h1 {\n  color: red; }\n\na {\n  color: #ff8000; }\n'
+        )
+
+    def test_compressed(self):
+        libsass = get_filter('libsass', style='compressed')
+        self.mkbundle('foo.scss', filters=libsass, output='out.css').build()
+        assert self.get('out.css') == 'h1{color:red;}a{color:#ff8000;}'
+
+
 class TestCompass(TempEnvironmentHelper):
 
     default_files = {