[lxml-dev] About objectify

[David Soulayrol]

Le mercredi 23 janvier 2008 à 08:45 +0100, jholg at gmx.de a écrit :
> Hi,
>
> > - Why is the root element still an ObjectifiedElement instance ? It
> > seems to me I applied the same rules for both of my defined types.
> 
>  
> Now, objectify bases its element class lookup (i.e. which element
> class to use for the Python proxy representation) on certain rules:
>
> 1. if element has children => no data class
> 2. if element is defined as xsi:nil, return NoneElement class
> 3. check for Python type hint
> 4. check for XML Schema type hint
> 5. guess element class

Yes, it is in documentation which I should have read with more
attention. Sorry for that.


> # maps attribute values to element classes
> xsitype_class_mapping = {
>     "site": Configuration,
>     "title": MyString,
>     }
>  
> lookup = etree.AttributeBasedElementClassLookup(
>     "{http://www.w3.org/2001/XMLSchema-instance}type",
>     xsitype_class_mapping,
>     objectify.ObjectifyElementClassLookup())
>  
> parser = etree.XMLParser()
> parser.setElementClassLookup(lookup)
> objectify.setDefaultParser(parser)
>  
> root = objectify.fromstring("""
> <site xmlns:xsi='http://www.w3.org/2001/XMLSchema-instance'
>       xsi:type='site'>
>  
>   <title xsi:type='title'>Achille 2.0</title>
>   <value xsi:type='long'>2</value>
> </site>
> """)
>  
> print objectify.dump(root) 

This makes sense now.


> > - Is there a way to specify the xsi:type in a schema sheet ? This
> > question may sound stupid, but I'm still learning the XSD spec, and
> > I wonder if objectify could rely entirely on the schema, without the
> > need to add anything in the XML document itself.

> For now, there is nothing like a "typifier" that takes an instance and
> a schema and adds type information from the schema to the instance
> document.

Thanks for all the help.
--
David