Binding Doubts

[Mike Thomson]

What is the meaning og binding in terms of web service? What is the difference between HTTP, SOAP and MIME binding?

I have come across the word BINDING in many places in many articles and what is the real meaning of it.

[Peer Reynders]

In WSDL the interface is described in the abstract in WSDL 1.1 through the portType element and in WSDL 2.0 through the interface element. However the implementing service has to realize that interface. The type of binding determines how the interface is realized in the service. With an HTTP binding the interface is realized through a simple urlEncoded or urlReplacement HTTP GET or an HTTP POST request. With a SOAP binding the interface is realized with SOAP envelope - the SOAP binding itself declares which transport is used which in most cases is HTTP (transport="http://schemas.xmlsoap.org/soap/http"). With a MIME binding the interface is realized through a MIME envelope.

Things get a bit wobbly with SOAP with attachments (SwA) - the SOAP envelope is actually inside the first slot of a MIME envelope, the remaining slots in the MIME envelope carry the attachments.

WSDL 1.1:
SOAP Binding
HTTP GET & POST Binding
MIME Binding