Appendix I. NEsper .NET -Specific Information

Java Class	Description
`System.Object`	Any .NET object with properties.
`System.Collections.Generic.IDictionary`	Map events are implementations of the `IDictionary` interface where each map entry is a propery value.
`System.Array, System.Object[] (array of object)`	Object-array events are arrays of objects (type `Object[]`) where each array element is a property value.
`System.Xml.XmlNode` and `System.Xml.Linq.XNode`	XML document object model (DOM).
Application classes	Plug-in event representation via the extension API.

I.7. .NET Object Events

Event classes provide accessors (getter methods) and mutators (setter methods) by means of auto-implemented properties or read write properties.

Below an example using auto-implemented properties:

class NewEmployeeEvent {
  public string FirstName { get; set; }
  public Address Address { get; set; }	
}

Below an example using read write properties:

class NewEmployeeEvent {
  private string firstName = "N/A";
  private Address address = 0;

  public string FirstName
  {
    get
    {
      return firstName;
    }
    set
    {
      firstName = value;
    }
  }

  public Address Address
  {
    get
    {
      return address;
    }
    set
    {
      address = value;
    }
  }
}

The case conversion is uppercase as dictated by .NET property conventions.

Mapped indexes are handled through the indexing operator.

I.8. .NET IDictionary Events

For .NET the events can be represented by objects that implement the IDictionary interface.

I.9. .NET XML Events

XML events are represented by System.Xml and System.Xml.Linq.

I.10. .NET Event Objects Instantiated and Populated by `Insert Into`

Objects need to follow the .NET property conventions. Objects can follow modified conventions for Java-style accessors and mutators using Get and Set respectively.

I.11. .NET Basic Concepts

There are no differences between Esper and NEsper in respect to basic concepts.

I.12. .NET EPL Syntax - Data Types

The data types are sbyte, byte, short, ushort, int, uint, long, ulong, float, double, decimal.

I.13. .NET Accessing Relational Data via SQL

.NET uses ADO-based drivers to accomplish the same work.

I.14. .NET API - Receiving Statement Results

NEsper exposes the Events events on EPStatement objects.

UpdateListener is replaced by UpdateEventHandler in .NET. Subscriber objects must implement the Update method or subscriber objects must be a delegate with an appropriate number of arguments.

The setSubscriber method is replaced with the Subscriber property. This property can take an object or a delegate.

Iterator is replaced with GetEnumerator. SafeIterator is replaced with GetSafeEnumerator.

In NEsper you can assign a delegate to a subscriber using lamba this way:

statement.Subscriber = new Action<TradeReportEvent, NesperTest>((a, b) => {
  Debug.Print("got here");
});

I.15. .NET API - Adding Listeners

Listeners are replaced with UpdateEventHandlers, for example countStatement.Events += (sender, args) => { DoWork(); }.

I.16. .NET API - Runtime Threading and Concurrency

When using internal timer (and not the application provided external time), please note:

Windows uses a high resolution timer that uses the windows multimedia timers with a resolution of 1 millisecond. High resolution timers are cleaned up when the AppDomain is disposed.
If using Mono, Mono uses an internal timer that attempts to account for clock skew and drift.

I.17. .NET Configurations - Relational Database Access

Connections are obtained by selecting a DbDriver, which are a NEsper-construct.

DbDriverGeneric: Positional or name based driver that must be completely configured prior to use.
DbDriverMySQL: Positional based driver that uses '?' prefix.
DbDriverODBC: Positional based driver that uses '?' prefix.
DbDriverSqlServer: Translates positional into named-based SqlParameters with '@' prefix.

I.18. .NET Configurations - Logging Configuration

Log4j is replaced by .NET Commons Logging.