Don't attempt to compress CSS or JS if the compressor class is empty.

The CSS and JS compressors can be turned off individually by specifying
either None or an empty string as the value for either
PIPELINE_CSS_COMPRESSOR or PIPELINE_JS_COMPRESSOR.

This is useful when you want to conditionally disable a compressor based
on what's available locally, or when a byproduct of a compiler is to
compress the content.

Signed-off-by: Timothée Peignier <timothee.peignier@tryphon.org>

docs/configuration.rst

@@ -174,6 +174,8 @@ Other settings
 ............................
 
   Compressor class to be applied to CSS files.
+
+  If empty or ``None``, CSS files won't be compressed.
   
   Defaults to ``'pipeline.compressors.yui.YUICompressor'``.
 
@@ -181,6 +183,8 @@ Other settings
 ...........................
 
   Compressor class to be applied to JavaScript files.
+
+  If empty or ``None``, JavaScript files won't be compressed.
   
   Defaults to ``'pipeline.compressors.yui.YUICompressor'``
 

pipeline/compressors/__init__.py

@@ -52,13 +52,20 @@ class Compressor(object):
         if templates:
             js = js + self.compile_templates(templates)
         js = "(function() { %s }).call(this);" % js
-        js = getattr(self.js_compressor(verbose=self.verbose), 'compress_js')(js)
+
+        compressor = self.js_compressor
+        if compressor:
+            js = getattr(compressor(verbose=self.verbose), 'compress_js')(js)
+
         return js
 
     def compress_css(self, paths, variant=None, asset_url=None, **kwargs):
         """Concatenate and compress CSS files"""
         css = self.concatenate_and_rewrite(paths, variant)
-        css = getattr(self.css_compressor(verbose=self.verbose), 'compress_css')(css)
+
+        compressor = self.css_compressor
+        if compressor:
+            css = getattr(compressor(verbose=self.verbose), 'compress_css')(css)
         if not variant:
             return css
         elif variant == "datauri":

pipeline/utils.py

@@ -5,6 +5,9 @@ from django.utils import importlib
 
 
 def to_class(class_str):
+    if not class_str:
+        return None
+
     module_bits = class_str.split('.')
     module_path, class_name = '.'.join(module_bits[:-1]), module_bits[-1]
     module = importlib.import_module(module_path)