Problem with new dynamic Type

[johannwesely]

Hello,
in response to :
#1130 (comment)

it is as you suggested i want to read custom structs defined in milo server with milo client. Milo client only can decode when i remove from public static final ExpandedNodeId BINARY_ENCODING_ID = ExpandedNodeId.parse(String.format("nsu=%s;s=%s", ApplicationStrings.TOXCOMUA.getStr(), "\"Root\".\"Types\".\"DataTypes\".\"BaseDataType\".\"Structure\".\"XYPointStruct\".BinaryEncoding")); the .BinaryEncoding on the end otherwise the custom struct couldn't be decoded by the milo client. But UaExpert is able to decode anyways. why is this the case? Greetings Johann

[kevinherron]

I don't know what's wrong by just the description.

You'll have to give me some error messages or something that can reproduce.

I'm able to read the similarly (I assume) defined CustomStructType from the example server by dynamic discovery in the client:

    client.connect();

    // synchronous read request via VariableNode
    UaVariableNode node =
        client
            .getAddressSpace()
            .getVariableNode(new NodeId(2, "HelloWorld/CustomStructTypeVariable"));

    logger.info("DataType={}", node.getDataType());

    // Read the current value
    DataValue value = node.readValue();
    logger.info("Value={}", value);

    Variant variant = value.getValue();
    ExtensionObject xo = (ExtensionObject) variant.getValue();
    assert xo != null;

    DynamicStructType decoded = (DynamicStructType) xo.decode(client.getDynamicEncodingContext());
    logger.info("Decoded={}", decoded);

yields:

[main] INFO org.eclipse.milo.examples.client.ReadWriteCustomDataTypeNodeExample - DataType=NodeId{ns=2, id=DataType.CustomStructType}
[main] INFO org.eclipse.milo.examples.client.ReadWriteCustomDataTypeNodeExample - Value=DataValue{value=Variant{value=ExtensionObject{encoded=ByteString{bytes=[3, 0, 0, 0, 102, 111, 111, 42, 0, 0, 0, 1, 0, 0, 0, 0]}, encodingId=NodeId{ns=2, id=DataType.CustomStructType.BinaryEncoding}}}, status=StatusCode{name=Good, value=0x00000000, quality=good}, sourceTime=DateTime{date=Mon Feb 10 09:34:54 PST 2025, instant=2025-02-10T17:34:54.828300Z}, serverTime=DateTime{date=Mon Feb 10 09:34:55 PST 2025, instant=2025-02-10T17:34:55.982074800Z}}
[main] INFO org.eclipse.milo.examples.client.ReadWriteCustomDataTypeNodeExample - Decoded=DynamicStructType[dataType=ns=2;s=DataType.CustomStructType, members=foo=foo, bar=42, baz=true, customEnumType=DynamicEnumType[dataType=ns=2;s=DataType.CustomEnumType, name=Field0, value=0]]

[johannwesely]

Hello Kevin,

i have for example the same custom structure as in [(https://github.com//discussions/1345#discussion-7553929)]
now when it comes to xo.decode(client.getClient().getDynamicEncodingContext()) i get the error:"no codec registered for encodingId=NodeId{ns=7, id=Types/DataTypes/BaseDataType/Structure/DT_ProcessingTimesDataType/.BinaryEncoding}". But when i remove the .BinaryEncoding from the BINARY_ENCODING_ID in the customstruct DT_ProcessingTimesDataType it works. Beforehand without using the DynamicStructType and using LegacyDataTypeManagerInitializer everything worked as expected. Also my Nodeset is parsed with digitalpetri nodeset Parser from an SIOMe generated Nodeset.xml. I hope this is getting more clearer now.
Greetings Johann

[kevinherron]

On the server side how do you create the ExtensionObject?

e.g.

milo/milo-examples/server-examples/src/main/java/org/eclipse/milo/examples/server/ExampleNamespace.java

Lines 1071 to 1073 in 128cd77

	ExtensionObject xo =
	ExtensionObject.encodeDefaultBinary(
	getServer().getEncodingContext(), value, binaryEncodingId);

It's important that the binary encoding id is used, not the datatype id. One possibility based on what you have described so far is that you have encoded the structure using the datatype id instead, which would explain why a lookup based on the binary encoding id fails until you modify it to remove ".BinaryEncoding", at which point it's the same as the datatype id.