Added jinja2 extension

compressor/contrib/jinja2ext.py

@@ -0,0 +1,78 @@
+from jinja2 import nodes
+from jinja2.ext import Extension
+from jinja2.exceptions import TemplateSyntaxError
+from django.core.exceptions import ImproperlyConfigured
+from compressor.conf import settings
+from compressor.utils import get_class
+from compressor.templatetags.compress import COMPRESSORS, OUTPUT_FILE
+from compressor.cache import (cache_get, cache_set,
+                              get_templatetag_cachekey)
+
+
+class CompressorExtension(Extension):
+
+    tags = set(['compress'])
+
+    def parse(self, parser):
+        lineno = parser.stream.next().lineno
+        kindarg = parser.parse_expression()
+        # Allow kind to be defined as jinja2 name node
+        if isinstance(kindarg, nodes.Name):
+            kindarg = nodes.Const(kindarg.name)
+        args = [kindarg]
+        if args[0].value not in COMPRESSORS:
+            raise TemplateSyntaxError('compress kind may be "css" or "js"',
+                lineno)
+        if parser.stream.skip_if('comma'):
+            modearg = parser.parse_expression()
+            # Allow mode to be defined as jinja2 name node
+            if isinstance(modearg, nodes.Name):
+                modearg = nodes.Const(modearg.name)
+                args.append(modearg)
+        else:
+            args.append(nodes.Const('file'))
+        body = parser.parse_statements(['name:endcompress'], drop_needle=True)
+        return nodes.CallBlock(self.call_method('_compress', args), [], [],
+            body).set_lineno(lineno)
+
+    def _compress(self, kind, mode, caller):
+        mode = mode or OUTPUT_FILE
+        Compressor = get_class(COMPRESSORS.get(kind),
+            exception=ImproperlyConfigured)
+        original_content = caller()
+        compressor = Compressor(original_content)
+        # This extension assumes that we won't force compression
+        forced = False
+
+        # Prepare the actual compressor and check cache
+        cache_key, cache_content = self.render_cached(kind, mode, compressor,
+            forced)
+        if cache_content is not None:
+            return cache_content
+
+        # call compressor output method and handle exceptions
+        try:
+            rendered_output = compressor.output(mode, forced)
+            if cache_key:
+                cache_set(cache_key, rendered_output)
+            return rendered_output
+        except Exception, e:
+            if settings.DEBUG:
+                raise e
+
+        # Or don't do anything in production
+        return original_content
+
+    def render_cached(self, kind, mode, compressor, forced):
+        """
+        If enabled checks the cache for the given compressor's cache key
+        and return a tuple of cache key and output
+        """
+        if settings.COMPRESS_ENABLED and not forced:
+            cache_key = get_templatetag_cachekey(
+                compressor, mode, kind)
+            cache_content = cache_get(cache_key)
+            return cache_key, cache_content
+        return None, None
+
+