CDP4WspDal Overview

Introduction

The CDP4WspDal library is a C# library that provides an implementation of ECSS-E-TM-10-25A Annex C.2, the JSON REST API. The purpose of the CDP4WspDal is to communicate with any implementation of the ECSS-E-TM-10-25A Annex C.2. This includes the the CDP4-COMET Web Services and the ESA OCDT WSP. The JSON REST API is based on HTTP and makes use of GET and POST requests.

The ESA OCDT WSP is so-called ESA Community Software and is only available to organizations that reside in ESA member states.

The CDP4WspDal library is a very light weight library, it exposes only one class:

• CDP4WspDal: The class used to perform GET and POST requests on the CDP4-COMET Web Services. It implements the IDal interface and extends the abstract Dal super class.
• CDP4WspDal library does NOT support the COMET-Data-Model#ECSS-E-TM-10-25A-Annex-A-Extensions.

DalExport

The CDP4WspDal class is decorated with the DalExportAttribute. This allows it to be dynamicaly loaded using the Managed Extensibility Framework (MEF).

HttpClient

The CDP4WspDal is a wrapper around the the C# HttpClient. It takes care of all the nitty gritty details of the ECSS-E-TM-10-25A Annex C.2. It uses the Cdp4JsonSerializer to handle the deserialization of the DTO objects that are returned from the CDP4-COMET Web Services and the serialization of Classless DTO.

For each GET or POST request a Token is generated. This token is used to identify the request and responses that are being sent to the CDP4-COMET Web Services. The Token is used in NLog statements in order to be able to use these logs for debugging purposes.