[plc4x] branch feature/mspec-ng updated: fix(plc4j/spi): implement assert field

[sr...@apache.org]

This is an automated email from the ASF dual-hosted git repository.

sruehl pushed a commit to branch feature/mspec-ng
in repository https://gitbox.apache.org/repos/asf/plc4x.git


The following commit(s) were added to refs/heads/feature/mspec-ng by this push:
     new e99fbc2  fix(plc4j/spi): implement assert field
e99fbc2 is described below

commit e99fbc21c9a74d76ac3d0fe65d267fb71b3c0580
Author: Sebastian Rühl <sr...@apache.org>
AuthorDate: Fri Oct 8 15:08:36 2021 +0200

    fix(plc4j/spi): implement assert field
---
 .../plc4x/java/spi/codegen/fields/FieldReaderAbstract.java     |  3 +--
 .../apache/plc4x/java/spi/codegen/fields/FieldReaderArray.java |  3 +--
 .../plc4x/java/spi/codegen/fields/FieldReaderAssert.java       | 10 ++++++++--
 .../plc4x/java/spi/codegen/fields/FieldReaderChecksum.java     |  3 +--
 .../apache/plc4x/java/spi/codegen/fields/FieldReaderConst.java |  3 +--
 .../java/spi/codegen/fields/FieldReaderDiscriminator.java      |  3 +--
 .../apache/plc4x/java/spi/codegen/fields/FieldReaderEnum.java  |  3 +--
 .../plc4x/java/spi/codegen/fields/FieldReaderImplicit.java     |  3 +--
 .../plc4x/java/spi/codegen/fields/FieldReaderManual.java       |  3 +--
 .../plc4x/java/spi/codegen/fields/FieldReaderManualArray.java  |  3 +--
 .../plc4x/java/spi/codegen/fields/FieldReaderOptional.java     |  5 ++---
 .../plc4x/java/spi/codegen/fields/FieldReaderPadding.java      |  3 +--
 .../plc4x/java/spi/codegen/fields/FieldReaderReserved.java     |  3 +--
 .../plc4x/java/spi/codegen/fields/FieldReaderTypeSwitch.java   |  3 +--
 .../plc4x/java/spi/codegen/fields/FieldReaderUnknown.java      |  3 +--
 .../plc4x/java/spi/codegen/fields/FieldReaderVirtual.java      |  3 +--
 16 files changed, 24 insertions(+), 33 deletions(-)

diff --git a/plc4j/spi/src/main/java/org/apache/plc4x/java/spi/codegen/fields/FieldReaderAbstract.java b/plc4j/spi/src/main/java/org/apache/plc4x/java/spi/codegen/fields/FieldReaderAbstract.java
index 6618671..cd9e3c7 100644
--- a/plc4j/spi/src/main/java/org/apache/plc4x/java/spi/codegen/fields/FieldReaderAbstract.java
+++ b/plc4j/spi/src/main/java/org/apache/plc4x/java/spi/codegen/fields/FieldReaderAbstract.java
@@ -18,7 +18,6 @@
  */
 package org.apache.plc4x.java.spi.codegen.fields;
 
-import org.apache.plc4x.java.spi.codegen.WithOption;
 import org.apache.plc4x.java.spi.codegen.io.DataReader;
 import org.apache.plc4x.java.spi.generation.ParseException;
 import org.apache.plc4x.java.spi.generation.WithReaderArgs;
@@ -31,7 +30,7 @@ public class FieldReaderAbstract<T> implements FieldReader<T> {
 
     @Override
     public T readField(String logicalName, DataReader<T> dataReader, WithReaderArgs... readerArgs) throws ParseException {
-        throw new IllegalStateException("not possible with optional field");
+        return switchByteOrderIfNecessary(() -> dataReader.read(logicalName, readerArgs), dataReader, extractByteOder(readerArgs).orElse(null));
     }
 
 }
diff --git a/plc4j/spi/src/main/java/org/apache/plc4x/java/spi/codegen/fields/FieldReaderArray.java b/plc4j/spi/src/main/java/org/apache/plc4x/java/spi/codegen/fields/FieldReaderArray.java
index 99f37a9..27ba337 100644
--- a/plc4j/spi/src/main/java/org/apache/plc4x/java/spi/codegen/fields/FieldReaderArray.java
+++ b/plc4j/spi/src/main/java/org/apache/plc4x/java/spi/codegen/fields/FieldReaderArray.java
@@ -18,7 +18,6 @@
  */
 package org.apache.plc4x.java.spi.codegen.fields;
 
