// This example shows how to subscribe to changes of a monitored item with data change filter.
 
using System;
using OpcLabs.EasyOpc.UA;
using OpcLabs.EasyOpc.UA.OperationModel;
 
namespace UADocExamples._EasyUAClient
{
    partial class SubscribeDataChange
    {
        public static void Filter()
        {
            UAEndpointDescriptor endpointDescriptor =
                "opc.tcp://opcua.demo-this.com:51210/UA/SampleServer";
            // or "http://opcua.demo-this.com:51211/UA/SampleServer" (not in .NET Standard)
            // or "https://opcua.demo-this.com:51212/UA/SampleServer/"
 
            // Instantiate the client object and hook events
            var client = new EasyUAClient();
            client.DataChangeNotification += client_DataChangeNotification_Filter;
 
            Console.WriteLine("Subscribing...");
            // Report a notification if either the StatusCode or the value change. 
            // The UADataChangeTrigger has an implicit conversion to UADataChangeFilter and can thus be used in its place.
            client.SubscribeDataChange(endpointDescriptor, "nsu=http://test.org/UA/Data/;i=10853", 1000, 
                UADataChangeTrigger.StatusValue);
 
            Console.WriteLine("Processing data change events for 20 seconds...");
            System.Threading.Thread.Sleep(20 * 1000);
 
            Console.WriteLine("Unsubscribing...");
            client.UnsubscribeAllMonitoredItems();
 
            Console.WriteLine("Waiting for 5 seconds...");
            System.Threading.Thread.Sleep(5 * 1000);
        }
 
        static void client_DataChangeNotification_Filter(object sender, EasyUADataChangeNotificationEventArgs e)
        {
            // Display value
            if (e.Succeeded)
                Console.WriteLine("Value: {0}", e.AttributeData.Value);
            else
                Console.WriteLine("*** Failure: {0}", e.ErrorMessageBrief);
        }
    }
}

// This example shows how to subscribe to changes of multiple monitored items and use a data change filter.
 
using System;
using OpcLabs.EasyOpc.UA;
using OpcLabs.EasyOpc.UA.OperationModel;
 
namespace UADocExamples._EasyUAClient
{
    partial class SubscribeMultipleMonitoredItems
    {
        public static void Filter()
        {
            UAEndpointDescriptor endpointDescriptor =
                "opc.tcp://opcua.demo-this.com:51210/UA/SampleServer";
            // or "http://opcua.demo-this.com:51211/UA/SampleServer" (not in .NET Standard)
            // or "https://opcua.demo-this.com:51212/UA/SampleServer/"
 
            // Instantiate the client object and hook events
            var client = new EasyUAClient();
            client.DataChangeNotification += client_DataChangeNotification_Filter;
 
            Console.WriteLine("Subscribing...");
            // Report a notification if either the StatusCode or the value change. 
            // The UADataChangeTrigger has an implicit conversion to UADataChangeFilter and can thus be used in its place.
            client.SubscribeMultipleMonitoredItems(new[]
                {
                    new EasyUAMonitoredItemArguments(null, endpointDescriptor, 
                        "nsu=http://test.org/UA/Data/;i=10845", 
                        new UAMonitoringParameters(1000, UADataChangeTrigger.StatusValue)),
                    new EasyUAMonitoredItemArguments(null, endpointDescriptor, 
                        "nsu=http://test.org/UA/Data/;i=10853", 
                        new UAMonitoringParameters(1000, UADataChangeTrigger.StatusValue)),
                    new EasyUAMonitoredItemArguments(null, endpointDescriptor, 
                        "nsu=http://test.org/UA/Data/;i=10855", 
                        new UAMonitoringParameters(1000, UADataChangeTrigger.StatusValue))
                });
 
            Console.WriteLine("Processing monitored item changed events for 10 seconds...");
            System.Threading.Thread.Sleep(10 * 1000);
 
            Console.WriteLine("Unsubscribing...");
            client.UnsubscribeAllMonitoredItems();
 
            Console.WriteLine("Waiting for 5 seconds...");
            System.Threading.Thread.Sleep(5 * 1000);
        }
 
        static void client_DataChangeNotification_Filter(object sender, EasyUADataChangeNotificationEventArgs e)
        {
            // Display value
            if (e.Succeeded)
                Console.WriteLine("{0}: {1}", e.Arguments.NodeDescriptor, e.AttributeData.Value);
            else
                Console.WriteLine("{0} *** Failure: {1}", e.Arguments.NodeDescriptor, e.ErrorMessageBrief);
        }
    }
}