Merge pull request #129 from plone/maurits-custom-title

Get title from ImageScale class.

news/128.bugfix

@@ -0,0 +1,4 @@
+Get title from ImageScale class.
+Prevents a traceback when the context is a tile.
+When no title can we found, fall back to an empty string.
+[maurits]

plone/namedfile/scaling.py

@@ -107,6 +107,24 @@ def srcset_attribute(self):
         srcset_attr = ", ".join(_srcset_attr)
         return srcset_attr
 
+    @property
+    def title(self):
+        """Get the title from the context.
+
+        Let's not fail when we cannot find a title.
+        """
+        try:
+            # Most Plone content items.
+            return self.context.Title()
+        except AttributeError:
+            pass
+        try:
+            # Can work on a tile and most other things.
+            return self.context.title
+        except AttributeError:
+            pass
+        return ""
+
     def tag(
         self,
         height=_marker,
@@ -123,9 +141,9 @@ def tag(
             width = getattr(self, "width", self.data._width)
 
         if alt is _marker:
-            alt = self.context.Title()
+            alt = self.title
         if title is _marker:
-            title = self.context.Title()
+            title = self.title
 
         values = [
             ("src", self.url),

plone/namedfile/tests/test_scaling.py

@@ -6,6 +6,7 @@
 from plone.namedfile.file import NamedImage
 from plone.namedfile.interfaces import IAvailableSizes
 from plone.namedfile.interfaces import IImageScaleTraversable
+from plone.namedfile.scaling import ImageScale
 from plone.namedfile.scaling import ImageScaling
 from plone.namedfile.testing import PLONE_NAMEDFILE_FUNCTIONAL_TESTING
 from plone.namedfile.testing import PLONE_NAMEDFILE_INTEGRATION_TESTING
@@ -296,6 +297,13 @@ def get_info_by_hash(self, hash):
                 return value
 
 
+class TitleImageScale(ImageScale):
+    """ImageScale class with its own title property.
+    """
+
+    title = "title from class"
+
+
 # @patch.multiple(
 #     "plone.namedfile.scaling.Img2PictureTag",
 #     allowed_scales=patch_Img2PictureTag_allowed_scales,
@@ -926,6 +934,28 @@ def test_height(self):
         self.assertEqual(scale_uid.data.info["uid"], "uid-0")
         self.assertIs(scale_uid.data, scale2.data)
 
+    def test_title(self):
+        # Test that a custom title property on an ImageScale class is used.
+        item = FakeImage("abcdef", "jpeg")
+        scaling = ImageScaling(item, None)
+        scaling._scale_view_class = TitleImageScale
+        self.assertEqual(
+            scaling.tag("image"),
+            '<img src="http://fake.image/@@images/image.jpeg" alt="title from class" title="title from class" height="4" width="6" />'
+        )
+        self.assertEqual(
+            scaling.tag("image", alt="own alt"),
+            '<img src="http://fake.image/@@images/image.jpeg" alt="own alt" title="title from class" height="4" width="6" />'
+        )
+        self.assertEqual(
+            scaling.tag("image", title="own title"),
+            '<img src="http://fake.image/@@images/image.jpeg" alt="title from class" title="own title" height="4" width="6" />'
+        )
+        self.assertEqual(
+            scaling.tag("image", alt="own alt", title="own title"),
+            '<img src="http://fake.image/@@images/image.jpeg" alt="own alt" title="own title" height="4" width="6" />'
+        )
+
 
 def test_suite():
     from unittest import defaultTestLoader