-import org.apache.plc4x.java.spi.codegen.WithOption;
 import org.apache.plc4x.java.spi.codegen.io.DataReader;
 import org.apache.plc4x.java.spi.generation.ParseException;
 import org.apache.plc4x.java.spi.generation.WithReaderArgs;
@@ -31,7 +30,7 @@ public class FieldReaderArray<T> implements FieldReader<T> {
 
     @Override
     public T readField(String logicalName, DataReader<T> dataReader, WithReaderArgs... readerArgs) throws ParseException {
-        throw new IllegalStateException("not possible with optional field");
+        return switchByteOrderIfNecessary(() -> dataReader.read(logicalName, readerArgs), dataReader, extractByteOder(readerArgs).orElse(null));
     }
 
 }
diff --git a/plc4j/spi/src/main/java/org/apache/plc4x/java/spi/codegen/fields/FieldReaderAssert.java b/plc4j/spi/src/main/java/org/apache/plc4x/java/spi/codegen/fields/FieldReaderAssert.java
index 01b85fa..44594e8 100644
--- a/plc4j/spi/src/main/java/org/apache/plc4x/java/spi/codegen/fields/FieldReaderAssert.java
+++ b/plc4j/spi/src/main/java/org/apache/plc4x/java/spi/codegen/fields/FieldReaderAssert.java
@@ -18,8 +18,8 @@
  */
 package org.apache.plc4x.java.spi.codegen.fields;
 
-import org.apache.plc4x.java.spi.codegen.WithOption;
 import org.apache.plc4x.java.spi.codegen.io.DataReader;
+import org.apache.plc4x.java.spi.generation.ParseAssertException;
 import org.apache.plc4x.java.spi.generation.ParseException;
 import org.apache.plc4x.java.spi.generation.WithReaderArgs;
 import org.slf4j.Logger;
@@ -31,7 +31,13 @@ public class FieldReaderAssert<T> implements FieldReader<T> {
 
     @Override
     public T readField(String logicalName, DataReader<T> dataReader, WithReaderArgs... readerArgs) throws ParseException {
-        throw new IllegalStateException("not possible with optional field");
+        throw new IllegalStateException("not possible with assert field");
     }
 
+    public T readAssertField(String logicalName, DataReader<T> dataReader, boolean condition, WithReaderArgs... readerArgs) throws ParseException {
+        if (!condition) {
+            throw new ParseAssertException("Doesn't meet expectations");
+        }
+        return dataReader.read(logicalName, readerArgs);
+    }
 }
diff --git a/plc4j/spi/src/main/java/org/apache/plc4x/java/spi/codegen/fields/FieldReaderChecksum.java b/plc4j/spi/src/main/java/org/apache/plc4x/java/spi/codegen/fields/FieldReaderChecksum.java
index 321a48b..10a8dad 100644
--- a/plc4j/spi/src/main/java/org/apache/plc4x/java/spi/codegen/fields/FieldReaderChecksum.java
+++ b/plc4j/spi/src/main/java/org/apache/plc4x/java/spi/codegen/fields/FieldReaderChecksum.java
@@ -18,7 +18,6 @@
  */
 package org.apache.plc4x.java.spi.codegen.fields;
 
-import org.apache.plc4x.java.spi.codegen.WithOption;
 import org.apache.plc4x.java.spi.codegen.io.DataReader;
 import org.apache.plc4x.java.spi.generation.ParseException;
 import org.apache.plc4x.java.spi.generation.WithReaderArgs;
@@ -31,7 +30,7 @@ public class FieldReaderChecksum<T> implements FieldReader<T> {
 
     @Override
     public T readField(String logicalName, DataReader<T> dataReader, WithReaderArgs... readerArgs) throws ParseException {
-        throw new IllegalStateException("not possible with optional field");
+        return switchByteOrderIfNecessary(() -> dataReader.read(logicalName, readerArgs), dataReader, extractByteOder(readerArgs).orElse(null));
     }
 
