Add utils.py

responsive/middleware.py

@@ -7,6 +7,7 @@
 from django.utils.encoding import force_text
 
 from .conf import settings
+from .utils import Device
 
 
 class ResponsiveMiddleware(object):
@@ -20,12 +21,20 @@ def process_request(self, request):
                 return
 
             try:
-                width, height, pixelratio = parts
-                width, height, pixelratio = int(width), int(height), float(pixelratio)
+                width, height, pixel_ratio = parts
+                width, height, pixel_ratio = int(width), int(height), float(pixel_ratio)
             except ValueError:
                 request.INVALID_RESPONSIVE_COOKIE = True
                 return
 
+            device_info = {
+                'width': width,
+                'height': height,
+                'pixel_ratio': pixel_ratio
+            }
+
+            request.device = Device(**device_info)
+
     def process_response(self, request, response):
         html_types = ('text/html', 'application/xhtml+xml')
         content_type = response.get('Content-Type', '').split(';')[0]

responsive/utils.py

@@ -0,0 +1,79 @@
+import six
+
+from django.core.cache import cache
+from django.core.exceptions import ImproperlyConfigured
+
+from .conf import settings
+
+
+class Device(object):
+
+    def __init__(self, width=0, height=0, pixel_ratio=1):
+        self.width = int(width)
+        self.height = int(height)
+        self.pixel_ratio = float(pixel_ratio)
+        self.matched = []
+
+        cache_key = '%(prefix)s%(width)s_%(height)s_%(pixel_ratio)s' % {
+            'prefix': settings.RESPONSIVE_CACHE_PREFIX,
+            'width': self.width,
+            'height': self.height,
+            'pixel_ratio': self.pixel_ratio
+        }
+        matches = cache.get(cache_key, None)
+        if not matches:
+            matches = self.match_media_queries()
+            cache.set(cache_key, matches, settings.RESPONSIVE_CACHE_DURATION)
+
+        for name, value in six.iteritems(matches):
+            setattr(self, 'is_%s' % name, value)
+            if value is True:
+                self.matched.append(name)
+
+    def match_media_queries(self):
+        matches = {}
+        media_queries = self.get_media_queries()
+        for alias, config in six.iteritems(media_queries):
+            yesno = []
+            if config['min_width']:
+                yesno.append(self.width >= config['min_width'])
+            if config['max_width']:
+                yesno.append(self.width <= config['max_width'])
+            if config['min_height']:
+                yesno.append(self.height >= config['min_height'])
+            if config['max_height']:
+                yesno.append(self.height <= config['max_height'])
+            if config['pixel_ratio']:
+                yesno.append(self.pixel_ratio == config['pixel_ratio'])
+
+            matches[alias] = all(yesno)
+        return matches
+
+    @staticmethod
+    def get_media_queries():
+        media_queries = settings.RESPONSIVE_MEDIA_QUERIES
+        for name, config in six.iteritems(media_queries):
+            for attr in ('min_width', 'max_width', 'min_height', 'max_height', 'pixel_ratio'):
+                if attr not in config:
+                    config[attr] = None
+                elif config[attr] is not None:
+                    try:
+                        config[attr] = int(config[attr]) if attr != 'pixel_ratio' \
+                            else float(config[attr])
+                    except ValueError:
+                        raise ImproperlyConfigured(
+                            'RESPONSIVE_MEDIA_QUERIES - %s for %s breakpoint must '
+                            'be a number.' % (attr, name))
+                else:
+                    media_queries[name][attr] = config[attr]
+        return media_queries
+
+    def clear(self):
+        cache.delete(self.cache_key)
+
+    def __str__(self):
+        return 'Device :: width=%(width)s height=%(height)s pixel-ratio=%(pixel_ratio)s' % {
+            'width': self.width,
+            'height': self.height,
+            'pixel_ratio': self.pixel_ratio
+        }