Re: [udig-devel] Plea to avoid workarounds for broken servers

[dzwiers@xxxxxxxxxxxxxxx]

James:

As far as WFS goes ... it's all over the command line (just ask jesse), but was
planning to more it to a logger. WMS currently has it's order validation turned
off ... this means that elements are dealt with as if they were a set rather
than a list. The parser also ignores dtd extension where the specififcation
allows them to do so. 

I am not aware of any other changes. Perhaps a DS param for SPEED would be good
in these cases (option to do full validation of the element order and existance).

David

Quoting James Macgill <jmacgill@xxxxxxxxx>:

> I know its a very hard decision to make and it is hard to be the group
> that makes a stand, but I would hate to see the WMS and WFS specs
> going the way of HTML.
> 
> The major players Netscape and IE were so forgiving with html markup
> that it almost stopped being a standard and novice page writers and
> tool developers thought they were writing valid code because it always
> seemed to work.  (<b><i>bold italic</b></i> anyone?)
> 
> The seperation makes some sense, though it might well lead to a fork
> of the data store modules.  How, for example, would you work around a
> broken 1.3.0 WMS that was using x and y instead of i and j for pixel
> coordinates without modifying the code in geotools?
> 
> I feel that the workarounds would make the code harder to maintain and
> would further remove pressure on server developers to fix their code.
> 
> That said, I can appricate that limiting what a user can do is not
> something you may want to contemplate, in which case can I at least
> ask for a strong error warning box so that the user knows they are
> working with a broken server.
> 
> James
> 
> On Mon, 17 Jan 2005 11:19:31 -0800, Richard Gould
> <rgould@xxxxxxxxxxxxxxx> wrote:
> > Hi James,
> >
> > >I'd just like to make a plea that no-one adds workarounds for broken
> > >servers into the codebase, (I have no indication that anyone has done
> > >this yet, but I just want to be sure no-one is even slightly tempted!)
> > >
> > >
> > Too late. David's XML implementation allows quite a large amount of
> > flexibility on the parsing end, allowing quite a few misbehaving servers
> > to be read properly. I have already added in some fixes that allow us to
> > parse non-standards compliant servers (and they are not hacks).
> >
> > >A broken server is just that, and any attempt to support or work round
> > >servers that are off spec will lead to a slow but painfull death for
> > >interoprability as a whole.  It is tempting to want to give the 'best
> > >user experience' by letting our users see the content of broken
> > >servers but if everyone did that we might as well not have standards.
> > >
> > >
> > My initial instinct is to disagree with you on this one, but I am
> > definately willing to heed your wisdom, as you definately have more
> > experience with this sort of thing compared to myself. It seems to me
> > that the value of being able to parse nearly every single server out
> > there is more than strictly enforcing the standards. If someone wants to
> > use the code to communicate with a specific server they have in mind,
> > they might be turned away if they find we cannot parse it. It is
> > probably less work on their behalf to find a client that *does* parse it
> > than contacting the administrator of the server and informing them of
> > their standards deviance.
> >
> > It also doesn't mix well with uDig's goals of as much interoperability
> > as possible. A possible fix for this would be to separate the WMS plugin
> > into a strictly standards compliant section (GeoTools) and a more
> > relaxed version (uDig).
> >
> > Richard
> >
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