[DUG] Web Services

[kurt]

Jeremy Coulter wrote:
>  It wont be so much the existing functions that will change, its more 
> that there will be new ones added.
> My question is, if/when a new function is added, how does the calling 
> exe know that its ok to call it? From what I have seen, when you add a 
> reference to a webservice, it creates a new PAS file that has all the 
> functions etc in it, and therefor this is compiled into the exe, so if I 
> add new functions one would assume that a new calling exe needs to be 
> updated....which is what I want to avoid.

Yup : well this is how its usually done in Java, dotNet & co.

Which strikes me (also) as defeating the point. There are others on the
list with better knowledge of dynamically dll's / bpl's than I, but
thats the approach I'd want to start with.

My own preference is to dodge the compile and write the thing yourself.
Its pretty straightforward to get a decent chunk out of the way using
MSXML: build up a string, send it, parse response.

You can run into tricky things, but it guarantees you can
  - talk to every service
  - add, remove, change services without recompile

And depends how much trouble you want to go to - if you don't need
a full-blown generic system, you may be better off with re-compiling.
For me: web-services are like crack, I want to use them everywhere
(explicitly declared interfaces? Hell yes).

Cheers, Kurt.