Re: [xml] (correct) way to link external subset to newly crea ted XML doc

[Daniel Veillard <veillard redhat com>]

On Tue, Jan 08, 2002 at 02:59:27PM +0100, Henke, Markus wrote:
> >   So yes this creates a reference to the external subset. But that
> > reference is contained in the document and hence kept as part of the
> > internal subset informations.
>
> OK, that'll work for me ATM.
> But what's to do when i actually use an internal (build from scratch)
> *and* an (existing) external subset?
> When i create the *reference* to the external subset
> via xmlCreateIntSubset(), xmlDocPtr->intSubset points to the *external*
> subset!?

 it does it by name. Not by a pointer to the xmlDtdPtr.

> Who's than pointing to the internal subset, and where
> xmlDocPtr->extSubset is pointing to?

 this one points to the xmlDtdPtr of the external subset.

In a nutshell if you have internal and external subsets:
   - The DOCTYPE declaration generates an xmlDtdPtr node which is
     one of the children of the xmlDocPtr (before the root element)
   - This xmlDtdPtr is also referenced from the xmlDocPtr as 
     xmlDocPtr->intSubset
   - the external subset System ID and Public ID are stored in this
     xmlDocPtr->intSubset because they are actually carried by the DOCTYPE
     as xmlDocPtr->intSubset->ExternalID and xmlDocPtr->intSubset->SystemID
   - the external subset (if parsed which is not the default behaviour)
     is stored as xmlDocPtr->extSubset

If you have no external subset but an internal subset:
   - xmlDocPtr->extSubset is NULL
   - xmlDocPtr->intSubset->ExternalID and xmlDocPtr->intSubset->SystemID are
     NULL

If you have no internal subset but an external subset:
   - it's like the case where both are present except xmlDocPtr->intSubset
     have no children

If you have no internal subset nor external subset:
   - both xmlDocPtr->intSubset and xmlDocPtr->extSubset are NULL
   - there should be no xmlDtdPtr in the full document tree.

 I hope this clear things up,

Daniel

-- 
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