bugs? [was: Re: success stories with xml.apache.org]

[Mike Pogue <mp...@apache.org>]

Honestly, to my knowledge, nobody has reported any of these bugs before, at least
on Xerces.  Some of these bugs are clearly on Xalan, too.

See below for additional questions!

Mike

"HERRICK, CHUCK (SBCSI)" wrote:
> 
> regarding:
> --
> Resetting the parser causes the document it last generated to become
> corrupt.
> --
> I would imagine this would be fairly mission critical.
> Is there somewhere where we can find out if this bug
> is being addressed and by whom? That way trying to
> work toward a fix wouldn't collide with a parallel
> effort.
>

http://xml.apache.org/bugs is the new bug tracking system.  We're just getting
started to enter bugs in there.  But, this one isn't there (assuming it's a 
Xerces bug).  And, to my knowledge, nobody has ever reported anything like this.

 
> -----Original Message-----
> From: Eric Hodges [mailto:harmony2@swbell.net]
> Sent: Tuesday, February 29, 2000 5:47 PM
> To: general@xml.apache.org
> Subject: Re: success stories with xml.apache.org
> 
> Why did we switch:  because OpenXML said they merged into Apache and OpenXQL
> disappeared.  Also we want to support the XPath standard.
> 
> Our experience with Xalan and Xerces:
> Negative:
>     Some of the source code won't build on JDK 1.2.2.

Xerces is compiled routinely with 1.2.2.  Can you provide more details
(to the Xerces board)?


>     Some simple XPaths caused exceptions to be thrown.
>     Resetting the parser causes the document it last generated to become
> corrupt.

Do you have a test case that demonstrates this?


>     Still having a hard time figuring out which method to call, in what
> order, and what arguments they expect.
>     Very little documentation on the API.

Are these Xerces or Xalan comments?

> Positive:
>     Some good responses from the mailing list and people working on these
> products.
>     Supports the XPath standard.
> 
> In general, I'm getting the gut feeling that these things work when plugged
> into Apache, but the APIs haven't been exercised by many other applications.
> A lot of the information about how to use these APIs must be encoded in
> Apache.  It would be nice if some helper classes could provide common usage
> patterns with a simplified API.
> 
> For instance, to execute an XPath, Xalan requires this code:
> 
>         XPathSupportDefault xpath_support = new XPathSupportDefault();
>         XPath xpath = new XPath(xpath_support,null);
>         XPathProcessorImpl parser = new XPathProcessorImpl(xpath_support);
>         xpath.installFunction("document", new
> org.apache.xalan.xslt.FuncDocument());
>         parser.initXPath(xpath, queryString,null);
>         XObject xobject = xpath.execute(xpath_support,document,null);
> 
> while XPathDOM (another OpenSource XPath implementation) requires this code:
> 
>         Evaluator ev = new Evaluator(doc);
>         Object obj = ev.eval(queryString);
> 
> In the Xalan code, it's hard to find out what an XPathSupportDefault is, or
> why XPath requires one to call installFunction() before using it.  Without
> help from the mailing list, I'd have never figured some of this stuff out.
> 
> I don't want to make anyone angry by complaining, just want to give an
> outsider's perspective.  I'm glad this code is out there and I hope it
> becomes more robust and easier to use.  Hats off to all those folks that
> contribute to it.
> 
> ----- Original Message -----
> From: Brian Behlendorf <br...@apache.org>
> To: <ge...@xml.apache.org>
> Sent: Tuesday, February 29, 2000 6:55 AM
> Subject: success stories with xml.apache.org
> 
> >
> > So in ~8 hours I'll be giving a short keynote at XTech in San Jose on
> > Apache, and focus however much I can on XML and the xml.apache.org
> > project.  I follow general@xml fairly closely but I've been unsubscribed
> > from the main development lists; so if there are developments or
> > noteworthy things you'd like to let others know about, let me know.  I'm
> > also very interested in hearing about people who were formerly using
> > someone else's XML parser or stylesheet engine or (anything else) and
> > switched to something created at xml.apache.org, and why.  Or any other
> > random data points you think might be noteworthy.  If anyone would like to
> > contribute some, email me or the list.  Thanks!
> >
> > Brian
> >
> >
> >

Re: bugs? [was: Re: success stories with xml.apache.org]

[Eric Hodges <ha...@swbell.net>]

----- Original Message -----
From: "Mike Pogue" <mp...@apache.org>
To: <ge...@xml.apache.org>
Sent: Wednesday, March 01, 2000 11:17 AM
Subject: bugs? [was: Re: success stories with xml.apache.org]


> Honestly, to my knowledge, nobody has reported any of these bugs before,
at least
> on Xerces.  Some of these bugs are clearly on Xalan, too.
>
> See below for additional questions!
>
> Mike
>
> "HERRICK, CHUCK (SBCSI)" wrote:
> >
> > regarding:
> > --
> > Resetting the parser causes the document it last generated to become
> > corrupt.
> > --
> > I would imagine this would be fairly mission critical.
> > Is there somewhere where we can find out if this bug
> > is being addressed and by whom? That way trying to
> > work toward a fix wouldn't collide with a parallel
> > effort.
> >
>
> http://xml.apache.org/bugs is the new bug tracking system.  We're just
getting
> started to enter bugs in there.  But, this one isn't there (assuming it's
a
> Xerces bug).  And, to my knowledge, nobody has ever reported anything like
this.

It's a problem with resetting the parser.  It seems to wipe out the DTM
string tables or something.  Once a document has been produced by the
parser, calling reset() screws up the document.  It was discussed on
comp.text.xml, I believe.  I was not aware of any formal mechanism for
reporting bugs.

>
>
> > -----Original Message-----
> > From: Eric Hodges [mailto:harmony2@swbell.net]
> > Sent: Tuesday, February 29, 2000 5:47 PM
> > To: general@xml.apache.org
> > Subject: Re: success stories with xml.apache.org
> >
> > Why did we switch:  because OpenXML said they merged into Apache and
OpenXQL
> > disappeared.  Also we want to support the XPath standard.
> >
> > Our experience with Xalan and Xerces:
> > Negative:
> >     Some of the source code won't build on JDK 1.2.2.
>
> Xerces is compiled routinely with 1.2.2.  Can you provide more details
> (to the Xerces board)?

These problems were in Xalan.  Specifically, static members were referenced
from instance variables, not from the class.

>
>
> >     Some simple XPaths caused exceptions to be thrown.
> >     Resetting the parser causes the document it last generated to become
> > corrupt.
>
> Do you have a test case that demonstrates this?

I haven't written a test case, but I can reproduce the behavior.  Removing
the call to reset() and creating a new parser for each parse solves the
problem.

>
>
> >     Still having a hard time figuring out which method to call, in what
> > order, and what arguments they expect.
> >     Very little documentation on the API.
>
> Are these Xerces or Xalan comments?

Both.  The Javadoc comments fail to explain the purpose of most of the
arguments, or they are expressed in terms unfamiliar to me.  And the calling
sequence is extremely comlicated and non intuitive for simple operations
like parsing and executing XPaths.