Changeset 6290 for main/waeup.sirp

Timestamp:

6 Jun 2011, 22:47:53 (13 years ago)

Author:

uli

Message:

Set default for passport image via new
IContextAwareDefaultFactory. This bit is new in latest zope.schema and
enables definition of default values for interface fields, that should
be computed based on specific contexts. A side effect is, that the
default values for such fields are not set 'hardwired' during startup
but only, when a new object has to be created (after startup). So with
an IContextAwareDefaultFactory you can also use utilities and adapters
when defining a default value for some field.

The new zope.interface version we require enables the @provider
decorator we use when defining the new default passport image factory.

File:

• main/waeup.sirp/trunk/src/waeup/sirp/applicants/interfaces.py (modified) (3 diffs)

main/waeup.sirp/trunk/src/waeup/sirp/applicants/interfaces.py

@@ -28 +28 @@
 
 from zope import schema
-from zope.interface import Interface, Attribute
+from zope.interface import Interface, Attribute, provider
 from zope.component import getUtility, getUtilitiesFor
 from zope.pluggableauth.interfaces import IPrincipalInfo
@@ -56 +56 @@
     )
 
+@provider(schema.interfaces.IContextAwareDefaultFactory)
+def default_passport_image(context):
+    """A default value factory for ImageFile fields.
+
+    Returns some default image as WAeUPImageFile. We cannot set the
+    default directly in ImageFile fields, as, if we want to set
+    max_size or min_size as well, some utility lookups are needed
+    which are not possible during startup.
+
+    Developers which use IContextAwareDefaultFactories like this one
+    always should make sure that the delivered default meets all
+    constraints of the field that makes use of this default value
+    provider.
+    """
+    return DEFAULT_PASSPORT_IMAGE_MALE
+
 class ApplicantContainerProviderSource(BasicSourceFactory):
     """A source offering all available applicants container types.
@@ -332 +348 @@
     passport = ImageFile(
         title = u'Passport Photograph',
-        default = DEFAULT_PASSPORT_IMAGE_MALE,
+        #default = DEFAULT_PASSPORT_IMAGE_MALE,
+        defaultFactory = default_passport_image,
         required = True,
         max_size = 20480,