Hi Ian, I'm using XML over HTTPService in my current app and may be able to help with some of this. Responses inline below.
--- In flexcoders@yahoogroups.com, Ian Shafer <[EMAIL PROTECTED]> wrote: > ...regarding using HTTPService: > > * Should I be using it? I'm choosing to use HTTPService because I don't > want to pay for FDS and it (HTTPService) *seems* simple so that if there > are problems, I could easily be able to fix them (as opposed to using > FDS and Adobe's proprietary encoding). Also, XML over HTTP is simple and > always works. Hooking up remote objects just seems like a pain. The answer to that question ultimately comes down to your specific project needs, of course. I'm not using FDS (for the usual reasons), and there doesn't appear to be an open-source (or otherwise really cheap) alternative to using AMF3 to communicate to a Java backend. So that really leaves some flavor of XML over HTTP as the raw message language and protocol. We deliberated between SOAP, REST and homegrown XML message protocols, and ultimately settled on homegrown for a variety of reasons I won't bore you with. Again, it really depends on your specific needs, but so far our solution is shaping up very nicely. > * What is the best resultFormat to use. As far as I can tell, there are > three: object, e4x, and xml. The xml format seems obsolete since we now > have e4x. Is there any reason to use xml? I get e4x (pretty sweet, I > think this is a *great* language feature). The only drawback I've found > so far is the datatype of e4x values. They all seem to be Strings. I get > this, but I wonder if there's an easy way to say "all @quantity fields > are numeric" so it'll sort nice in a DataGrid. object seems cool, but > I'm not 100% clear how it works. Me neither, frankly. I might consider trying it, though, given that there is apparently some basic type casting done when you use this format, according to the dev guide: "By default, the resultFormat property value of HTTPService components and WebService component operations is object, and the data that is returned is represented as a simple tree of ActionScript objects. Flex interprets the XML data that a web service or HTTP service returns to appropriately represent base types, such as String, Number, Boolean, and Date. To work with strongly typed objects, you must populate those objects using the object tree that Flex creates." > Can I tell HTTPService which class to > bind the objects to? I don't use Flex Builder (again, I don't like to > pay for software, and I don't have the money), so it's tough to > introspect the objects at runtime (although I did see something about > command line debugging, I'll have to look into that). I believe this creates a new graph of objects with dynamically created properties. I don't believe there's any configurable mechanism for mapping XML to particular object classes or types; I think if you need mapping different from what resultFormat="object" gives you, you need to roll your own. Not positive, though. > * I want to call (HTTPService.send()) my service with different query > parameters. What's the best way to do this? Currently, I'm creating a > new HTTPService in AS and generating the URL every time it is called. > This doesn't seem right to me. Nah, it ain't :) Create a single HTTPService and modify its request property; this property takes "an object of name/value pairs", which just means that it'll treat every property name on the object as a parameter name and will call toString() on the property value to get the parameter value. You may want to look at Cairngorm's implementation of the Service Locator pattern, which provides an application-wide singleton that wraps you services, allowing central definition of services along with global access to them. I like the pattern, your mileage may vary. > * Should I use a service-config.xml file? I haven't been able to find > good documentation on this? Only applies to FDS, I'm pretty sure.
