"binding" - Binding Definition Element

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∟"binding" - Binding Definition Element

This section describes 'binding', a definition element that defines a binding for operations defined in an interface to a communication protocol and a message transmission format.

"binding" is a top level element of a WSDL 2.0 document. "binding" is used to define a binding with one or multiple given operations being bound to a communication protocol with extensibility elements from WSDL 2.0 extensions. The syntax of "binding" looks like this:

  <wsdl:binding name="nmtoken" interface="qname1" type="uri">
    ... extensibility elements from WSDL 2.0 extension ...
    <wsdl:fault ref="qname2">
      ... extensibility elements from WSDL 2.0 extension ...
    </wsdl:fault>
    <wsdl:operation ref="qname3">
      ... extensibility elements from WSDL 2.0 extension ...
      <wsdl:input messageLabel="In">
        ... extensibility elements from WSDL 2.0 extension ...
      </wsdl:input>
      <wsdl:output messageLabel="Out">
        ... extensibility elements from WSDL 2.0 extension ...
      </wsdl:output>
      <wsdl:infault ref="qname4" messageLabel="In">
        ... extensibility elements from WSDL 2.0 extension ...
      </wsdl:infault>
      <wsdl:outfault ref="qname4" messageLabel="Out">
        ... extensibility elements from WSDL 2.0 extension ...
      </wsdl:infault>
    </wsdl:operation>
  </wsdl:binding>

Notes on the "binding" element:

name="nmtoken" - Provides a reference name to this binding.
interface="qname1" - Specifies an interface by referring to an "interface" element.
type="uri" - Specifies a binding type.
ref="qname2" - Specifies a fault message defined in the interface.
ref="qname3" - Specifies an operation defined in the interface.
messageLabel="In|Out" - Specifies the message direction.
ref="qname4" - Specifies an infault/outfault defined in the interface.
Extensibility elements from WSDL 2.0 extensions are used to provide additional binding information at different levels.

Here is an example of "binding" element:

  <wsdl:binding name="helloBinding"
    interface="hy:helloInterface"
    type="http://www.w3.org/ns/wsdl/soap"
    wsoap:protocol="http://www.w3.org/2003/05/soap/bindings/HTTP/">
    <wsdl:operation ref="hy:Hello"
      wsoap:mep="http://www.w3.org/2003/05/soap/mep/soap-response"/>
  </wsdl:binding>

In this example,

Binding, helloBinding, is defined to bind operation, Hello, in interface, helloInterface.
This binding uses the WSDL SOAP extension to specify SOAP over HTTP as the communication protocol.
No binding provided for any fault message, because my operation has no "fault" defined.