Added event template, updated docs

src/main/proto/wfa/measurement/reporting/v2alpha/basic_report.proto

@@ -42,6 +42,7 @@ message BasicReport {
   // Human readable title of the report.
   string title = 2 [(google.api.field_behavior) = IMMUTABLE];
 
+  // A campaign group is the subject of the report.
   message CampaignGroup {
     // This is the resource name of a primitive ReportingSet that includes all
     // of the EventGroups that may be reported on.
@@ -54,6 +55,8 @@ message BasicReport {
       (google.api.field_behavior) = IMMUTABLE
     ];
 
+    // Human readable name for the campaign group. This is the ReportingSet's
+    // display_name.
     string display_name = 2 [
       (google.api.field_behavior) = IMMUTABLE,
       (google.api.field_behavior) = OUTPUT_ONLY
@@ -82,8 +85,8 @@ message BasicReport {
 
   // The report results
   repeated Page pages = 6 [
-    (google.api.field_behavior) = OUTPUT_ONLY,
-    (google.api.field_behavior) = IMMUTABLE
+    (google.api.field_behavior) = IMMUTABLE,
+    (google.api.field_behavior) = OUTPUT_ONLY
   ];
 
   // The time when the BasicReport was created.

src/main/proto/wfa/measurement/reporting/v2alpha/event_template_field.proto

@@ -0,0 +1,55 @@
+// Copyright 2025 The Cross-Media Measurement Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//      http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+syntax = "proto3";
+
+package wfa.measurement.reporting.v2alpha;
+
+import "google/api/field_behavior.proto";
+
+option java_package = "org.wfanet.measurement.reporting.v2alpha";
+option java_multiple_files = true;
+option java_outer_classname = "EventTemplateFieldProto";
+
+// A representation of an event template field with its value
+message EventTemplateField {
+  // A field path with respect to the local market Event message
+  // with `.` as the traversal operator.
+  //
+  // For example, if the Event message had an event template `common` with
+  // a field `age_group` then the field path would be `common.age_group`.
+  string path = 1 [
+    (google.api.field_behavior) = REQUIRED,
+    (google.api.field_behavior) = IMMUTABLE
+  ];
+  // The value of the event template field
+  message FieldValue {
+    // Value type selector. Required.
+    oneof selector {
+      // The field value as a string
+      string string_value = 1 [(google.api.field_behavior) = IMMUTABLE];
+      // The field value as a stringified enum value. This is the symbol
+      // associated with the enum value, not a stringification of its integer
+      // value. For example, for MediaType.VIDEO we expect "VIDEO" not "1"
+      string enum_value = 2 [(google.api.field_behavior) = IMMUTABLE];
+      // The field value as a Boolean
+      bool bool_value = 3 [(google.api.field_behavior) = IMMUTABLE];
+    }
+  }
+  // The value of the field
+  FieldValue value = 2 [
+    (google.api.field_behavior) = REQUIRED,
+    (google.api.field_behavior) = IMMUTABLE
+  ];
+}