Dataloading person's current roles

alphagov · Dec 19, 2024 · 5ec7515 · 5ec7515
1 parent 96561ff
commit 5ec7515
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Showing 2 changed files with 44 additions and 23 deletions.
diff --git a/app/graphql/sources/person_current_roles_source.rb b/app/graphql/sources/person_current_roles_source.rb
@@ -0,0 +1,42 @@
+module Sources
+  class PersonCurrentRolesSource < GraphQL::Dataloader::Source
+    def fetch(person_content_ids)
+      all_roles = Edition
+        .live
+        .includes(
+          document: {
+            reverse_links: { # role -> role_appointment
+              link_set: {
+                documents: [
+                  :editions, # role_appointment
+                  :link_set_links, # role_appointment -> person
+                ],
+              },
+            },
+          },
+        )
+        .where(
+          document_type: "ministerial_role",
+          document: { locale: "en" },
+          reverse_links: { link_type: "role" },
+          editions_documents: { document_type: "role_appointment" },
+          link_set_links: { target_content_id: person_content_ids, link_type: "person" },
+        )
+        .where("editions_documents.details ->> 'current' = 'true'") # editions_documents is the alias that Active Record gives to the role_appointment Editions in the SQL query
+        .order(reverse_links: { position: :asc })
+
+      ids_map = person_content_ids.index_with { [] }
+
+      all_roles.each_with_object(ids_map) { |role, hash|
+        person_content_id = role.document.reverse_links
+          .select { |link| link.link_type == "role" } # role -> role_appointment
+          .flat_map { |link| link.link_set.documents }
+          .flat_map(&:link_set_links)
+          .select { |link| link.link_type == "person" } # role_appointment -> person
+          .map(&:target_content_id).first
+
+        hash[person_content_id] << role
+      }.values
+    end
+  end
+end
diff --git a/app/graphql/types/ministers_index_type.rb b/app/graphql/types/ministers_index_type.rb
@@ -59,29 +59,8 @@ class MinistersIndexPersonLinks < Types::BaseObject
         field :role_appointments, [MinistersIndexRoleAppointment]
 
         def role_appointments
-          Edition
-            .live
-            .includes(
-              document: {
-                reverse_links: { # role -> role_appointment
-                  link_set: {
-                    documents: [
-                      :editions, # role_appointment
-                      :link_set_links, # role_appointment -> person
-                    ],
-                  },
-                },
-              },
-            )
-            .where(
-              document_type: "ministerial_role",
-              document: { locale: "en" },
-              reverse_links: { link_type: "role" },
-              editions_documents: { document_type: "role_appointment" },
-              link_set_links: { target_content_id: object.content_id, link_type: "person" },
-            )
-            .where("editions_documents.details ->> 'current' = 'true'") # editions_documents is the alias that Active Record gives to the role_appointment Editions in the SQL query
-            .order(reverse_links: { position: :asc })
+          dataloader.with(Sources::PersonCurrentRolesSource)
+            .load(object.content_id)
         end
       end