SOAP, Web Service Interaction using Flex 2

Question

A Web Service exists on the local computer. It is a .NET
Framework web service (SOAP) running under IIS. It commences with a
demand for three parameters. One fills in the form and presses a
button on the form and is returned an XML file with vital data
necessary for future web service transactions that will involve
SQL-form queries and XML responses. Actions that Flex 2 is required
to perform: 1) submit a URI and receive a form, 2) POST a response
to the form and receive an XML file, 3) submit a query, 4) reformat
an XML file to remove irrelevant data and to make a Flex 2 data
provider happy so that a chart can be displayed. I assume Flex 2
can do all these things and it is just a matter of knowing how.

Answer 1

Your description is a bit confusing. The webservice in
question has a single method that takes three parameters, and
returns a FORM? What are the three parameters, and what, exactly,
do you mean by "form".
When I hear "form", I usually think of an HTML form with text
input fields, comboboxes, radio buttons, etc. But, in general,
properly developed webservices do not return UI elements (such as
text input fields, comboboxes, and radio buttons). They are
typically only used as a communication method in the model layer,
where they return datasets or process responses. And the view layer
(in this case, Flex) is responsible for building any UI elements
that collect data for the interaction with the webservice.
But, okay, let's say, for some odd reason, this webservice
returns a form (as I am thinking of the term). What format is this
form in? I personally can't think of a readily available method
that could display this form with a Flex app, but maybe I'm missing
something. Or is it that, by "form", you mean something completely
different, like a second method in the webservice that receives
posted data? What is actually returned in your step #1?
Step #2 is a cinch. Simply create an HTTPService tag (or in
script, create URLLoader and URLRequest objects) in your app that
posts the appropriate data to the appropriate webservice URL with
the appropriate method. In the callback handler function for that
webservice call, a (properly formatted) XML response will be
converted automatically to a "Flex-friendly" data object, which you
can easily parse apart to build your SQL as necessary.
Step #3, again, where do you submit the query to? A third
method in the webservice? If so, it would be just like #2 above.
And the response data would, again, be automatically converted into
a Flex data object.
Step #4 would probably be accomplished more by manipulating
the Flex data object rather than any reformatting of the XML.
Simply loop through the object and remove irrelevant children/data.
Then set a bindable variable to the cleaned data object, and have
your chart bound to that variable.
There are many many examples on the web. Just search for
'flex "mx:HTTPService"' or similar. And take a look through
LiveDocs for [Bindable] for step #4.