Custom NamespaceUri not available when serializing ExtensionObject

[pzatschl]

Type of issue

• Bug
• Enhancement
• Compliance
• Question
• Help wanted

Current Behavior

When trying to serialize an ExtensionObject to JSON, an Exception is thrown because the corresponding NamespaceURI is not found.

Use case is calling a method with a custom parameter in a KVP array:

When trying to serialize...

...an exception is thrown:

At the same time I don't see any way to configure the context to include my custom namespace.

Line 2881 creation of ExtensionObject:

Already there is only one Namespace present:

Expected Behavior

I would expect for the context at this point to either be configurable or already be containing my custom namespace.
Following the lead of the NamespaceUris being set, one can follow several layers of nesting that amount to setting the value to a string that is hardcoded.

Maybe my approach is wrong altogether?

Steps To Reproduce

OPC_Methoden_Parameter_Test.zip

1. Open the solution attached to this.
2. Run the one unit test in debug
3. Connect via e.g. UaExpert
4. Open Call Window for the Method on "TestObject"
5. Add the structured type "CustomType" to at least one of the KVP array elements
6. Call the Method

Environment

- OS: Windows 11
- Environment: Visual Studio 2022 17.13.0
- Runtime: .NET 6
- Nuget Version: 1.5.375.457
- Component: n/a
- Server: OPCFoundation library based
- Client: UaExpert

Anything else?

No response

[1924006212]

项目报错了看不到信息

[romanett]

@pzatschl I get the Error BadTooManyArguments following your scenario.

Two things i noticed:

• The Keys of the key vallue pair array are not initialized.

• You are using JsonConvert.SerialzeObject. I would expect the use of the integrated JsonDecoder/BinaryDecoder

[1924006212]

How can i create a custom structure Object?

[raserle]

@romanett

• BadTooManyArguments is the result of no implementation of method (return base.Call(context, methodToCall, method, result);) This is not the problem, is the result of simplyfying the test solution.

• The Keys of key value pair are ok, try with strings or empty values will passes the "JsonConvert.SerialzeObject" call

• Using JsonConvert.SerialzeObject is no problem too, internaly he is using the Opc.Ua.JsonDecoder.

I see a problem in BinaryDecoder on create the ExtensionObject from stream.
On calling method from client, OpcServer is used a coder to translate the call(bytes) in objects and on "Opc.Ua.BinaryDecoder.ReadExtensionObject()" an ExtensionObject is instanziated.
In this chain i missing the correct Context, only a default is set. In this default are no actuall used namespaces. Thats the error we see.

I show you the callstack from BinaryDecoder -> new ExtensionObject();

Opc.Ua.BinaryDecoder

Opc.Ua.ExtensionObject

Opc.Ua.MessageContextExtension

Opc.Ua.ServiceMessageContext

Opc.Ua.NamespaceTable

Possible Solution?

A new constructor in ExtensionObject

and a change in ExtensionObject
Remove this line.

[romanett]

@raserle thanks for the insights. It seems BaseComplexType & Variant could have the same Issue.