Feeds

Consume .NET services without Silverlight

Adobe Flex comes through

Providing a secure and efficient Helpdesk

Web bling tone Can Adobe Systems' Flex access Microsoft .NET web services? Adobe tends to promote its own ColdFusion or LiveCycle Data Services for use with Flex, but it also has support for SOAP 1.1.

When Microsoft released Silverlight 2 second beta last month, I tested it by building a simple Create, Retrieve, Update, Delete (CRUD) database application, following all the defaults: SQL Server, ASP.NET, Windows Communication Foundation (WCF) web service, and of course Visual Studio 2008 to bring it all together. It wasn't entirely painless, but the problems were largely in getting Microsoft's beta tools to install correctly; in the end it worked well.

I could not resist trying Flex with the same web service. Since I had used the BasicHttpBinding for the WCF service, it should be compatible. How easy would it be? It is a key point for developers on Microsoft's platform who may be eyeing Flex or AIR with interest.

I installed my web service into IIS 7.0 and tested it. It is a simple affair, designed to be the back end for a rudimentary guestbook. There is a GuestItem class, which represents an entry in the book, and a web service with three methods: GetGuestEntries, SaveGuestItem and DeleteGuestItem. I fired up FlexBuilder, created a new Flex web application project, and added a DataGrid and a few other controls that I hoped to populate with my data. Then I chose Import Web Service from the Data menu.

Import WSDL screen grab

Microsoft's web service is sucked into FlexBuilder

FlexBuilder proceeded to generate nearly forty ActionScript files in order to wrap the service. Still, I was in luck: the import worked. Adobe is actually using a modified version of the excellent Apache Axis2, which is encouraging.

The next question was how to talk to the service. I opened GuestBook.as, and was delighted to find comments with code samples, even though they were not quite complete. The basic pattern is this:

1. Create an instance of the web service wrapper class

2. Add a listener that corresponds to the method you will call. The web service is called asynchronously, and the function you supply for the listener will be called when the result is received

3. Add a listener for SOAP faults. This is a kind of exception handler

4. Call the service method

Fortunately these steps only take a few lines of code. Here is the listener function, which binds the list of entries to the DataGrid:


  public function getGuestItemsResult(e:GetGuestItemsResultEvent):void {
        grdGuestBook.dataProvider = e.result;
  }

Here is the code which calls the web service:


   public function refreshGuestList():void {
   var guestService:GuestBook= new GuestBook();
   guestService.addgetGuestItemsEventListener(getGuestItemsResult);
   guestService.addGuestBookFaultEventListener(getFaultResult);
   guestService.getGuestItems();        
   }


Incidentally, the C# method that implements the service looks like this:


[OperationContract]
public List<GuestItem> GetGuestItems()

The ActionScript wrapper represents this as a custom class, ArrayOfGuestItem, which extends ArrayCollection, and this binds nicely to a DataGrid. I just needed to set the dataField attribute of each column in the grid to match the properties of a GuestItem.

Internet Security Threat Report 2014

More from The Register

next story
UNIX greybeards threaten Debian fork over systemd plan
'Veteran Unix Admins' fear desktop emphasis is betraying open source
Netscape Navigator - the browser that started it all - turns 20
It was 20 years ago today, Marc Andreeesen taught the band to play
Redmond top man Satya Nadella: 'Microsoft LOVES Linux'
Open-source 'love' fairly runneth over at cloud event
Chrome 38's new HTML tag support makes fatties FIT and SKINNIER
First browser to protect networks' bandwith using official spec
Admins! Never mind POODLE, there're NEW OpenSSL bugs to splat
Four new patches for open-source crypto libraries
prev story

Whitepapers

Forging a new future with identity relationship management
Learn about ForgeRock's next generation IRM platform and how it is designed to empower CEOS's and enterprises to engage with consumers.
Why and how to choose the right cloud vendor
The benefits of cloud-based storage in your processes. Eliminate onsite, disk-based backup and archiving in favor of cloud-based data protection.
Three 1TB solid state scorchers up for grabs
Big SSDs can be expensive but think big and think free because you could be the lucky winner of one of three 1TB Samsung SSD 840 EVO drives that we’re giving away worth over £300 apiece.
Reg Reader Research: SaaS based Email and Office Productivity Tools
Read this Reg reader report which provides advice and guidance for SMBs towards the use of SaaS based email and Office productivity tools.
Security for virtualized datacentres
Legacy security solutions are inefficient due to the architectural differences between physical and virtual environments.