fix for cache-control headers

flask_iiif/restful.py

@@ -21,6 +21,7 @@
 from .decorators import api_decorator, error_handler
 from .signals import iiif_after_info_request, iiif_after_process_request, \
     iiif_before_info_request, iiif_before_process_request
+from .utils import should_cache
 
 current_iiif = LocalProxy(lambda: current_app.extensions['iiif'])
 
@@ -73,7 +74,8 @@ def get(self, version, uuid):
             data = current_iiif.uuid_to_image_opener(uuid)
             image = IIIFImageAPIWrapper.open_image(data)
             width, height = image.size()
-            cache_handler.set(key, "{0},{1}".format(width, height))
+            if should_cache(request.args):
+                cache_handler.set(key, "{0},{1}".format(width, height))
 
         data = current_app.config['IIIF_API_INFO_RESPONSE_SKELETON'][version]
 
@@ -166,7 +168,8 @@ def get(self, version, uuid, region, size, rotation, quality,
             # prepare image to be serve
             to_serve = image.serve(image_format=image_format)
             # to_serve = image.serve(image_format=image_format)
-            cache_handler.set(key, to_serve.getvalue())
+            if should_cache(request.args):
+                cache_handler.set(key, to_serve.getvalue())
 
         # decide the mime_type from the requested image_format
         mimetype = current_app.config['IIIF_FORMATS'].get(

flask_iiif/utils.py

@@ -141,3 +141,14 @@ def fill_background(image, demand_width, demand_height):
         offset_y = max(1, int((demand_height - h) / 2))
     background.paste(image, (offset_x, offset_y))
     return background
+
+
+def should_cache(request_args):
+    """Check the request args for cache-control specifications.
+
+    :param request_args: flask request args
+    """
+    if "cache-control" in request_args \
+            and request_args['cache-control'] in ["no-cache", "no-store"]:
+        return False
+    return True

tests/test_restful_api.py

@@ -280,3 +280,72 @@ def test_api_abort_all_methods_except_get(self):
             urlargs=data
         )
         self.assert405(get_the_response)
+
+    def test_api_cache_control(self):
+        """Test cache-control headers"""
+
+        urlargs = dict(
+            uuid=u'valid:id-üni',
+            version='v2',
+            region='200,200,200,200',
+            size='300,300',
+            rotation='!50',
+            quality='color',
+            image_format='pdf',
+        )
+
+        key = u'iiif:{0}/{1}/{2}/{3}/{4}.{5}'.format(
+            urlargs['uuid'],
+            urlargs['region'],
+            urlargs['size'],
+            urlargs['quality'],
+            urlargs['rotation'],
+            urlargs['image_format']
+        ).encode('utf8')
+
+        cache = self.app.config['IIIF_CACHE_HANDLER'].cache
+
+        get_the_response = self.get(
+            'iiifimageapi',
+            urlargs=urlargs,
+        )
+
+        self.assertFalse('cache-control' in urlargs)
+
+        self.assert200(get_the_response)
+
+        self.assertTrue(cache.get(key))
+
+        cache.clear()
+
+        for cache_control, name in (('no-cache', "foo.pdf"),
+                                    ('no-store', "foo.pdf")):
+
+            urlargs['cache-control'] = cache_control
+
+            get_the_response = self.get(
+                'iiifimageapi',
+                urlargs=urlargs,
+            )
+
+            self.assert200(get_the_response)
+
+            self.assertFalse(cache.get(key))
+
+            cache.clear()
+
+        for cache_control, name in (('public', "foo.pdf"),
+                                    ('no-transform', "foo.pdf")):
+
+            urlargs['cache-control'] = cache_control
+
+            get_the_response = self.get(
+                'iiifimageapi',
+                urlargs=urlargs,
+            )
+
+            self.assert200(get_the_response)
+
+            self.assertTrue(cache.get(key))
+
+            cache.clear()