How to Retrieve Data From Web Service with Optional Arguments

Question

This should be a simple one. I have a web service that
returns a list of books. There are 3 optional arguments that can be
passed to this (ex. book type, author, id) to filter this list. Do
I still need to use the <mx:request> tags if I am not going
to pass any parameters to the web service?
When I look at the services browser in Flex, it says "unable
to get meta data for CFC". However, if I remove the arguments from
the CFC and then call the service again, all my data now appears.
What's the best way to appoach this?
Thanks in advance

Answer 1

I have a similar application. What I have done is create one
argument in my CFC, with a type of "struct". Then, in the Flex
Application, I create an Object (Associative Array), and pass this
to the CFC as that one argument.
Here is the ActionScript:
// Create the variable to be passed to the WebService
[Bindable]
private var object:Object = new Object();
Then in another function, you create the Object, based on
specified values - perhaps from ComboBox selections:
object.bookType = comboBox1.selectedItem["bookType"];
object.author = comboBox2.selectedItem["author"];
object.id = comboBox3.selectedItem["id"];
Then you pass that one argument in your <mx:request>:
<mx:WebService id="getBooks" wsdl"
http://server.com/service.wsdl"
showBusyCursor="true"
fault="alert(event.fault.faultstring)">
<mx:operation name="sBooks">
<mx:request>
<args>{object}</args>
</mx:request>
</mx:operation>
</mx:WebService>
Your CFC might look like this:
<cfcomponent>
<cffunction method="sBooks">
<cfargument name="args" type="struct">
</cffunction>
</cfcomponent>
Then you can worry about validating the values passed to the
CFC in the CFC function. That way, you could send an empty struct
if you wanted, and the CFC would not throw an exception.
Hope that helps.