Connectivity Software User's Guide and Reference
EasySparkplugConsumer Class
Members  Example 



OpcLabs.EasySparkplugComponents Assembly > OpcLabs.EasySparkplug Namespace : EasySparkplugConsumer Class

The EasySparkplugConsumer object is the main object that allows simple access to data from Sparkplug edge nodes.

The principal members of this object are implementations of the IEasySparkplugConsumer interface.

Object Model
EasySparkplugConsumer ClassSparkplugHostDescriptor ClassStringObjectDictionary Class
Syntax
'Declaration
 
<ExceptionContractAnnotationAttribute(True)>
<CLSCompliantAttribute(True)>
<TypeConverterAttribute(System.ComponentModel.ExpandableObjectConverter)>
<DesignerCategoryAttribute("Component")>
<SerializableAttribute()>
Public NotInheritable Class EasySparkplugConsumer 
   Inherits EasySparkplugConsumerCore
   Implements OpcLabs.BaseLib.ComponentModel.Internal.IComponentCallback, OpcLabs.BaseLib.ComponentModel.Internal.IComponentNotify, OpcLabs.BaseLib.ILicenseInfoProvider, OpcLabs.BaseLib.IValueEquatable, OpcLabs.BaseLib.Licensing.ILicensingContextHolder, OpcLabs.BaseLib.Widgets.ComTypes._NotifyingWidget, OpcLabs.BaseLib.Widgets.ComTypes._Widget, OpcLabs.BaseLib.Widgets.IWidget, IEasySparkplugConsumer, IEasySparkplugNotificationEvents, System.ComponentModel.IComponent, System.ICloneable, System.IDisposable, System.IServiceProvider, System.Runtime.Serialization.ISerializable, System.Xml.Serialization.IXmlSerializable 
'Usage
 
Dim instance As EasySparkplugConsumer
[ExceptionContractAnnotation(true)]
[CLSCompliant(true)]
[TypeConverter(System.ComponentModel.ExpandableObjectConverter)]
[DesignerCategory("Component")]
[Serializable()]
public sealed class EasySparkplugConsumer : EasySparkplugConsumerCore, OpcLabs.BaseLib.ComponentModel.Internal.IComponentCallback, OpcLabs.BaseLib.ComponentModel.Internal.IComponentNotify, OpcLabs.BaseLib.ILicenseInfoProvider, OpcLabs.BaseLib.IValueEquatable, OpcLabs.BaseLib.Licensing.ILicensingContextHolder, OpcLabs.BaseLib.Widgets.ComTypes._NotifyingWidget, OpcLabs.BaseLib.Widgets.ComTypes._Widget, OpcLabs.BaseLib.Widgets.IWidget, IEasySparkplugConsumer, IEasySparkplugNotificationEvents, System.ComponentModel.IComponent, System.ICloneable, System.IDisposable, System.IServiceProvider, System.Runtime.Serialization.ISerializable, System.Xml.Serialization.IXmlSerializable  
[ExceptionContractAnnotation(true)]
[CLSCompliant(true)]
[TypeConverter(System.ComponentModel.ExpandableObjectConverter)]
[DesignerCategory("Component")]
[Serializable()]
public ref class EasySparkplugConsumer sealed : public EasySparkplugConsumerCore, OpcLabs.BaseLib.ComponentModel.Internal.IComponentCallback, OpcLabs.BaseLib.ComponentModel.Internal.IComponentNotify, OpcLabs.BaseLib.ILicenseInfoProvider, OpcLabs.BaseLib.IValueEquatable, OpcLabs.BaseLib.Licensing.ILicensingContextHolder, OpcLabs.BaseLib.Widgets.ComTypes._NotifyingWidget, OpcLabs.BaseLib.Widgets.ComTypes._Widget, OpcLabs.BaseLib.Widgets.IWidget, IEasySparkplugConsumer, IEasySparkplugNotificationEvents, System.ComponentModel.IComponent, System.ICloneable, System.IDisposable, System.IServiceProvider, System.Runtime.Serialization.ISerializable, System.Xml.Serialization.IXmlSerializable  
Remarks

With this object, your code can subscribe to Sparkplug metrics, and/or publish commands.

