DMU 2015 - 3. semester - oeadm15edD, oeadm15eiC

• you will have knowledge about what is a webservice
• you will be able to make a simple console/windows(wpf) client, witch can access a soap web service (asmx, WCF / svc) using the service reference and have knowledge for  how the classes can be generated from wsdl description (including DTO objects and proxy / service classes).
• you will be able to create simple web services using WCF service hosted in an ASP.NET application, including you are able to set up the service and data contracts
• you will be able to test your WCF services using WcfTestClient and by making your own small console / wpf test-clients.

Preparation: Read the materials written in the plan and grab on concepts (details for fotocopies - see fronter) - if you can manage to se the videos from previous lectures you might be ready for the exercises in classroom - you might have some question so prepare those at home.
As the video for demo ect. is only in danish, we will also have the speaks for intro and demo in classroom in english for international students and others that need it, but else you might work with the exercises nearby from the morning.
The exercises is supposed to be in an english version when we start the first lecturer.

Vi We will not walk through all the concepts, but only pick up where something is unclear and possible briefly discuss these.

Intro to webservice
- we will shortly talk about the concepts: RPC, RMI, Remoting, CORBA, MS old webservice (asmx)
- Protocols / formats
- WCF

If you want to have a little more speak about the concepts, you can watch this videos from previous (DK)
WebServiceIntro_20111117
(Note finally appear .NET 3.5, where we now must use .NET 4.0 if it is on our webhotel - see fronts) 

The Remote Facade pattern is also relevant in this context
- http://martinfowler.com/eaaCatalog/remoteFacade.html

Slides for the lecture:
Pp_WebServiceBegreber_ENG.ppt  - Samme på dansk 
Pp_WCF_Basic_Intro_ENG.ppt - Samme på dansk  

Extra readings (DK) from Digitaliseringsstyrelsen about IT-Arkitecture.
If you want to go deeper in the terms of SOA and Webservices in DK, you might find this link interesting - http://www.digst.dk/Arkitektur-og-data/It-arkitektur  
 

Video from teaching (previous session) for eventual repetition (DK)
  C# SDP14F uge11On WCF intro brug eksisterende i simpel klientprogram (ingen lyd)
Associated solution: 201403120912_KlientSolutionExterneService.zip

1) You might begin using the WcfTestClient.exe program to get data, witch can show the result directly.
The service contaons the following methods you might try out.
 - GetAllePersoner
 - GetAllePersonerMedNavn
 - GetAllePersonerMedPostnr
 - GetPersonMedPersonnr

2) Make a small client program in the same manner as shown in the demo, where you use the service methods to get data and display the data.
Be attention to Visual Studio will create a Person class based on the WCF service description in the WSDL, so you can by using the first 3 methods receive a collection of Person objects and from the last one a single Person object.

If you know how to use a collection in a WPF GridView you might use this to show the result easily. Remember to set the property AutoGenerateColumns tol true
You might also loop through the collection and write data on the console
 

• You will have knowledge how to make a statefull webservice by using WCF and ASP.NET Session (per user) & Application (common for all)
• You will be able to program webservices using WCF hosted in an ASP.NET web-application, including defining neded service and data contracts, besides ensure data survival in memory on server between calls (Statefullness) and thread safe for common data 
• You will have knowledge about about problems and possible solutions to offline concurrency (optimistic and pesimistic)
• You will have knowledge about using webservice to transaction scripting

Preparation:

• Take a second look on the literatur from last week and prepare som questions for outstanding elements
• Se highlight in plan below for more - danish videos is just an extra option, as they exist I have set them in the plan

Possibly. student(s) presentation of solutions for the exercies from last week
 

We will have a look on how to make data survive in memory (at server) in our WCF services
- For each client (PerSession / ASP.NET Session)
- For the applicationen - commont for all client (Single / ASP.NET Application) - be carefull!! thread safe
We will be concentrating on using ASP.NET Session/Application, and just se the choice of WCF Single/PerSession as orientation

Clientsiden - async:
We will also look at how we can make asynchronous calls from clients, so a user interface is not locked.
It may take time to complete a web service, and here it is appropriate to itself called incl. data transfer can be executed in a background thread, it's easy done with asynchronous calls.
- NB we take the solution with delegates and not Task

From previous year:
WcfServiceSolutionWithSimpleDTO_20140314.zip
WcfServiceSolutionWithSimpleDTO_UdvidetSessionAsync_201403171047.zip
Wpf_DataGrid_Template_i_XAML_201403171206.zip - example with template and databinding on DataGrid  

About Application state object: Application State
 

Slides: Pp_WCF_Async_Client_ENG.ppt - (Dansk udgave)

We will use ASP.NET Session, but if some you would like to hear comment how to uses WCF instanstypes (Single, PerSession and PerCall) - speak about slides on top
- C# SDP12E - WcfService - del2 (DK) 

If you are done you might eventual try to make a solution with the service with the same methods, but using a database instead of data is kept in memory.
 

Remember it is not the solution that is important, but that you have learned what you need and not at least get routine so you can do the job in a short time. This means sometimes you have to do the job all over again several times to get the training. ''

WCF Service continued
- follow up
- trådsikring (thread lock)
- offline lock - optimistic / pessimistic

Speak from previous year (DK):
C# SDP12E - Om pessimistisk / optimistisk ofline lock - problemstillingerne og løsningsmulighed 

• You get some knowledge of REST as an alternative to SOAP, including json as an alternative to XML for data transport
• You will be able to program simple Web services using .NET WebAPI
• You will be able to test simple web service (WebAPI) with direct use of HTTP request - concrete with Fidler and for GET with a browser
• Eventual - You will have some knowledge how to test your web service (WebAPI) using WebClient and based of using a simple WebApiRequest javascript template

Preparation:

Prepare yourself by watching the first part of the video below - what's going on and take some notes.
You must skip where he talks about html and other GUI for this time, as we only should work with services for now.
Concentrate about to make WebAPI and test them with Fiddler
Thursday, use the video to help you get started.
Introduction for WebApi - including something about om REST
- video tutorials ASP.NET Web API - Pluralsight (Jon Flanders)

Read briefly about WCF versus WebApi: https://msdn.microsoft.com/en-us/library/jj823172(v=vs.110).aspx

Tool for debuging af HTTP - should be used for testing WebApi - install before Thursday
Download Fiddler Web Debugging Tool for Free by Telerik 
 

Next tutorials might be a supplement if you need more
- video tutorials ASP.NET Web API - Getting Started , By Scott Hanselman (Channel9 - Microsoft)
- Getting Started with ASP.NET Web API 2 (C#):  https://www.asp.net/web-api/overview/getting-started-with-aspnet-web-api/tutorial-your-first-web-api
- eventual supplement explaning more about REST: Pluralsight REST Fundamentals
 

To reduce complexity of VS template for WebApi
Use this project as template for the exercises (not include all MVC)
WebApiSolution_BasicTemplate.zip

• You will be able to program simple Web services using .NET WebAPI and test them
• You will be able to use Routning and Action in your WebApi for controling the access
• You will be able to handle to return error-messages from a WebApi

Preparation:  

Prepare yourself by writing questions you need an answer of regarding WCF and WebApi primary based on the need to finish the exercises.
Prepare yourself on a presentation of your solutions of exercises (WCF and WebApi) - the state they must be in if not finish
Read about WebApi errorhandling se below.