I am doing some research on web services. I have not written any web service but am doing a small write up on them. During my research I've come across terms contract-first and contract-last.
Can someone explain these two in an understandable form.
A:
Contract-first means you design the way your services are going to communicate with each other BEFORE your design the services themselves. Contract-last is the other way around -- you design how your service is going to work, then make one or more methods available as the interface for other services.
Kaleb Brasee
2009-12-14 05:15:18
+1
A:
To expound on the answer by Kaleb, contract-first is where you create the WSDL, and then you can create the implementation from this, and since the WSDL is your contract, this would be contract-first.
Contract-last is where the WSDL is created from the source code, or implementation, so it will most likely be generated by a tool rather than created by the developer.
Update
For a nice explanation with code, in Java, you can look at this explanation from the Spring 1.5 documentation.
http://static.springsource.org/spring-ws/sites/1.5/reference/html/why-contract-first.html
They will discuss the pros and cons, but they will be biased toward their approach, but, I think it is a nice explanation.
James Black
2009-12-14 07:39:13