This object derives from EasySparkplugConsumerCore, and many members are defined there.

 

Sparkplug is a trademark of Eclipse Foundation, Inc. "MQTT" is a trademark of the OASIS Open standards consortium. Other related terms are trademarks of their respective owners. Any use of these terms on this site is for descriptive purposes only and does not imply any sponsorship, endorsement or affiliation.

Example
// This example shows how to subscribe to all metrics of a given edge node and display the name and value of the metric with
// each notification.
//
// In order to publish or observe messages for this example, start the SparkplugEdgeNodeConsoleDemo program first.
//
// Find all latest examples here: https://opclabs.doc-that.com/files/onlinedocs/OPCLabs-ConnectivityStudio/Latest/examples.html .
// Sparkplug examples in C# on GitHub: https://github.com/OPCLabs/Examples-ConnectivityStudio-CSharp .
// Missing some example? Ask us for it on our Online Forums, https://www.opclabs.com/forum/index ! You do not have to own
// a commercial license in order to use Online Forums, and we reply to every post.

using System;
using OpcLabs.EasySparkplug;
using OpcLabs.EasySparkplug.OperationModel;

namespace SparkplugDocExamples.Consumer._EasySparkplugConsumer
{
    partial class SubscribeEdgeNodeMetric
    {
        public static void Overload1()
        {
            // Note that the default port for the "mqtt" scheme is 1883.
            var hostDescriptor = new SparkplugHostDescriptor("mqtt://localhost");

            // Instantiate the consumer object and hook events.
            var consumer = new EasySparkplugConsumer();
            consumer.MetricNotification += consumer_Overload1_MetricNotification;

            Console.WriteLine("Subscribing...");
            // In this example, we specify the precise Sparkplug group ID and edge node ID, but allow any metric name.
            consumer.SubscribeEdgeNodeMetric(hostDescriptor, 
                "easyGroup", "easySparkplugDemo", "#");

            Console.WriteLine("Processing notifications for 20 seconds...");
            System.Threading.Thread.Sleep(20 * 1000);

            Console.WriteLine("Unsubscribing...");
            consumer.UnsubscribeAllMetrics();

            Console.WriteLine("Waiting for 5 seconds...");
            System.Threading.Thread.Sleep(5 * 1000);

            Console.WriteLine("Finished.");
        }


        static void consumer_Overload1_MetricNotification(object sender, EasySparkplugMetricNotificationEventArgs eventArgs)
        {
            // Handle different types of notifications.
            Console.WriteLine();
            switch (eventArgs.NotificationType)
            {
                case SparkplugNotificationType.Connect:
                    Console.WriteLine($"Connected to Sparkplug host, client ID: {eventArgs.ClientId}.");
                    break;
                case SparkplugNotificationType.Disconnect:
                    Console.WriteLine("Disconnected from Sparkplug host.");
                    break;
                case SparkplugNotificationType.Data:
                    Console.WriteLine("Received data from Sparkplug host.");
                    Console.WriteLine($"Metric name: {eventArgs.MetricName}");
                    Console.WriteLine($"Value: {eventArgs.MetricData?.Value}");
                    break;
                case SparkplugNotificationType.Birth:
                    Console.WriteLine("Received birth message from Sparkplug host.");
                    Console.WriteLine($"Metric name: {eventArgs.MetricName}");
                    Console.WriteLine($"Value: {eventArgs.MetricData?.Value}");
                    break;
                case SparkplugNotificationType.Death:
                    Console.WriteLine("Received death message from Sparkplug host.");
                    Console.WriteLine($"Metric name: {eventArgs.MetricName}");
                    break;
            }
            if (!eventArgs.Succeeded)
                Console.WriteLine($"*** Failure: {eventArgs.ErrorMessageBrief}");
        }
    }
}
' This example shows how to subscribe to all metrics of a given edge node and display the name and value of the metric with
' each notification.
'
' In order to publish or observe messages for this example, start the SparkplugEdgeNodeConsoleDemo program first.
'
' Find all latest examples here: https://opclabs.doc-that.com/files/onlinedocs/OPCLabs-ConnectivityStudio/Latest/examples.html .
' Sparkplug examples in C# on GitHub: https://github.com/OPCLabs/Examples-ConnectivityStudio-CSharp .
' Missing some example? Ask us for it on our Online Forums, https://www.opclabs.com/forum/index ! You do not have to own
' a commercial license in order to use Online Forums, and we reply to every post.

