wcf

The Technology:WCF technology supports the development of applications based on service-oriented architecture. Our implementation illustrates a stateful web service created with WCF. It also introduces the use of SOAP over Technology:HTTP. That necessitates the use of DTOs to wrap the domain model into leightweight serializable containers and pass it to the client.

Illustration

Technology:WCF uses contracts to generate Language:WSDL definitions for the web service. The contract is provided by a Language:CSharp interface. It contains all necessary methods for retreiving the company data and invoking the method cut on every entity within the company:

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The class

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is the concrete contract implementation. The implementation uses the basic Contribution:csharp for data generation and manipulation. Our contract class invokes the methods of the implementation and creates DTOs out of the retrieved entities. The example shows the implementation of the method

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. The method returns all necessary data for the company view encapsulated into a DTO:

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The DTO classes

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, and

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provide the serializability for view informations. The following example illustrates the DTO of the company, which contains fields for identifier, name, subdepartments and Feature:Total.

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Architecture

The base folder contains the contract definition this!!ICompanyService.cs and the contract implementation ComanyService.svc.cs. The file this!!CompanyService.svc links to the concrete implementation. DTO definitions are located in the dto folder. Both files, this!!clientaccesspolicy.xml and this!!crossdomain.xml, solve possible cross-domain issues. The .config files in the base folder are generated.

Usage

Requirements:

You need Microsoft Windows (preferably Vista or 7) running in combination with Technology:.NET 4.0.
Install Technology:IIS (Internet Information Services) 7 or 7.5 using the installation tutorials on IIS or MSDN. Make sure, that you have installed the "static content" feature as well.
Download the wcf implementation from github.

Build:

Use Technology:Visual Studio to build the project.

Create web site:

Go to the "Computer Management" dialog.
Open the "Services and Applications" root and select the "Internet Information Services (IIS) Manager".
On the right, there is a panel "Connections". Create a new web site by right click on "web sites".
Use wcf as "sitename" and link to the physical folder of the wcf implementation. Use port 1212.

Make sure that http://localhost:1212/CompanyService.svc shows that you have created a service. After the web service is running, continue with your client side application, for example Contribution:silverlight.

We also used:

version 4.0 of WCF
version 4.0 of Language:CSharp
and version 4.0 of the Technology:csc.exe compiler

to create the implementation.

Attention: When creating a service anywhere other than on the web server, that hosts your Silverlight application, cross-domain issues can arise. Cross-domain calls between Silverlight applications and services present a security vulnerability and must be specifically enabled by an appropriate cross-domain policy. For procedures that describe how to implement such a policy, see "Making a Service Available Across Domain Boundaries" <cite>MSDN2012CD</cite>.