[lxml-dev] schema validation - what would be valid at this point?

Mon Jun 30 22:22:44 CEST 2008

Display a list of approx. 3.40282e+38 possible codes and ask you to
select one.

:-)

I don't know what nxml-mode would do, it's RELAX-NG based and I don't
know if RELAX-NG supports patterns like that.

I guess there's no real need to support offering options for attribute
values (or text() node values), although nxml-mode will offer
"http://www.w3.org/1999/xhtml" as a value for @xmlns in <html>.

If it only generated lists of valid element names and attribute names
it would still be very helpful.

And like I said, I'm only suggesting that if the libxml2 schema API
exposes this it would be great if lxml could pass it on.  At some point
the validating parser must generate a list of valid element names in
order to check that the current element is in that list.  Granted
you've shown that for attribute values there may be no list, just a
match pattern, but I'm sure for element and attribute names there would
be a list.

Cheers -Terry

On Mon, 30 Jun 2008 13:02:34 -0700
"John Lovell" <jlovell at esd189.org> wrote:

> So with schema snippets that look like this, what would it give you as
> valid input options?
> 
> <xs:attribute name="RefId" use="required" type="sif:RefIdType" />
> 
>   <xs:simpleType name="RefIdType">
>     <xs:restriction base="sif:GUIDType" />
>   </xs:simpleType>
> 
>   <xs:simpleType name="GUIDType">
>     <xs:restriction>
>       <xs:simpleType>
>         <xs:restriction base="xs:token">
>           <xs:pattern value="[0-9A-F]{32}"
> xmlns:xs="http://www.w3.org/2001/XMLSchema" />
>         </xs:restriction>
>       </xs:simpleType>
>     </xs:restriction>
>   </xs:simpleType>
> 
> John W. Lovell
> Web Applications Engineer
> Northwest Educational Service District
> 1601 R Avenue
> Anacortes, WA 98221
> (360) 299-4086
> jlovell at nwesd.org
>  
> www.nwesd.org
> Together We Can ... 
> 
> -----Original Message-----
> From: Terry Brown [mailto:tbrown at nrri.umn.edu] 
> Sent: Monday, June 30, 2008 12:23 PM
> To: John Lovell
> Subject: Re: [lxml-dev] schema validation - what would be valid at
> this point?
> 
> On Mon, 30 Jun 2008 11:49:50 -0700
> "John Lovell" <jlovell at esd189.org> wrote:
> 
> > Can you give an example of what that might look like?
> 
> What I'd really like to have is the functionality of Emac's nxml-mode
> via a Python API.  That mode parses the text up to the insert point,
> and can then tell you what elements would be valid there, according
> to any RELAX-NX schema you specify.
> 
> So really I guess it makes more sense to be able to get the answer at
> parse time, rather than when the tree's complete.
> 
> If, so far, the parser has seen "<html><head>" the answer to the
> question "what's valid at this point?" would be "base, isindex, link,
> meta, script, style, title".  I don't know if the
> libxml2 schema API will answer that question, if not then it's more a
> libxml2 feature request (initally :) rather than an lxml thing.  Just
> using HTML as an example, you could answer in terms of any user
> supplied schema.
> 
> Sorry my initial description was confused because I was thinking about
> already complete and valid trees to which you might add something, it
> would be nice to handle that case too, but it seems to make more sense
> to approach it from the incomplete, half parsed :-) tree point of view
> first.
> 
> Cheers -Terry
>  
> 
> > John W. Lovell
> > Web Applications Engineer
> > Northwest Educational Service District
> > 1601 R Avenue
> > Anacortes, WA 98221
> > (360) 299-4086
> > jlovell at nwesd.org
> >  
> > www.nwesd.org
> > Together We Can ...
> > 
> > 
> > -----Original Message-----
> > From: lxml-dev-bounces at codespeak.net
> > [mailto:lxml-dev-bounces at codespeak.net] On Behalf Of Terry Brown
> > Sent: Monday, June 30, 2008 11:20 AM
> > To: lxml-dev at codespeak.net
> > Subject: [lxml-dev] schema validation - what would be valid at this 
> > point?
> > 
> > Hi all,
> > 
> > First thanks for lxml - it's great.
> > 
> > If this is the wrong place for feature requests please point me 
> > elsewhere...
> > 
> > A feature that would be very useful for a number of applications, 
> > particularly editors: the ability to ask "what attributes /
> > elements would be valid at this point?" where I guess a point would
> > be identified by an XPath or perhaps an Element object.
> > 
> > I don't know if any of the libxml2 schema APIs expose this, if they 
> > don't, that's probably where the change needs to be made first, but
> > if
> 
> > they do it would be great if lxml passed it on to python.
> > 
> > Thanks,
> > 
> > Terry
> > _______________________________________________
> > lxml-dev mailing list
> > lxml-dev at codespeak.net
> > http://codespeak.net/mailman/listinfo/lxml-dev
> > 
> 
> 
> 
> -----------------------------------------------------------------------
> Terry Brown               Natural Resources Research Institute
> Research Associate        5013 Miller Trunk Highway
> tbrown at nrri.umn.edu       University of Minnesota, Duluth
> Ph. 218 720 4345          Duluth, Minnesota 55811
> Fax 218 720 4328          http://beaver.nrri.umn.edu/~tbrown/
> _______________________________________________
> lxml-dev mailing list
> lxml-dev at codespeak.net
> http://codespeak.net/mailman/listinfo/lxml-dev
> 