Imports OpcLabs.EasySparkplug
Imports OpcLabs.EasySparkplug.OperationModel

Namespace Global.SparkplugDocExamples.Consumer._EasySparkplugConsumer
    Partial Class SubscribeEdgeNodeMetric
        Public Shared Sub Overload1()
            ' Note that the default port for the "mqtt" scheme is 1883.
            Dim hostDescriptor = New SparkplugHostDescriptor("mqtt://localhost")

            ' Instantiate the consumer object and hook events.
            Dim consumer = New EasySparkplugConsumer()
            AddHandler consumer.MetricNotification, AddressOf consumer_Overload1_MetricNotification

            Console.WriteLine("Subscribing...")
            ' In this example, we specify the precise Sparkplug group ID and edge node ID, but allow any metric name.
            consumer.SubscribeEdgeNodeMetric(hostDescriptor,
                "easyGroup", "easySparkplugDemo", "#")

            Console.WriteLine("Processing notifications for 20 seconds...")
            Threading.Thread.Sleep(20 * 1000)

            Console.WriteLine("Unsubscribing...")
            consumer.UnsubscribeAllMetrics()

            Console.WriteLine("Waiting for 5 seconds...")
            Threading.Thread.Sleep(5 * 1000)

            Console.WriteLine("Finished.")
        End Sub

        Private Shared Sub consumer_Overload1_MetricNotification(ByVal sender As Object, ByVal eventArgs As EasySparkplugMetricNotificationEventArgs)
            ' Handle different types of notifications.
            Console.WriteLine()
            Select Case eventArgs.NotificationType
                Case SparkplugNotificationType.Connect
                    Console.WriteLine($"Connected to Sparkplug host, client ID: {eventArgs.ClientId}.")
                Case SparkplugNotificationType.Disconnect
                    Console.WriteLine("Disconnected from Sparkplug host.")
                Case SparkplugNotificationType.Data
                    Console.WriteLine("Received data from Sparkplug host.")
                    Console.WriteLine($"Metric name: {eventArgs.MetricName}")
                    Console.WriteLine($"Value: {eventArgs.MetricData?.Value}")
                Case SparkplugNotificationType.Birth
                    Console.WriteLine("Received birth message from Sparkplug host.")
                    Console.WriteLine($"Metric name: {eventArgs.MetricName}")
                    Console.WriteLine($"Value: {eventArgs.MetricData?.Value}")
                Case SparkplugNotificationType.Death
                    Console.WriteLine("Received death message from Sparkplug host.")
                    Console.WriteLine($"Metric name: {eventArgs.MetricName}")
            End Select
            If Not eventArgs.Succeeded Then
                Console.WriteLine($"*** Failure: {eventArgs.ErrorMessageBrief}")
            End If
        End Sub
    End Class
End Namespace
// This example shows how to specify an implicit host descriptor to be automatically used for subsequent operations on the
// consumer object.
//
// In order to publish or observe messages for this example, start the SparkplugEdgeNodeConsoleDemo program first.
//
// Find all latest examples here: https://opclabs.doc-that.com/files/onlinedocs/OPCLabs-ConnectivityStudio/Latest/examples.html .
// Sparkplug examples in C# on GitHub: https://github.com/OPCLabs/Examples-ConnectivityStudio-CSharp .
// Missing some example? Ask us for it on our Online Forums, https://www.opclabs.com/forum/index ! You do not have to own
// a commercial license in order to use Online Forums, and we reply to every post.

