Which type of creation of web-services is your primary choice?

Question

"Bottom up" or "top down"?

First I used top down but I felt to much design options that didn't have any implementation or validation.

Now my approach is "bottom up" heaven when a create a new service.

• Bottom-up: when you use the code to make the web-service.
• Top-Down: when you create and use the wsdl file to make the web-service and generate some code.

Answer 1

I'm not sure that you can describe wsdl creation as top-down vs. bottom-up. I think it just depends on what tools you're using. Some products lend themselves better to schema creation first. Others are better in starting with code. It really depends on what you have access to.

I think you may be able to describe an overall SOA implementation strategy as top-down vs. bottom-up. Bottom up is start building services at the data access level and then higher order services on top of those. Where top-down is get a major project, create a few services that are to be leveraged, scrub, rinse & repeat.

In this case, bottom up is the way to go. The ROI is longer, but it is because those services continue to be leveraged that you experience the savings soa purports to enable.

Answer 2

I use "contract first" - start with a schema describing the XML messages and work out from there. Generate the WSDL from that, and have the endpoints deal with XML. You can do "duck typing" that way.

Answer 3

I definitely prefer generating the WSDL from code, because modeling code-first is so much more comfortable and easy. Also, classes generated from an XSD tend to be rather messy in my experience, and can be a real nightmare when exposed as an API.