 }
diff --git a/plc4j/spi/src/main/java/org/apache/plc4x/java/spi/codegen/fields/FieldReaderConst.java b/plc4j/spi/src/main/java/org/apache/plc4x/java/spi/codegen/fields/FieldReaderConst.java
index e41d3f3..a1cf18c 100644
--- a/plc4j/spi/src/main/java/org/apache/plc4x/java/spi/codegen/fields/FieldReaderConst.java
+++ b/plc4j/spi/src/main/java/org/apache/plc4x/java/spi/codegen/fields/FieldReaderConst.java
@@ -18,7 +18,6 @@
  */
 package org.apache.plc4x.java.spi.codegen.fields;
 
-import org.apache.plc4x.java.spi.codegen.WithOption;
 import org.apache.plc4x.java.spi.codegen.io.DataReader;
 import org.apache.plc4x.java.spi.generation.ParseException;
 import org.apache.plc4x.java.spi.generation.WithReaderArgs;
@@ -31,7 +30,7 @@ public class FieldReaderConst<T> implements FieldReader<T> {
 
     @Override
     public T readField(String logicalName, DataReader<T> dataReader, WithReaderArgs... readerArgs) throws ParseException {
-        throw new IllegalStateException("not possible with optional field");
+        return switchByteOrderIfNecessary(() -> dataReader.read(logicalName, readerArgs), dataReader, extractByteOder(readerArgs).orElse(null));
     }
 
 }
diff --git a/plc4j/spi/src/main/java/org/apache/plc4x/java/spi/codegen/fields/FieldReaderDiscriminator.java b/plc4j/spi/src/main/java/org/apache/plc4x/java/spi/codegen/fields/FieldReaderDiscriminator.java
index 0f906dc..2a910a7 100644
--- a/plc4j/spi/src/main/java/org/apache/plc4x/java/spi/codegen/fields/FieldReaderDiscriminator.java
+++ b/plc4j/spi/src/main/java/org/apache/plc4x/java/spi/codegen/fields/FieldReaderDiscriminator.java
@@ -18,7 +18,6 @@
  */
 package org.apache.plc4x.java.spi.codegen.fields;
 
-import org.apache.plc4x.java.spi.codegen.WithOption;
 import org.apache.plc4x.java.spi.codegen.io.DataReader;
 import org.apache.plc4x.java.spi.generation.ParseException;
 import org.apache.plc4x.java.spi.generation.WithReaderArgs;
@@ -31,7 +30,7 @@ public class FieldReaderDiscriminator<T> implements FieldReader<T> {
 
     @Override
     public T readField(String logicalName, DataReader<T> dataReader, WithReaderArgs... readerArgs) throws ParseException {
-        throw new IllegalStateException("not possible with optional field");
+        return switchByteOrderIfNecessary(() -> dataReader.read(logicalName, readerArgs), dataReader, extractByteOder(readerArgs).orElse(null));
     }
 
 }
diff --git a/plc4j/spi/src/main/java/org/apache/plc4x/java/spi/codegen/fields/FieldReaderEnum.java b/plc4j/spi/src/main/java/org/apache/plc4x/java/spi/codegen/fields/FieldReaderEnum.java
index 755310b..5761a6f 100644
--- a/plc4j/spi/src/main/java/org/apache/plc4x/java/spi/codegen/fields/FieldReaderEnum.java
+++ b/plc4j/spi/src/main/java/org/apache/plc4x/java/spi/codegen/fields/FieldReaderEnum.java
@@ -18,7 +18,6 @@
  */
 package org.apache.plc4x.java.spi.codegen.fields;
 
-import org.apache.plc4x.java.spi.codegen.WithOption;
 import org.apache.plc4x.java.spi.codegen.io.DataReader;
 import org.apache.plc4x.java.spi.generation.ParseException;
 import org.apache.plc4x.java.spi.generation.WithReaderArgs;
@@ -31,7 +30,7 @@ public class FieldReaderEnum<T> implements FieldReader<T> {
 
     @Override
     public T readField(String logicalName, DataReader<T> dataReader, WithReaderArgs... readerArgs) throws ParseException {
-        throw new IllegalStateException("not possible with optional field");
+        return switchByteOrderIfNecessary(() -> dataReader.read(logicalName, readerArgs), dataReader, extractByteOder(readerArgs).orElse(null));
     }
 
 }
diff --git a/plc4j/spi/src/main/java/org/apache/plc4x/java/spi/codegen/fields/FieldReaderImplicit.java b/plc4j/spi/src/main/java/org/apache/plc4x/java/spi/codegen/fields/FieldReaderImplicit.java
index c68e1bc..437b1e1 100644
--- a/plc4j/spi/src/main/java/org/apache/plc4x/java/spi/codegen/fields/FieldReaderImplicit.java
+++ b/plc4j/spi/src/main/java/org/apache/plc4x/java/spi/codegen/fields/FieldReaderImplicit.java
@@ -18,7 +18,6 @@
  */
 package org.apache.plc4x.java.spi.codegen.fields;
 