using System;
using OpcLabs.EasySparkplug;
using OpcLabs.EasySparkplug.OperationModel;

namespace SparkplugDocExamples.Consumer._EasySparkplugConsumer
{
    class ImplicitNodeDescriptor
    {
        public static void Main1()
        {
            // Note that the default port for the "mqtt" scheme is 1883.
            var hostDescriptor = new SparkplugHostDescriptor("mqtt://localhost");

            // Instantiate the consumer object and hook events.
            // The implicit host descriptor is specified in the constructor call, and is subsequently used for all
            // operations on this consumer object where the host descriptor is not explicitly specified.
            var consumer = new EasySparkplugConsumer(hostDescriptor);
            consumer.MetricNotification += consumer_Main1_MetricNotification;

            Console.WriteLine("Subscribing...");
            // We are subscribing to two metrics separately, without having to repeat the host descriptor. The implicit
            // host descriptor that was specified in the constructor call is used automatically.
            consumer.SubscribeEdgeNodeMetric("easyGroup", "easySparkplugDemo", "Ramp");
            consumer.SubscribeEdgeNodeMetric("easyGroup", "easySparkplugDemo", "Random");

            Console.WriteLine("Processing notifications for 20 seconds...");
            System.Threading.Thread.Sleep(20 * 1000);

            Console.WriteLine("Unsubscribing...");
            consumer.UnsubscribeAllMetrics();

            Console.WriteLine("Waiting for 5 seconds...");
            System.Threading.Thread.Sleep(5 * 1000);

            Console.WriteLine("Finished.");
        }


        static void consumer_Main1_MetricNotification(object sender, EasySparkplugMetricNotificationEventArgs eventArgs)
        {
            // Handle different types of notifications.
            Console.WriteLine();
            switch (eventArgs.NotificationType)
            {
                case SparkplugNotificationType.Connect:
                    Console.WriteLine($"Connected to Sparkplug host, client ID: {eventArgs.ClientId}.");
                    break;
                case SparkplugNotificationType.Disconnect:
                    Console.WriteLine("Disconnected from Sparkplug host.");
                    break;
                case SparkplugNotificationType.Data:
                    Console.WriteLine("Received data from Sparkplug host.");
                    Console.WriteLine($"Metric name: {eventArgs.MetricName}");
                    Console.WriteLine($"Value: {eventArgs.MetricData?.Value}");
                    break;
                case SparkplugNotificationType.Birth:
                    Console.WriteLine("Received birth message from Sparkplug host.");
                    Console.WriteLine($"Metric name: {eventArgs.MetricName}");
                    Console.WriteLine($"Value: {eventArgs.MetricData?.Value}");
                    break;
                case SparkplugNotificationType.Death:
                    Console.WriteLine("Received death message from Sparkplug host.");
                    Console.WriteLine($"Metric name: {eventArgs.MetricName}");
                    break;
            }
            if (!eventArgs.Succeeded)
                Console.WriteLine($"*** Failure: {eventArgs.ErrorMessageBrief}");
        }
    }
}
Inheritance Hierarchy

System.Object
   System.MarshalByRefObject
      System.ComponentModel.Component
         OpcLabs.BaseLib.Widgets.Widget
            OpcLabs.BaseLib.Widgets.NotifyingWidget
               OpcLabs.EasySparkplug.EasySparkplugConsumerCore
                  OpcLabs.EasySparkplug.EasySparkplugConsumer

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