Splitting seralizers into read and write ones

https://pulp.plan.io/issues/6775
closes #6775

CHANGES/6775.bugfix

@@ -0,0 +1 @@
+Fixed a bug that prevented write_only fields from being present in the API docs and bindings

pulpcore/app/openapigenerator.py

@@ -7,7 +7,7 @@
 from drf_yasg.generators import OpenAPISchemaGenerator
 from drf_yasg.inspectors import SwaggerAutoSchema
 from drf_yasg.openapi import Parameter
-from drf_yasg.utils import filter_none, force_real_str
+from drf_yasg.utils import filter_none, force_real_str, get_serializer_ref_name, no_body
 from rest_framework import serializers
 
 from pulpcore.app.models import Export, Import, RepositoryVersion
@@ -459,18 +459,48 @@ def get_tags(self, operation_keys):
 
         return tags
 
-    def serializer_to_schema(self, serializer):
+    def get_default_response_serializer(self):
         """
-        Convert a serializer to an OpenAPI Schema.
-        Patch: https://github.com/axnsan12/drf-yasg/issues/70#issuecomment-485050813
+        Return the default response serializer for this endpoint.
+
+        Reference: https://github.com/axnsan12/drf-yasg/issues/70#issuecomment-485050813
         """
+        body_override = self._get_request_body_override()
+        if body_override and body_override is not no_body:
+            return body_override
+
+        return self._convert_serializer_to_read_only()
 
-        if self.method.lower() == "get":
-            new_fields = OrderedDict()
-            for field_name, field in serializer.fields.items():
-                if not field.write_only:  # Removing write_only fields
-                    new_fields[field_name] = field
+    def _convert_serializer_to_read_only(self):
+        """
+        Convert a serializer into Read only serializer.
 
-            serializer.fields = new_fields
+        Reference: https://github.com/axnsan12/drf-yasg/issues/70#issuecomment-485050813
+        """
+        original_serializer = super().get_view_serializer()
+        if not original_serializer:
+            return
+        serializer_meta = getattr(original_serializer, "Meta", BlankMeta)
+        read_ref_name = f"{get_serializer_ref_name(original_serializer)}Read"
+        read_fields = OrderedDict()
+        for field_name, field in original_serializer.fields.items():
+            if not field.write_only:
+                read_fields[field_name] = field
+
+        class ReadOnlySerializer(original_serializer.__class__):
+            class Meta(serializer_meta):
+                ref_name = read_ref_name
+
+        read_serializer = ReadOnlySerializer(data=original_serializer.data)
+        read_serializer.fields = read_fields
+        return read_serializer
+
+
+class BlankMeta:
+    """
+    Creates a blank Meta for serializers
+
+    Reference: https://github.com/axnsan12/drf-yasg/issues/70#issuecomment-485050813
+    """
 
-        return super().serializer_to_schema(serializer)
+    pass