Best Practices Server Side Scripting or Web Services

Question

Hello,

Let me start off by stating that I am a novice developer, so please excuse the elementary nature of my question(s).

I am currently working on a Flex Application, and am getting more and more confused about when to use server side scripting, and when to develop web services. For most of the functionality I am working on, I am taking various files from the user (client), uploading to the server for processing/conversion, then sending back to client in new format.

I am accomplishing most of this using asp.net generic handlers (ashx) files, but not very confident this is best practice. But at the same time, does making web services make any more sense? What would be considered best practice for this? Any suggestions would be greatly appreciated.

Answer 1

The way I look at it is as follows:

1. Web Services mean Established Best Practice.

For most of our development, we don't need to create "Web Services", or what I'm thinking when I think REST, SOAP, and the Twitter API. You only need to start doing that once you've got something you're going to be using every day for years.

1. Clean and DRY code will Lead you to Creating a Web Service

If you spend the time to clearly define the parts of your upload-process-render Architecture, and you find that it can be applied to almost everything you are doing, then all you need to do to make it a Web Service is define a clear, 1-2-3 set of rules for using the system (GET/POST data, etc.). As long as you are consciously building an architecture the whole way, you'll end up creating a Web Service if it's worthy. Otherwise there's no need.

It sounds like you have a clear workflow going, I don't know anything about asp.net though.

As far as it being confusing sometimes, and best practices, I suggest the following:

1. Create a Flex Library Project for your "generic ashx file handling" Flex classes. Give it a cool, simple name.
2. Create a .NET Library Project that encapsulates all the logic for your server-side file processing. Host it online and make it open source. I recommend github. Test it as you go, and document it, its purpose and the theory behind it.
3. If you don't have to do anymore work at this point, and it's just plug and chug, then you've probably arrived at something that might become a Web Service, though that's probably a few years down the road.

I don't think you should try to create a Web Service right off the bat. Just make some clean and reusable code, make a few examples, get it online and open source, have others contribute and give feedback, and if it solves a specific problem, then make it a web service. You can just use REST for now probably, and build your system around that. RestfulX is a great library for that.

Best, Lance

Answer 2

Hey making web services without any sense make no sense ;) Now in the world of FLEX as3 with flash version 10, you can easily read local files, modify them with whatever modifcation algorithm and save local files without pinging server. You only have to use webservices if you want to get some server data or to send some data to server. that's all.

RSTanvir

Answer 3

Flash / Flex uses a simple HTTP POST approach for file uploads, so trying to do that using SOAP web services will be problematic. Your approach of using ASHX here sounds reasonable to me.

To send / receive data that isn't file based (e.g. a list of files the user has uploaded previously), I would recommend looking at the open source Fluorine FX library. Fluorine uses AMF which is a highly performant way of doing data transfer with Flash. It's also purely configuration-based, which means you don't need to code against any of its APIs, just configure Fluorine to expose your .NET service classes. You could easily add attributes to those same classes to expose them as SOAP web services via WCF if you need that in the future. I would not recommend using SOAP with Flex however, due to the performance losses and also because the Flex implementation of SOAP has a history of bugs and interoperability problems.