Re: describing a service that returns an image/jpg (for example)

* Sanjiva Weerawarana <sanjiva@opensource.lk> [2005-10-13 22:47+0600]
> 
> Consider a service that takes a URI and returns a picture. 
> 
> Input message:
> 
> <element name="input">
>   <complexType>
>     <sequence>
>       <element name="id" type="xsd:string"/>
>     </sequence>
>   </complexType>
> </element>
> 
> Output message:
> 
> <element name="output">
>   <complexType>
>     <sequence>
>       <element name="image" type="xsd:base64"
>                xmime:expectedContentType="image/*"/>
>     </sequence>
>   </complexType>
> </element>
> 
> Operation:
> 
> <operation name="gimme-image"
>            style="style/iri style/one-binary-thing">
>   <input message="tns:input"/>
>   <output message="tns:output"/>
> </operation>
> 
> Note that the use of the style "style/iri" on /operation effectively
> constrains the input element. The addition of the style
> "style/one-binary-thing" constrains the output schema to be of the
> pattern above: exactly one child in the sequence and it must be declared
> as xsd:base64 along with the xmime:expectedContentType attribute.
> 
> And now the all important binding:
> 
> <binding name="foo" interface="..">
>   <operation name="gimme-image" whttp:operation="GET"
>         whttp:outputSerialization="image/jpg"/>
> </binding>
> 
> When we document the "one-binary-thing" style we say that that if that
> style is used then the output serialization must be set to something
> that conforms to the expected content type given in the schema.
> 
> This obviously needs to be spec'ized to become real, but is it really
> that simple?

That's a nice trick which I think works, and works well for binary
content. However, in LC337, the DAWG talks about HTML, plain text,
RDF. Won't they be forced to declare say their RDF as Base64-encoded?

  <element name="output">
    <complexType>
      <sequence>
	<element name="my-rdf" type="xsd:base64"
		 xmime:expectedContentType="application/rdf+xml"/>
      </sequence>
    </complexType>
  </element>

Cheers,

Hugo

-- 
Hugo Haas - W3C
mailto:hugo@w3.org - http://www.w3.org/People/Hugo/