Implement IJSONSummarySerializerMetadata

news/1250.feature

@@ -0,0 +1,2 @@
+Implement IJSONSummarySerializerMetadata allowing addons to extend the metadata returned by Summary serializer.
+[ericof]

src/plone/restapi/interfaces.py

@@ -208,3 +208,19 @@ def __init__(field, context, request):
 
     def __call__(value):
         """Extract text from the block value. Returns text"""
+
+
+class IJSONSummarySerializerMetadata(Interface):
+    """Configure JSONSummary serializer."""
+
+    def default_metadata():
+        """Returns a set with default metadata to be serialized."""
+
+    def field_accessors():
+        """Returns a dictionary with field accessors to be used during serialization."""
+
+    def non_metadata_attributes():
+        """Returns a set with non metadata attributes."""
+
+    def blocklisted_attributes():
+        """Returns a set with attributes blocked during serialization."""

src/plone/restapi/serializer/configure.zcml

@@ -107,4 +107,10 @@
 
   <include package=".controlpanels" />
 
+  <!-- Summary Serializer Metadata -->
+  <utility
+      factory=".summary.JSONSummarySerializerMetadata"
+      name="plone.restapi.summary_serializer_metadata"
+      />
+
 </configure>

src/plone/restapi/serializer/summary.py

@@ -1,40 +1,66 @@
 from plone.app.contentlisting.interfaces import IContentListingObject
 from plone.restapi.interfaces import ISerializeToJsonSummary
+from plone.restapi.interfaces import IJSONSummarySerializerMetadata
 from plone.restapi.serializer.converters import json_compatible
 from Products.CMFCore.utils import getToolByName
 from Products.CMFCore.WorkflowCore import WorkflowException
 from Products.CMFPlone.interfaces import IPloneSiteRoot
 from zope.component import adapter
 from zope.interface import implementer
 from zope.interface import Interface
-
-# fmt: off
-DEFAULT_METADATA_FIELDS = {
-    '@id',
-    '@type',
-    'description',
-    'review_state',
-    'title',
-}
-
-FIELD_ACCESSORS = {
-    "@id": "getURL",
-    "@type": "PortalType",
-    "description": "Description",
-    "title": "Title",
-}
-
-NON_METADATA_ATTRIBUTES = {
-    "getPath",
-    "getURL",
-}
-
-BLACKLISTED_ATTRIBUTES = {
-    'getDataOrigin',
-    'getObject',
-    'getUserData',
-}
-# fmt: on
+from zope.component import getAllUtilitiesRegisteredFor
+
+
+@implementer(IJSONSummarySerializerMetadata)
+class JSONSummarySerializerMetadata:
+    def default_metadata_fields(self):
+        return {
+            "@id",
+            "@type",
+            "description",
+            "review_state",
+            "title",
+        }
+
+    def field_accessors(self):
+        return {
+            "@id": "getURL",
+            "@type": "PortalType",
+            "description": "Description",
+            "title": "Title",
+        }
+
+    def non_metadata_attributes(self):
+        return {
+            "getPath",
+            "getURL",
+        }
+
+    def blocklisted_attributes(self):
+        return {
+            "getDataOrigin",
+            "getObject",
+            "getUserData",
+        }
+
+
+def merge_serializer_metadata_utilities_data():
+    """Merge data returned by utilities registered for IJSONSummarySerializerMetadata."""
+    serializer_metadata = {
+        "default_metadata_fields": set(),
+        "field_accessors": {},
+        "non_metadata_attributes": set(),
+        "blocklisted_attributes": set(),
+    }
+    utils = getAllUtilitiesRegisteredFor(IJSONSummarySerializerMetadata)
+    for name in serializer_metadata.keys():
+        for util in utils:
+            method = getattr(util, name, None)
+            if not method:
+                continue
+            value = method()
+            serializer_metadata[name].update(value)
+    return serializer_metadata
 
 
 @implementer(ISerializeToJsonSummary)
@@ -49,15 +75,25 @@ class DefaultJSONSummarySerializer:
     def __init__(self, context, request):
         self.context = context
         self.request = request
+        # Cache summary_serializer_metadata on request
+        metadata = self.request.form.get("summary_serializer_metadata", None)
+        if not metadata:
+            metadata = merge_serializer_metadata_utilities_data()
+            self.request.set("summary_serializer_metadata", metadata)
+
+        self.default_metadata_fields = metadata["default_metadata_fields"]
+        self.field_accessors = metadata["field_accessors"]
+        self.non_metadata_attributes = metadata["non_metadata_attributes"]
+        self.blocklisted_attributes = metadata["blocklisted_attributes"]
 
     def __call__(self):
         obj = IContentListingObject(self.context)
 
         summary = {}
         for field in self.metadata_fields():
-            if field.startswith("_") or field in BLACKLISTED_ATTRIBUTES:
+            if field.startswith("_") or field in self.blocklisted_attributes:
                 continue
-            accessor = FIELD_ACCESSORS.get(field, field)
+            accessor = self.field_accessors.get(field, field)
             value = getattr(obj, accessor, None)
             try:
                 if callable(value):
@@ -78,11 +114,11 @@ def metadata_fields(self):
             fields_cache = self.request.get("_summary_fields_cache", None)
             if fields_cache is None:
                 catalog = getToolByName(self.context, "portal_catalog")
-                fields_cache = set(catalog.schema()) | NON_METADATA_ATTRIBUTES
+                fields_cache = set(catalog.schema()) | self.non_metadata_attributes
                 self.request.set("_summary_fields_cache", fields_cache)
             additional_metadata_fields = fields_cache
 
-        return DEFAULT_METADATA_FIELDS | additional_metadata_fields
+        return self.default_metadata_fields | additional_metadata_fields
 
 
 @implementer(ISerializeToJsonSummary)