AssumeTopicTree Property (_UADataSetSubscriptionDescriptor)

Determines whether the (standard) topic tree will forcibly be used.

Syntax

Visual Basic
C#
C++/CLI

'Declaration
 
Property AssumeTopicTree As Boolean

'Usage
 
Dim instance As _UADataSetSubscriptionDescriptor
Dim value As Boolean
 
instance.AssumeTopicTree = value
 
value = instance.AssumeTopicTree

bool AssumeTopicTree {get; set;}

property bool AssumeTopicTree {
   bool get();
   void set (    bool value);
}

Remarks

Using the topic tree has two major effects:

The software can determine the topic name or filter based on values you give for topic prefix (TopicPrefixHead), publisher Id, writer group name and dataset writer name. You therefore do not need to specify values for properties like OpcLabs.EasyOpc.UA.PubSub.Configuration.UABrokerDataSetReaderTransportParameters.QueueName or OpcLabs.EasyOpc.UA.PubSub.Configuration.UABrokerDataSetReaderTransportParameters.MetaDataQueueName.
The software can fill in values for publisher Id, writer group name and (sometimes) dataset writer name, even if they are absent from the PubSub message, by parsing the originating topic name.

When all queue names (such as OpcLabs.EasyOpc.UA.PubSub.Configuration.UABrokerDataSetReaderTransportParameters.QueueName and OpcLabs.EasyOpc.UA.PubSub.Configuration.UABrokerDataSetReaderTransportParameters.MetaDataQueueName) are unspecified (empty strings, which are the default), and the EffectiveTransportProfileUriString in the ConnectionDescriptor is for transport that uses the topic tree (such as MQTT), the EffectiveAssumeTopicTree becomes true, and you do not have to set AssumeTopicTree to true explicitly in order for the topic tree to be assumed.

CAUTION: With the topic tree (AssumeTopicTree set to true), do not set the queue names by setting values of OpcLabs.EasyOpc.UA.PubSub.Configuration.UABrokerDataSetReaderTransportParameters.QueueName or OpcLabs.EasyOpc.UA.PubSub.Configuration.UABrokerDataSetReaderTransportParameters.MetaDataQueueName, except in very special circumstances. Leave the queue names at their default values, i.e. empty strings. Setting queue names can interfere negatively with the built-in mechanism that determines the proper topic filters.

Requirements

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

Reference

_UADataSetSubscriptionDescriptor Interface
_UADataSetSubscriptionDescriptor Members
EffectiveAssumeTopicTree Property
TopicPrefixHead Property

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