OPC Studio User's Guide and Reference
HasExtensionField Method (_UAReadOnlyPubSubConfiguration)



OpcLabs.EasyOpcUA Assembly > OpcLabs.EasyOpc.UA.PubSub.Configuration.ComTypes Namespace > _UAReadOnlyPubSubConfiguration Interface : HasExtensionField Method
The name of the published dataset.

The value of this parameter can be null (Nothing in Visual Basic).

An optional path to the folder that contains the published dataset.

The value of this parameter can be null (Nothing in Visual Basic).

The individual elements of the parameter value cannot be null (Nothing in Visual Basic).

The qualified name of the extension field.

Because the OpcLabs.EasyOpc.UA.AddressSpace.UAQualifiedName has an implicit conversion from System.String, in languages that support implicit conversion operators (such as C# or VB.NET), you can simply use a string (representing the expanded text of the qualified name) in place of this parameter, and the corresponding OPC UA qualified name will be constructed automatically. When the implicit conversion operators are not supported (such as with Python.NET), you can use the OpcLabs.EasyOpc.UA.AddressSpace.UAQualifiedName.UAQualifiedName Constructor(String) constructor instead.

The value of this parameter cannot be null (Nothing in Visual Basic).

Determines whether the published dataset has a specified extension field.
Syntax
'Declaration
 
Function HasExtensionField( _
   ByVal publishedDataSetName As String, _
   ByVal dataSetFolderPath As Object, _
   ByVal extensionFieldQualifiedName As Object _
) As Boolean
'Usage
 
Dim instance As _UAReadOnlyPubSubConfiguration
Dim publishedDataSetName As String
Dim dataSetFolderPath As Object
Dim extensionFieldQualifiedName As Object
Dim value As Boolean
 
value = instance.HasExtensionField(publishedDataSetName, dataSetFolderPath, extensionFieldQualifiedName)

Parameters

publishedDataSetName
The name of the published dataset.

The value of this parameter can be null (Nothing in Visual Basic).

dataSetFolderPath
An optional path to the folder that contains the published dataset.

The value of this parameter can be null (Nothing in Visual Basic).

The individual elements of the parameter value cannot be null (Nothing in Visual Basic).

extensionFieldQualifiedName
The qualified name of the extension field.

Because the OpcLabs.EasyOpc.UA.AddressSpace.UAQualifiedName has an implicit conversion from System.String, in languages that support implicit conversion operators (such as C# or VB.NET), you can simply use a string (representing the expanded text of the qualified name) in place of this parameter, and the corresponding OPC UA qualified name will be constructed automatically. When the implicit conversion operators are not supported (such as with Python.NET), you can use the OpcLabs.EasyOpc.UA.AddressSpace.UAQualifiedName.UAQualifiedName Constructor(String) constructor instead.

The value of this parameter cannot be null (Nothing in Visual Basic).

Return Value

Returns true if the published dataset has the extension field extensionFieldQualifiedName; returns false otherwise.
Exceptions
ExceptionDescription
An error has occurred during application execution.

A null reference (Nothing in Visual Basic) is passed to a method that does not accept it as a valid argument.

This is a usage error, i.e. it will never occur (the exception will not be thrown) in a correctly written program. Your code should not catch this exception.

The OPC UA operation has failed. This operation exception in uniformly used to allow common handling of various kinds of errors. The System.Exception.InnerException always contains information about the actual error cause.

This is an operation error that depends on factors external to your program, and thus cannot be always avoided. Your code must handle it appropriately.

There is a logical error in the OPC UA operation.

This is an operation error that depends on factors external to your program, and thus cannot be always avoided. Your code must handle it appropriately.

Remarks

This member or type is for use from COM. It is not meant to be used from .NET or Python. Refer to the corresponding .NET member or type instead, if you are developing in .NET or Python.

Requirements

Target Platforms: .NET Framework: Windows 10 (selected versions), Windows 11 (selected versions), Windows Server 2016, Windows Server 2022; .NET: Linux, macOS, Microsoft Windows

See Also