Re: XMLP/SOAP spec - processing instructions

Hello Randy,

>The XMPL/SOAP spec (as well as the SOAP 1.1 spec) specifically
>prohibits XML processing instructions (sec 3, para 4). I take
>this to mean that the XML prolog (<?xml ... ?>)is prohibited.
No.
According to syntax production 22 and 23 of XML v1.0 2nd edition the XML 
declaration isn't a processing instruction.
PIs are governed by production 16. They are explicitly allowed solely within 
misc (27) and markup declaration (43) but not as child of document (production 
1). 
Therefore the XML prolog cannot be a processing instruction.
Historically, it is a processing instruction but only in terms of SGML telling 
a SGML aware processor to process the content after the PI as XML.

>2. Can we relax this prohibition in our spec and allow an
>XML prolog? As long as it is optional I don't think it would
>break any existing applications.
I don't think we should relax this part of SOAP since PIs can really considered 
harmful ...
But the XML prolog should be allowed within a SOAP/XMLP message since the 
encoding declaration is necessary when using other encodings than UTF-8 or 
UTF-16. (see appendix F.1 of XML spec.)

Cheers,
Mario

Received on Tuesday, 22 May 2001 11:13:26 UTC