Re: [xml-dev] processing instruction with 'xml' target

[<juanrgonzaleza@canonicalscience.com>]

Chris Burdess said:
> <juanrgonzaleza@canonicalscience.com> wrote:
>> I am not sure if when I write <?xml version="1.0"?> in a doc I am
>> writing
>> a xml declaration or a PI.
>
> If you write it at the start of an XML document it is an XML
> declaration.
>
> If you write it anywhere else it is a well-formedness error,
> including at the start of an external entity since text declarations
> must supply an encoding attribute.

No exactly. According to the spec a <?xml version="1.0"?> at the start is
the XML declaration. According to certain parsers it is *not*. If i am
working with the formal spec ro with a correct implementation of the spec
it is not a PI. If i am working with a wrong implementation from an
incompetent (in own words of Mike here) then it can be a PI. I find more
cool the pragmatic attitude of Kurt Cagle, David Hunter and others when
saying:

<quote>
Actually, no: the XML declaration isn't a PI <they refer here to the
formal spec/>. But in most cases it really doesn't make any difference
whether it is or not, so feel free to look at it as one if you wish.
</quote>

or

<quote>
Trying to get the text of the XML declaration from an XML parser. Some
parsers erroneously treat the XML declaration as a PI, and will pass it on
as if it were, but many will not.
</quote>

I simply remarked that the dogma "the XML declaration is not a PI" can
fail in everyday practice. When i wrote <?xml version="1.0"?> in a doc it
can be a PI for parser W and can be not a PI for parser C.

>> The reply to above question depends of the arbiter used, the formal
>> spec
>> or a real working implementation?
>>
>> Apparently my Mozilla based browser sometimes deals the xml
>> declaration as
>> a PI. I obtain something like
>>
>> <message>
>> xml processing instruction not at start of external entity
>> </message>
>>
>> ... Sorry to say this but I never work with the formal
>> spec, just with real implementations in browsers, tools...
>
> Mozilla error messages are not normative. And just because many
> native English speakers say things like "If I was rich" doesn't make
> such utterances grammatically correct English.

The fact that Mozilla people call it pseudo-pi in technical documentation
(e.g. Doctype sniffing) suggest me that _sometimes_ they may be treating
the XML declaration as a PI of a special class.

> --
> 犬 Chris Burdess
>    "They that can give up essential liberty to obtain a little safety
> deserve neither liberty nor safety." - Benjamin Franklin


Juan R.

Center for CANONICAL |SCIENCE)