-import org.apache.plc4x.java.spi.codegen.WithOption;
 import org.apache.plc4x.java.spi.codegen.io.DataReader;
 import org.apache.plc4x.java.spi.generation.ParseException;
 import org.apache.plc4x.java.spi.generation.WithReaderArgs;
@@ -31,7 +30,7 @@ public class FieldReaderImplicit<T> implements FieldReader<T> {
 
     @Override
     public T readField(String logicalName, DataReader<T> dataReader, WithReaderArgs... readerArgs) throws ParseException {
-        throw new IllegalStateException("not possible with optional field");
+        return switchByteOrderIfNecessary(() -> dataReader.read(logicalName, readerArgs), dataReader, extractByteOder(readerArgs).orElse(null));
     }
 
 }
diff --git a/plc4j/spi/src/main/java/org/apache/plc4x/java/spi/codegen/fields/FieldReaderManual.java b/plc4j/spi/src/main/java/org/apache/plc4x/java/spi/codegen/fields/FieldReaderManual.java
index b3e8cda..dd22f4b 100644
--- a/plc4j/spi/src/main/java/org/apache/plc4x/java/spi/codegen/fields/FieldReaderManual.java
+++ b/plc4j/spi/src/main/java/org/apache/plc4x/java/spi/codegen/fields/FieldReaderManual.java
@@ -18,7 +18,6 @@
  */
 package org.apache.plc4x.java.spi.codegen.fields;
 
-import org.apache.plc4x.java.spi.codegen.WithOption;
 import org.apache.plc4x.java.spi.codegen.io.DataReader;
 import org.apache.plc4x.java.spi.generation.ParseException;
 import org.apache.plc4x.java.spi.generation.WithReaderArgs;
@@ -31,7 +30,7 @@ public class FieldReaderManual<T> implements FieldReader<T> {
 
     @Override
     public T readField(String logicalName, DataReader<T> dataReader, WithReaderArgs... readerArgs) throws ParseException {
-        throw new IllegalStateException("not possible with optional field");
+        return switchByteOrderIfNecessary(() -> dataReader.read(logicalName, readerArgs), dataReader, extractByteOder(readerArgs).orElse(null));
     }
 
 }
diff --git a/plc4j/spi/src/main/java/org/apache/plc4x/java/spi/codegen/fields/FieldReaderManualArray.java b/plc4j/spi/src/main/java/org/apache/plc4x/java/spi/codegen/fields/FieldReaderManualArray.java
index c4b5f6a..045f2bf 100644
--- a/plc4j/spi/src/main/java/org/apache/plc4x/java/spi/codegen/fields/FieldReaderManualArray.java
+++ b/plc4j/spi/src/main/java/org/apache/plc4x/java/spi/codegen/fields/FieldReaderManualArray.java
@@ -18,7 +18,6 @@
  */
 package org.apache.plc4x.java.spi.codegen.fields;
 
-import org.apache.plc4x.java.spi.codegen.WithOption;
 import org.apache.plc4x.java.spi.codegen.io.DataReader;
 import org.apache.plc4x.java.spi.generation.ParseException;
 import org.apache.plc4x.java.spi.generation.WithReaderArgs;
@@ -31,7 +30,7 @@ public class FieldReaderManualArray<T> implements FieldReader<T> {
 
     @Override
     public T readField(String logicalName, DataReader<T> dataReader, WithReaderArgs... readerArgs) throws ParseException {
-        throw new IllegalStateException("not possible with optional field");
+        return switchByteOrderIfNecessary(() -> dataReader.read(logicalName, readerArgs), dataReader, extractByteOder(readerArgs).orElse(null));
     }
 
 }
diff --git a/plc4j/spi/src/main/java/org/apache/plc4x/java/spi/codegen/fields/FieldReaderOptional.java b/plc4j/spi/src/main/java/org/apache/plc4x/java/spi/codegen/fields/FieldReaderOptional.java
index f3b0332..e770a92 100644
--- a/plc4j/spi/src/main/java/org/apache/plc4x/java/spi/codegen/fields/FieldReaderOptional.java
+++ b/plc4j/spi/src/main/java/org/apache/plc4x/java/spi/codegen/fields/FieldReaderOptional.java
@@ -18,7 +18,6 @@
  */
 package org.apache.plc4x.java.spi.codegen.fields;
 
