Reactive Networking (RxNetworking) Configuration

Introduction

By design, this library is a plug-in or using modern terminology application composition part of the RxNetworking application described in Reactive Networking (RxNetworking) of Semantic-Data Library. At run time it can be used as the primary source of configuration for any standalone OOI Reactive Application and UA Server supporting PubSub role. It provides a basic implementation of the IConfigurationDataFactory. The idea behind this interface implementation is late binding - to allow the adoption of a new functionality against inevitable requirement changes after deploying a solution based on the RxNetworking application.

In this case, the application configuration may:

• be derived from the proposed one

• be expanded by the proposed one

The proposed solution supports also possibility to handle the configuration change event at run time, but this option is not tested and its implementation may change in new releases.

I hope the interface is ready to fulfill the following design time scenarios allowing for configuration in context of selected OPC Information Model/Address Space:

1. Plug-in to a modeler (UA Information Model design tool) as the configuration editor tool (preferred for me) - now it is compatible with the Address Space Model Designer

2. OPC UA Server as a local editor – using server local GUI, Address Space and the UANetworkingConfiguration plug-in (in this case OPC UA server is just modeler)

3. OPC UA Client as an editor - using client local GUI/UANetworkingConfiguration on the client-side, and remote access to the Address Space

4. OPC UA Server as a remote editor – using custom configuration Information Model/UANetworkingConfiguration plug-in on the server-side, and generic configuration OPC UA Client as the remote configuration tool,

5. OPC UA Server as a remote dedicated editor – using PubSub Information Model/UANetworkingConfiguration plug-in on the server-side, and dedicated (configuration editor GUI) PubSub configuration OPC UA Client as the remote configuration tool (let me stress it is the only scenario using PubSub Information Model) – it is rather run time approach.

It is my opinion, but options 4 and 5 are only theoretically possible because in real installations OPC server is an untouchable artifact, but in a lab, it is just Modeler and cannot be used as the run-time configuration tool.

It is a good opportunity to review your requirements (if you have any) against the proposed solution.

Configuration content

The detailed description of the configuration files content is captured in the code help documentation API Browser.

The XML schema of the configuration files is available at: ConfigurationData.xsd. Intentionally data producers and consumers use the same schema for configuration files. It makes it easier to harmonize these roles configuration and supports two roles in one application.

How to customize the configuration

By design it is a plug-in or using modern terminology application composition part of the library described in Reactive Networking (RxNetworking) of Semantic-Data Library and at run time it can be used as the primary source of configuration for any standalone OOI Reactive Application and UA Server supporting PubSub role.

In this case the application configuration may:

• be derived from the proposed one

• be expanded by the proposed one

The Configuration library provides the required serialization functionality. This functionality must not be cloned in the custom extension.

The proposed solution supports also possibility to handle the configuration change event at run time.

Custom class wrapping ConfigurationData

In this scenario, the custom class must implement IConfigurationDataFactory and contain a property with a public getter and setter of type ConfigurationData. The snippet below is an example illustrating this scenario. Complete code you may find in the Unit Test project.

[DataContractAttribute(Name = "ConfigurationDataWrapper", Namespace = Definitions.m_Namespace)]
[System.SerializableAttribute()]
[XmlRoot(Namespace = CommonDefinitions.Namespace)]
internal class ConfigurationDataWrapper : IConfigurationDataFactory
{

 ...
 [DataMember(EmitDefaultValue = false, IsRequired = true)]
 public ConfigurationData ConfigurationData { get; set; }
 ...

}

Custom class derived form ConfigurationData

In this scenario, the custom class is derived from ConfigurationData and may contain a vast variety of custom properties decorated with DataMemberAttribute to be serialized. The snippet below is an example illustrating this scenario. Complete code you may find in the Unit Test project.

[DataContractAttribute(Name = "CustomConfigurationData", Namespace = CommonDefinitions.Namespace)]
[SerializableAttribute()]
[XmlRoot(Namespace = CommonDefinitions.Namespace)]
public class CustomConfigurationData : ConfigurationData
{
 ...

 [DataMemberAttribute(EmitDefaultValue = true, IsRequired = true)]
 [XmlElementAttribute(IsNullable = false)]
 public string CustomProperty { get; set; }

 ...
}

Prerequisites

By design, the Configuration libraries depend on a logger functionality implementing the interface

UAOOI.Common.Infrastructure.Diagnostic.ITraceSource

defined in the UAOOI.Common.Infrastructure package. It is used to trace the behavior of libraries at run-time. To get an instance implementing this interface the CommonServiceLocator is used. The functionality required by the CommonServiceLocator has to be provided by the hosting application. Usually, it is provided by the composition container that is built at the application bootstrap stage. To get more visit this library home page Microsoft.Practices.ServiceLocation at GitHub.

If the CommonServiceLocator is not available a default logger (do nothing) is used.

See also

• Reactive Networking (RxNetworking) of Semantic-Data Library

• API Browser: the preliminary code help documentation is available for sponsors- consider joining

• Address Space Model Designer