EffectiveAssumeTopicTree Property (_UADataSetSubscriptionDescriptor)

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

Syntax

Visual Basic
C#
C++/CLI

'Declaration
 
ReadOnly Property EffectiveAssumeTopicTree As Boolean

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

bool EffectiveAssumeTopicTree {get;}

property bool EffectiveAssumeTopicTree {
   bool get();
}

Remarks

The (standard) topic tree will be effectively used if either

The AssumeTopicTree property is (explicitly) set to true (the default is false), or
The effective transport profile (as given by the EffectiveTransportProfileUriString in the ConnectionDescriptor) is for transport that uses the topic tree (such as MQTT), and no individual queue names (such as OpcLabs.EasyOpc.UA.PubSub.Configuration.UABrokerDataSetReaderTransportParameters.QueueName and OpcLabs.EasyOpc.UA.PubSub.Configuration.UABrokerDataSetReaderTransportParameters.MetaDataQueueName) were specified.

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.

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.

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
AssumeTopicTree Property
TopicPrefixHead Property

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