-import org.apache.plc4x.java.spi.codegen.WithOption;
 import org.apache.plc4x.java.spi.codegen.io.DataReader;
 import org.apache.plc4x.java.spi.generation.ParseAssertException;
 import org.apache.plc4x.java.spi.generation.ParseException;
@@ -35,7 +34,7 @@ public class FieldReaderOptional<T> implements FieldReader<T> {
         throw new IllegalStateException("not possible with optional field");
     }
 
-    public T readOptionalField(String logicalName, DataReader<T> dataReader, boolean condition, WithOption... options) throws ParseException {
+    public T readOptionalField(String logicalName, DataReader<T> dataReader, boolean condition, WithReaderArgs... readerArgs) throws ParseException {
         if (!condition) {
             LOGGER.debug("Condition doesnt match for field {}", logicalName);
             return null;
@@ -43,7 +42,7 @@ public class FieldReaderOptional<T> implements FieldReader<T> {
 
         int curPos = dataReader.getPos();
         try {
-            return dataReader.read(logicalName, options);
+            return dataReader.read(logicalName, readerArgs);
         } catch (ParseAssertException e) {
             LOGGER.trace("Assertion doesnt match for field {}", logicalName, e);
             dataReader.setPos(curPos);
diff --git a/plc4j/spi/src/main/java/org/apache/plc4x/java/spi/codegen/fields/FieldReaderPadding.java b/plc4j/spi/src/main/java/org/apache/plc4x/java/spi/codegen/fields/FieldReaderPadding.java
index c9747e0..0add5c9 100644
--- a/plc4j/spi/src/main/java/org/apache/plc4x/java/spi/codegen/fields/FieldReaderPadding.java
+++ b/plc4j/spi/src/main/java/org/apache/plc4x/java/spi/codegen/fields/FieldReaderPadding.java
@@ -18,7 +18,6 @@
  */
 package org.apache.plc4x.java.spi.codegen.fields;
 
-import org.apache.plc4x.java.spi.codegen.WithOption;
 import org.apache.plc4x.java.spi.codegen.io.DataReader;
 import org.apache.plc4x.java.spi.generation.ParseException;
 import org.apache.plc4x.java.spi.generation.WithReaderArgs;
@@ -31,7 +30,7 @@ public class FieldReaderPadding<T> implements FieldReader<T> {
 
     @Override
     public T readField(String logicalName, DataReader<T> dataReader, WithReaderArgs... readerArgs) throws ParseException {
-        throw new IllegalStateException("not possible with optional field");
+        return switchByteOrderIfNecessary(() -> dataReader.read(logicalName, readerArgs), dataReader, extractByteOder(readerArgs).orElse(null));
     }
 
 }
diff --git a/plc4j/spi/src/main/java/org/apache/plc4x/java/spi/codegen/fields/FieldReaderReserved.java b/plc4j/spi/src/main/java/org/apache/plc4x/java/spi/codegen/fields/FieldReaderReserved.java
index 4e8913e..68ed531 100644
--- a/plc4j/spi/src/main/java/org/apache/plc4x/java/spi/codegen/fields/FieldReaderReserved.java
+++ b/plc4j/spi/src/main/java/org/apache/plc4x/java/spi/codegen/fields/FieldReaderReserved.java
@@ -18,7 +18,6 @@
  */
 package org.apache.plc4x.java.spi.codegen.fields;
 
-import org.apache.plc4x.java.spi.codegen.WithOption;
 import org.apache.plc4x.java.spi.codegen.io.DataReader;
 import org.apache.plc4x.java.spi.generation.ParseException;
 import org.apache.plc4x.java.spi.generation.WithReaderArgs;
@@ -31,7 +30,7 @@ public class FieldReaderReserved<T> implements FieldReader<T> {
 
     @Override
     public T readField(String logicalName, DataReader<T> dataReader, WithReaderArgs... readerArgs) throws ParseException {
-        throw new IllegalStateException("not possible with optional field");
+        return switchByteOrderIfNecessary(() -> dataReader.read(logicalName, readerArgs), dataReader, extractByteOder(readerArgs).orElse(null));
     }
 
