Java bindings ValueDecoder allows decoding values with extra fields #27406 - fromCreatedEvent for Contract classes

sdk/UNRELEASED.md

@@ -9,6 +9,9 @@ schedule, i.e. if you add an entry effective at or after the first
 header, prepend the new date header that corresponds to the
 Wednesday after your change.
 
+## Until 2026-03-31 (Exclusive)
+- Codegen-java: Added support for `UnknownTrailingFieldPolicy` in the generated `fromCreatedEvent()` method.
+
 ## Until 2026-03-24 (Exclusive)
 - Daml Script: Handle new EffectfulRollback errors from the Ledger API
 - Moved Contract keys and QueryNByKey to 2.3-staging (from 2.dev)

sdk/canton/canton_version.bzl

@@ -1,8 +1,8 @@
 # Copyright (c) 2025 Digital Asset (Switzerland) GmbH and/or its affiliates. All rights reserved.
 # SPDX-License-Identifier: Apache-2.0
 
-CANTON_OPEN_SOURCE_TAG = "3.5.0-snapshot.20260324.18425.0.v65b1ee1f"
-CANTON_OPEN_SOURCE_SHA = "sha256:60623bd19bf5e0e5316aeebd6461847ed2890705849f466e1a351549f8d81f96"
+CANTON_OPEN_SOURCE_TAG = "3.5.0-snapshot.20260326.18453.0.ve7a888ff"
+CANTON_OPEN_SOURCE_SHA = "sha256:10e69f534f61d667c3783d3ab6e0406766ca1028e0a95657150f3210b8194b3d"
 
 # Use an alternative canton JAR & artifacts from the local maven cache by setting this to an absolute path
 # Consult canton/README.md

sdk/language-support/java/codegen/src/main/scala/com/digitalasset/daml/lf/codegen/backend/java/inner/ContractClass.scala

@@ -5,6 +5,7 @@ package com.digitalasset.daml.lf.codegen.backend.java.inner
 
 import com.daml.ledger.javaapi
 import ClassGenUtils.{companionFieldName, optional, setOfStrings}
+import com.daml.ledger.javaapi.data.codegen.UnknownTrailingFieldPolicy
 import com.digitalasset.daml.lf.typesig.Type
 import com.squareup.javapoet._
 
@@ -57,6 +58,7 @@ object ContractClass {
         className,
         identity,
         (ClassName get classOf[javaapi.data.CreatedEvent], "event"),
+        (ClassName get classOf[UnknownTrailingFieldPolicy], "policy"),
       )
 
     private[inner] def generateFromIdAndRecord(

sdk/language-support/java/codegen/src/main/scala/com/digitalasset/daml/lf/codegen/backend/java/inner/DecoderClass.scala

@@ -4,13 +4,15 @@
 package com.digitalasset.daml.lf.codegen.backend.java.inner
 
 import com.daml.ledger.javaapi.data._
-import com.daml.ledger.javaapi.data.codegen.ContractCompanion
-import com.daml.ledger.javaapi.data.codegen.ContractDecoder
+import com.daml.ledger.javaapi.data.codegen.{
+  ContractCompanion,
+  ContractDecoder,
+  UnknownTrailingFieldPolicy,
+}
 import com.squareup.javapoet._
 
 import java.util
 import javax.lang.model.element.Modifier
-
 import scala.jdk.CollectionConverters._
 
 object DecoderClass {
@@ -23,6 +25,7 @@ object DecoderClass {
       .addModifiers(Modifier.PUBLIC)
       .addField(decodersField)
       .addMethod(fromCreatedEvent)
+      .addMethod(fromCreatedEventWithPolicy)
       .addMethod(getDecoder)
       .addMethod(getJsonDecoder)
       .addStaticBlock(generateStaticInitializer(templateNames))
@@ -47,7 +50,20 @@ object DecoderClass {
     .returns(contractType)
     .addParameter(ClassName.get(classOf[CreatedEvent]), "event")
     .addException(classOf[IllegalArgumentException])
-    .addStatement("return contractDecoder.fromCreatedEvent(event)")
+    .addStatement(
+      "return fromCreatedEvent(event, $T.STRICT)",
+      classOf[UnknownTrailingFieldPolicy],
+    )
+    .build()
+
+  private val fromCreatedEventWithPolicy = MethodSpec
+    .methodBuilder("fromCreatedEvent")
+    .addModifiers(Modifier.PUBLIC, Modifier.STATIC)
+    .returns(contractType)
+    .addParameter(ClassName.get(classOf[CreatedEvent]), "event")
+    .addParameter(ClassName.get(classOf[UnknownTrailingFieldPolicy]), "policy")
+    .addException(classOf[IllegalArgumentException])
+    .addStatement("return contractDecoder.fromCreatedEvent(event, policy)")
     .build()
 
   private val getDecoder = MethodSpec