All I know about acs-service-contract I just learned from google and
https://openacs.org/bboard/q-and-a-fetch-msg.tcl?msg_id=0002pn.
And I certainly don't want to delay openacs 4.
Differences I see between using acs-service-contract and using some piece of XML are:
- the XML contracts are probably slower. how much?
- the XML contracts can be fulfilled between any xml aware application. That might be
- two acs modules that might more efficiently use acs-service-contract, or
- it might be between any xml/soap/xml-rpc applications on the net, or
- the user aided by a point and clicky configuration widget
Search engines and ecommerce gateways are probably ideal examples of why and when to use acs-service-contract. Portal configuration by the user in a browser widget is the canonical example of when to use RSS or some XML to communicate. Perhaps site map querying is a good example for using both interfaces?