 }
diff --git a/plc4j/spi/src/main/java/org/apache/plc4x/java/spi/codegen/fields/FieldReaderTypeSwitch.java b/plc4j/spi/src/main/java/org/apache/plc4x/java/spi/codegen/fields/FieldReaderTypeSwitch.java
index 44f78c1..f7fdac0 100644
--- a/plc4j/spi/src/main/java/org/apache/plc4x/java/spi/codegen/fields/FieldReaderTypeSwitch.java
+++ b/plc4j/spi/src/main/java/org/apache/plc4x/java/spi/codegen/fields/FieldReaderTypeSwitch.java
@@ -18,7 +18,6 @@
  */
 package org.apache.plc4x.java.spi.codegen.fields;
 
-import org.apache.plc4x.java.spi.codegen.WithOption;
 import org.apache.plc4x.java.spi.codegen.io.DataReader;
 import org.apache.plc4x.java.spi.generation.ParseException;
 import org.apache.plc4x.java.spi.generation.WithReaderArgs;
@@ -31,7 +30,7 @@ public class FieldReaderTypeSwitch<T> implements FieldReader<T> {
 
     @Override
     public T readField(String logicalName, DataReader<T> dataReader, WithReaderArgs... readerArgs) throws ParseException {
-        throw new IllegalStateException("not possible with optional field");
+        return switchByteOrderIfNecessary(() -> dataReader.read(logicalName, readerArgs), dataReader, extractByteOder(readerArgs).orElse(null));
     }
 
 }
diff --git a/plc4j/spi/src/main/java/org/apache/plc4x/java/spi/codegen/fields/FieldReaderUnknown.java b/plc4j/spi/src/main/java/org/apache/plc4x/java/spi/codegen/fields/FieldReaderUnknown.java
index 0944a0d..711a203 100644
--- a/plc4j/spi/src/main/java/org/apache/plc4x/java/spi/codegen/fields/FieldReaderUnknown.java
+++ b/plc4j/spi/src/main/java/org/apache/plc4x/java/spi/codegen/fields/FieldReaderUnknown.java
@@ -18,7 +18,6 @@
  */
 package org.apache.plc4x.java.spi.codegen.fields;
 
-import org.apache.plc4x.java.spi.codegen.WithOption;
 import org.apache.plc4x.java.spi.codegen.io.DataReader;
 import org.apache.plc4x.java.spi.generation.ParseException;
 import org.apache.plc4x.java.spi.generation.WithReaderArgs;
@@ -31,7 +30,7 @@ public class FieldReaderUnknown<T> implements FieldReader<T> {
 
     @Override
     public T readField(String logicalName, DataReader<T> dataReader, WithReaderArgs... readerArgs) throws ParseException {
-        throw new IllegalStateException("not possible with optional field");
+        return switchByteOrderIfNecessary(() -> dataReader.read(logicalName, readerArgs), dataReader, extractByteOder(readerArgs).orElse(null));
     }
 
 }
diff --git a/plc4j/spi/src/main/java/org/apache/plc4x/java/spi/codegen/fields/FieldReaderVirtual.java b/plc4j/spi/src/main/java/org/apache/plc4x/java/spi/codegen/fields/FieldReaderVirtual.java
index 00dcbd3..61a8b21 100644
--- a/plc4j/spi/src/main/java/org/apache/plc4x/java/spi/codegen/fields/FieldReaderVirtual.java
+++ b/plc4j/spi/src/main/java/org/apache/plc4x/java/spi/codegen/fields/FieldReaderVirtual.java
@@ -18,7 +18,6 @@
  */
 package org.apache.plc4x.java.spi.codegen.fields;
 
-import org.apache.plc4x.java.spi.codegen.WithOption;
 import org.apache.plc4x.java.spi.codegen.io.DataReader;
 import org.apache.plc4x.java.spi.generation.ParseException;
 import org.apache.plc4x.java.spi.generation.WithReaderArgs;
@@ -31,7 +30,7 @@ public class FieldReaderVirtual<T> implements FieldReader<T> {
 
     @Override
     public T readField(String logicalName, DataReader<T> dataReader, WithReaderArgs... readerArgs) throws ParseException {
-        throw new IllegalStateException("not possible with optional field");
+        return switchByteOrderIfNecessary(() -> dataReader.read(logicalName, readerArgs), dataReader, extractByteOder(readerArgs).orElse(null));
     }
 
 }