Factor out imaging related helper functions.

src/plone/restapi/imaging.py

@@ -0,0 +1,45 @@
+# -*- coding: utf-8 -*-
+from Products.CMFCore.interfaces import IPropertiesTool
+from zope.component import getUtility
+
+try:
+    from Products.CMFPlone.factory import _IMREALLYPLONE5  # noqa
+except ImportError:
+    PLONE_5 = False  # pragma: no cover
+else:
+    PLONE_5 = True  # pragma: no cover
+
+
+def get_scales(context):
+    absolute_url = context.absolute_url()
+    scales = {name: {
+        u'download': u'{0}/@@images/image/{1}'.format(absolute_url, name),
+        u'width': width,
+        u'height': height}
+        for name, width, height in get_scale_infos()}
+
+    return scales
+
+
+def get_scale_infos():
+    if PLONE_5:
+        from plone.registry.interfaces import IRegistry
+        registry = getUtility(IRegistry)
+        from Products.CMFPlone.interfaces import IImagingSchema
+        imaging_settings = registry.forInterface(
+            IImagingSchema,
+            prefix='plone'
+        )
+        allowed_sizes = imaging_settings.allowed_sizes
+
+    else:
+        ptool = getUtility(IPropertiesTool)
+        image_properties = ptool.imaging_properties
+        allowed_sizes = image_properties.getProperty('allowed_sizes')
+
+    def split_scale_info(allowed_size):
+        name, dims = allowed_size.split(' ')
+        width, height = map(int, dims.split(':'))
+        return name, width, height
+
+    return [split_scale_info(size) for size in allowed_sizes]

src/plone/restapi/serializer/atfields.py

@@ -5,13 +5,12 @@
 from Products.Archetypes.interfaces.field import IImageField
 from Products.Archetypes.interfaces.field import IReferenceField
 from Products.Archetypes.interfaces.field import ITextField
-from Products.CMFCore.interfaces import IPropertiesTool
 from plone.app.blob.interfaces import IBlobField
 from plone.app.blob.interfaces import IBlobImageField
 from plone.restapi.interfaces import IFieldSerializer
+from plone.restapi.imaging import get_scales
 from plone.restapi.serializer.converters import json_compatible
 from zope.component import adapter
-from zope.component import getUtility
 from zope.interface import Interface
 from zope.interface import implementer
 
@@ -80,7 +79,7 @@ def __call__(self):
 
         download_url = '/'.join((
             self.context.absolute_url(), '@@images', self.field.__name__))
-        scales = self.get_scales()
+        scales = get_scales(self.context)
         result = {
             'filename': self.field.getFilename(self.context),
             'content-type': self.field.getContentType(self.context),
@@ -90,39 +89,6 @@ def __call__(self):
         }
         return json_compatible(result)
 
-    def get_scales(self):
-        absolute_url = self.context.absolute_url()
-        scales = {name: {
-            u'download': u'{0}/@@images/image/{1}'.format(absolute_url, name),
-            u'width': width,
-            u'height': height}
-            for name, width, height in self.get_scale_infos()}
-
-        return scales
-
-    def get_scale_infos(self):
-        if PLONE_5:
-            from plone.registry.interfaces import IRegistry
-            registry = getUtility(IRegistry)
-            from Products.CMFPlone.interfaces import IImagingSchema
-            imaging_settings = registry.forInterface(
-                IImagingSchema,
-                prefix='plone'
-            )
-            allowed_sizes = imaging_settings.allowed_sizes
-
-        else:
-            ptool = getUtility(IPropertiesTool)
-            image_properties = ptool.imaging_properties
-            allowed_sizes = image_properties.getProperty('allowed_sizes')
-
-        def split_scale_info(allowed_size):
-            name, dims = allowed_size.split(' ')
-            width, height = map(int, dims.split(':'))
-            return name, width, height
-
-        return [split_scale_info(size) for size in allowed_sizes]
-
 
 @adapter(IBlobField, IBaseObject, Interface)
 @implementer(IFieldSerializer)

src/plone/restapi/serializer/dxfields.py

@@ -2,24 +2,15 @@
 from plone.dexterity.interfaces import IDexterityContent
 from plone.namedfile.interfaces import INamedFileField
 from plone.namedfile.interfaces import INamedImageField
+from plone.restapi.imaging import get_scales
 from plone.restapi.interfaces import IFieldSerializer
 from plone.restapi.serializer.converters import json_compatible
-from Products.CMFCore.interfaces import IPropertiesTool
 from zope.component import adapter
-from zope.component import getUtility
 from zope.interface import implementer
 from zope.interface import Interface
 from zope.schema.interfaces import IField
 
 
-try:
-    from Products.CMFPlone.factory import _IMREALLYPLONE5  # noqa
-except ImportError:
-    PLONE_5 = False  # pragma: no cover
-else:
-    PLONE_5 = True  # pragma: no cover
-
-
 @adapter(IField, IDexterityContent, Interface)
 @implementer(IFieldSerializer)
 class DefaultFieldSerializer(object):
@@ -48,7 +39,7 @@ def __call__(self):
 
         download_url = '/'.join((
             self.context.absolute_url(), '@@images', self.field.__name__))
-        scales = self.get_scales()
+        scales = get_scales(self.context)
         result = {
             'filename': namedimage.filename,
             'content-type': namedimage.contentType,
@@ -58,39 +49,6 @@ def __call__(self):
         }
         return json_compatible(result)
 
-    def get_scales(self):
-        absolute_url = self.context.absolute_url()
-        scales = {name: {
-            u'download': u'{0}/@@images/image/{1}'.format(absolute_url, name),
-            u'width': width,
-            u'height': height}
-            for name, width, height in self.get_scale_infos()}
-
-        return scales
-
-    def get_scale_infos(self):
-        if PLONE_5:
-            from plone.registry.interfaces import IRegistry
-            registry = getUtility(IRegistry)
-            from Products.CMFPlone.interfaces import IImagingSchema
-            imaging_settings = registry.forInterface(
-                IImagingSchema,
-                prefix='plone'
-            )
-            allowed_sizes = imaging_settings.allowed_sizes
-
-        else:
-            ptool = getUtility(IPropertiesTool)
-            image_properties = ptool.imaging_properties
-            allowed_sizes = image_properties.getProperty('allowed_sizes')
-
-        def split_scale_info(allowed_size):
-            name, dims = allowed_size.split(' ')
-            width, height = map(int, dims.split(':'))
-            return name, width, height
-
-        return [split_scale_info(size) for size in allowed_sizes]
-
 
 @adapter(INamedFileField, IDexterityContent, Interface)
 class FileFieldSerializer(DefaultFieldSerializer):