Re: [Saxdotnet-devel] Requiring EndDocument

[Karl W. <ka...@wa...>]

> This is actually something that is already in place and only affects 
> implementations, but we need to clarify when we require EndDocument to
> be called.

Actually, what you sate below differes from what is currently documented:
The docs state:
<quote>
  To be more specific about when EndDocument() must be called: 
  It must always be called once StartDocument() has been called,
  even after a fatal error, unless IXmlReader.Parse() returned with an exception.
</quote>

 
> This is the proposal:
> 
> (a) EndDocument is required if StartDocument is called
> (b) Even when there is a FatalError
> (c) In the event of an encoding error, StartDocument should have been 
> called so EndDocument still needs to be called.
> (d) If there is an external exception (such as an IOExcpetion or a user 
> generated SaxExcpetion in a callback) EndDocument is still required.
> (e) EndDocument should be the final event in a SAX event stream.
> 
> Comments welcome,
> 

I agree with a, b, c and e.
About exceptions, whether user generated (call-back) or parser
generated (IO, AV due to parser bug), they should be a dead stop.
When the Parse() (or Resume()) method returned with an exception,
EndDocument should not have been called. Nor should there have been
any other call-backs after the exception.

If you throw an exception, you want everything to stop,
except for cleanup, which you should do right away in a finally
clause, until it is handled. That is how exceptions normally work.

If the parser throws the exception, only Parse()/Resume() can handle it,
if a call-back throws an exception (that is not handled by the
call-back itself), then who would reliably handle it? Again,
only Parse()/Resume(). You do not want any other functions, that
have nothing to do with exception handling or cleanup, called
in between.

Karl