pass additional arguments to as easy-thumbnail options, solves #38, m…

…ay solve #48

README.rst

@@ -88,9 +88,10 @@ area.
 Frontend
 ========
 
-django-image-cropping provides a templatetag for displaying a cropped thumbnail::
+django-image-cropping provides a templatetag for displaying a cropped thumbnail.
+Any other processor parameter (like ``bw=True`` or ``upscale=True``) will be forwarded to ``easy-thumbnails``::
 
-    {% cropped_thumbnail yourmodelinstance "ratiofieldname" [scale=INT|width=INT|height=INT|max_size="INTxINT"] [upscale=True] %}
+    {% cropped_thumbnail yourmodelinstance "ratiofieldname" [scale=INT|width=INT|height=INT|max_size="INTxINT"] %}
 
 Example usage::
 

example/tests/test_templatetag.py

@@ -1,12 +1,16 @@
 import itertools
+import urllib
 
+from PIL import Image
 from django.test import TestCase
+from django.conf import settings
 from django.template import Template, Context
 from django.core.management import call_command
 
 from .factory import create_cropped_image
 
 
+
 class TemplateTagTestBase(object):
     def setUp(self):
         # size of the example image is 400x400
@@ -105,6 +109,25 @@ def test_upscale(self):
     def test_adapt_rotation(self):
         pass
 
+    def test_parameter_forward(self):
+        ''' converts image to greyscale '''
+        def is_greyscale(img_path):
+            # http://stackoverflow.com/a/23661373
+            im = Image.open(img_path).convert('RGB')
+            w, h = im.size
+            for i in range(w):
+                for j in range(h):
+                    r, g, b = im.getpixel((i, j))
+                    if r != g != b:
+                        return False
+            return True
+
+        url = self._test_cropping({'max_size': '"200x200"',
+                                    'bw': True})
+        self.assertTrue('120x100' in url)
+        path = settings.MEDIA_ROOT.rsplit('/', 1)[0] + urllib.unquote(url)
+        self.assertTrue(is_greyscale(path))
+
 
 class FreeCroppingTestCase(TemplateTagTestBase, TestCase):
     def _test_free_cropping(self, options={}):

image_cropping/templatetags/cropping.py

@@ -2,6 +2,7 @@
 from easy_thumbnails.files import get_thumbnailer
 
 register = template.Library()
+VALID_OPTIONS = ('scale', 'width', 'height', 'max_size')
 
 
 @register.simple_tag(takes_context=True)
@@ -32,8 +33,7 @@ def cropped_thumbnail(context, instance, ratiofieldname, **kwargs):
     else:
         size = (int(ratiofield.width), int(ratiofield.height))
 
-    valid_options = ('scale', 'width', 'height', 'max_size')
-    if sum(k in kwargs for k in valid_options) > 1:
+    if sum(k in kwargs for k in VALID_OPTIONS) > 1:
         raise template.TemplateSyntaxError(
             'Only one size modifier is allowed.')
 
@@ -63,7 +63,7 @@ def cropped_thumbnail(context, instance, ratiofieldname, **kwargs):
             width = max_height * width / height
             height = max_height
 
-    if any(k in kwargs for k in valid_options):
+    if any(k in kwargs for k in VALID_OPTIONS):
         # adjust size based on given modifier
         size = (int(width), int(height))
 
@@ -77,7 +77,13 @@ def cropped_thumbnail(context, instance, ratiofieldname, **kwargs):
         'size': size,
         'box': box,
         'crop': True,
-        'detail': True,
+        'detail': kwargs.pop('detail', True),
         'upscale': kwargs.pop('upscale', False)
     }
+    # remove all cropping kwargs
+    for k in VALID_OPTIONS:
+        kwargs.pop(k, None)
+    # pass remaining arguments to easy_thumbnail
+    thumbnail_options.update(kwargs)
+
     return thumbnailer.get_thumbnail(thumbnail_options).url