WSDL and SOAP

[jinduy]

I've often come across these two terms at work and haven't bothered to ask there, so I'll ask here (b/c atot is smarter).

From my basic understanding in a nutshell:

WSDL - provides XML specification of the structure of incoming requests for a service provider or component

SOAP - just a fancy name for sending xml requests over http


What is mind boggling to me is that WSDL and SOAP should be given one umbrella name because they're always going to go together.... WSDL expects an xml format and SOAP sends and receives certain XML format... what am i missing here?

why can't they give it one umbrella name like "web service standard" or something?

 

[NiKeFiDO]

They don't actually necessarily need to go together.

In fact, I'm working with SOAP web service right now that does not use WSDL (and it's a huge pain in the ass).

SOAP is the protocol which wraps XML and sends it off, while WSDL makes using a SOAP web service easier by "describing it".

For instance (I'm a PHP developer, so my example uses that), check this link out to see the difference between using a web service with and without WSDL with PHP:

http://devzone.zend.com/node/view/id/689

The first code example shows a SOAP call without WSDL. The second example shows it with WSDL. See how much easier WSDL makes getting data from a web service?

Hope this helps clarify it for you.

 

[JasonCoder]

They are both just XML dialects. One does "description of a service" while the other does the service itself. Why can't it all just be the same thing? Well I guess it could but it isn't. Description didn't make it into the SOAP spec AFAIK.

SOAP is getting a bad rap nowadays as everyone seems to be in love with REST.

 

[Markbnj]

SOAP is just so damn verbose, but as network speeds keep increasing I think we'll bias towards completeness and away from terseness. I'll take json over REST right now, but I'll use SOAP if it makes sense.

 

[EagleKeeper]

SOAP also came much earlier than WCF.

We were using SOAP on a project in '04 between slots systems and the back end servers.