Merge pull request #18 from plone/issue_16_1x

Issue 16 1.0.x - Fix incompatibilities with five.pt and chameleon

docs/HISTORY.txt

@@ -6,6 +6,9 @@ Changelog
 
 Fixes:
 
+- Fixed incompatibilities with five.pt and chameleon (closes `#16`_).
+  [rodfersou, maurits]
+
 - Fixed 404 NotFound error when accessing image scales via webdav.
   [maurits]
 
@@ -239,3 +242,5 @@ Fixes:
 
 - Initial package structure.
   [zopeskel]
+
+.. _`#16`: https://github.com/plone/plone.app.imaging/issues/16

src/plone/app/imaging/scaling.py

@@ -79,13 +79,54 @@ def publishTraverse(self, request, name):
         raise NotFound(self, name, self.request)
 
     def traverse(self, name, furtherPath):
-        """ used for path traversal, i.e. in zope page templates """
+        """Used for path traversal, i.e. in zope page templates.
+
+        This method is called when you have something like this in a
+        page template:
+
+        <img tal:replace="structure context/@@images/image/mini" />
+
+        What then happens during traversal, is that the traverse method
+        gets called twice: we first traverse to name='image' and then to
+        name='mini'.  The traversal is done by the Zope page template
+        machinery.  There are differences between standard
+        zope.pagetemplate and five.pt (chameleon).  Roughly, it happens
+        like follows.
+
+        With zope.pagetemplate:
+
+        view = <the @@images view for this context>
+        new_view = view.traverse('image', ['mini'])
+        tag = new_view.traverse('mini', [])
+
+        And with five.pt:
+
+        view = <the @@images view for this context>
+        new_view = view.traverse('image', ('mini', ))
+        tag = new_view.traverse('mini', ())
+        """
         if not furtherPath:
+            if hasattr(self, '_image_fieldname'):
+                # We have been here before, with the current name argument in
+                # the furtherPath.
+                scale_name = name
+                name = self._image_fieldname
+            else:
+                scale_name = None
             field = self.context.getField(name)
-            return field.get(self.context).tag()
-        image = self.scale(name, furtherPath.pop())
-        if image is not None:
-            return image.tag()
+            image = self.scale(name, scale_name)
+            if image is not None:
+                return image.tag()
+            raise TraversalError(self, name)
+        field = self.field(name)
+        if field is not None:
+            # We have an image field of this name.  Store the scale name on
+            # self and return it.  Since there is a furtherPath, we will get
+            # called again in a moment, with this same 'self' with the
+            # _image_fieldname attribute, and with the current furtherPath as
+            # name, and an empty furtherPath.
+            self._image_fieldname = name
+            return self
         raise TraversalError(self, name)
 
     def make(self, info):

src/plone/app/imaging/tests/test_new_scaling.py

@@ -5,7 +5,19 @@
 from unittest import TestSuite, makeSuite
 
 
-class ImageTraverseTests(ImagingTestCase):
+class ImageStandardTraverseTests(ImagingTestCase):
+    # Note: this class is subclassed by ImageChameleonTraverseTests, which
+    # inherits our tests but uses a different traverser.  We use the standard
+    # Zope pagetemplate traverser.
+
+    def traverser(self, view, path=''):
+        # Standard Zope page template traversal uses a list as path.
+        # This is a simplified version specialised for the scaling view.
+        stack = path.split('/')
+        while stack:
+            name = stack.pop(0)
+            view = view.traverse(name, stack)
+        return view
 
     def afterSetUp(self):
         self.data = self.getImage()
@@ -16,9 +28,7 @@ def afterSetUp(self):
 
     def traverse(self, path=''):
         view = self.image.unrestrictedTraverse('@@images')
-        stack = path.split('/')
-        name = stack.pop(0)
-        tag = view.traverse(name, stack)
+        tag = self.traverser(view, path)
         base = self.image.absolute_url()
         expected = r'<img src="%s/@@images/([-0-9a-f]{36}).(jpeg|gif|png)" ' \
             r'alt="foo" title="foo" height="(\d+)" width="(\d+)" />' % base
@@ -69,6 +79,35 @@ def testCustomSizeChange(self):
         self.assertEqual(height, 42)
         self.assertNotEqual(uid1, uid2, 'scale not updated?')
 
+
+class ImageChameleonTraverseTests(ImageStandardTraverseTests):
+    # This class inherits all test methods from its parent, but uses the
+    # Chameleon/five.pt traverser.
+
+    def traverser(self, view, path=''):
+        # five.pt/chameleon uses a tuple as path.  This is a simplified
+        # version of BoboAwareZopeTraverse.traverse from five.pt.expressions,
+        # specialised for the scaling view.
+        path_items = tuple(path.split('/'))
+        length = len(path_items)
+        if length:
+            i = 0
+            while i < length:
+                name = path_items[i]
+                i += 1
+                view = view.traverse(name, path_items[i:])
+        return view
+
+
+class ImageTagTests(ImagingTestCase):
+
+    def afterSetUp(self):
+        self.data = self.getImage()
+        self.image = self.folder[self.folder.invokeFactory(
+            'Image', id='foo', image=self.data)]
+        field = self.image.getField('image')
+        self.available = field.getAvailableSizes(self.image)
+
     def testViewTagMethod(self):
         folder = self.folder
         image = folder['foo']
@@ -315,7 +354,9 @@ def testGetImageSize(self):
 
 def test_suite():
     return TestSuite([
-        makeSuite(ImageTraverseTests),
+        makeSuite(ImageStandardTraverseTests),
+        makeSuite(ImageChameleonTraverseTests),
+        makeSuite(ImageTagTests),
         makeSuite(ImagePublisherTests),
         makeSuite(ScalesAdapterTests),
     ])