Re: [xml] Substitution of nested entity references

[Daniel Veillard <veillard redhat com>]

On Wed, Apr 10, 2002 at 05:24:25PM +0200, Henke, Markus wrote:
> Maybe i've expressed myself unclear. The already built tree contains
> XML_ENTITY_REF_NODEs as part of content of element nodes or attribute
> values. As above mentioned, e.g. a call to xmlGetProp() on such an
> attribute
> (e.g. <aElement aAttr="Text &i_contain_an_entity_ref; MoreText" />)
> results in something like
> value = "Text &i_am_a_nested_entity_ref; MoreText"
> which isn't the expected result.


  xmlGetProp() does
  ret = xmlNodeListGetString(node->doc, prop->children, 1);
  i.e. with inLine=1
  the loop in that function does:
------------------
        } else if (node->type == XML_ENTITY_REF_NODE) {
            if (inLine) {
                ent = xmlGetDocEntity(doc, node->name);
                if (ent != NULL)
                    ret = xmlStrcat(ret, ent->content);
                else {
                    ret = xmlStrcat(ret, node->content);
                }
            } else {
                xmlChar buf[2];
                buf[0] = '&'; buf[1] = 0;
                ret = xmlStrncat(ret, buf, 1);
                ret = xmlStrcat(ret, node->name);
                buf[0] = ';'; buf[1] = 0;
                ret = xmlStrncat(ret, buf, 1);
            }
        }
------------------
  So it should *not* return a value = "Text &i_am_a_nested_entity_ref; MoreText"
value ! And a simple script check confirms this:

paphio:~/XML -> python
Python 1.5.2 (#1, Jul  5 2001, 03:02:19)  [GCC 2.96 20000731 (Red Hat Linux 7.1 2 on linux-i386
Copyright 1991-1995 Stichting Mathematisch Centrum, Amsterdam
> > > import libxml2
> > > doc = libxml2.parseFile("tst.xml") 
> > > root = doc.getRootElement()
> > > print root.prop("aAttr")
Text content MoreText
> > >

> > So why are you trying to remove them. No really I can't understand.
>
> I wouldn't too, but i don't try to do so.
> I want to accumulate the (useful) content of the different node
> types (as child nodes of an entity declaration) with regard to the
> case where the child node again is an entity reference (and do a
> recursive call to xmlResolveEntityRef() in that case).
> It's all about to enable routines like xmlGetProp(),
> xmlNodeGetContent(), ... to result in a *complete* substitution
> of an entity reference. 

  Okay, so you're just gathering content of the subtree. It seems to
me that xmlNodeGetContent() does just this. the only change which may
be needed is to change the handling of XML_ENTITY_REF_NODE nodes to recurse
in the node->children when the node found is such an entity ref.

Daniel

-- 
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