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Uche Ogbuji wrote:
> > Given the following XML in a DOM document
> >
> > <foo>
> > bar
> > <![CDATA[
> > baz
> > ]]>
> > quux
> > </foo>
> >
> > and the following XPath
> >
> > //text()
> >
> > what should be the resulting DOM nodes and why? I can think of two answers but they both have problems.
> >
> > PS: Why is http://www.w3.org/TR/2002/WD-DOM-Level-3-XPath-20020712/ returning a 404 when it is linked from http://www.w3.org/DOM/ ?
> >
>
> XPath is defined against a certain model of an XML document. The section that
> answers your question is 5.7:
>
> "Character data is grouped into text nodes. As much character data as possible
> is grouped into each text node: a text node never has an immediately following
> or preceding sibling that is a text node. The string-value of a text node is
> the character data. A text node always has at least one character of data.
>
> "Each character within a CDATA section is treated as character data. Thus,
> <![CDATA[<]]> in the source document will treated the same as <. Both will
> result in a single < character in a text node in the tree. Thus, a CDATA
> section is treated as if the <![CDATA[ and ]]> were removed and every
> occurrence of < and & were replaced by < and & respectively."
>
> Therefore to a conforming XPath processor,
>
> <foo>
> bar
> <![CDATA[
> baz
> ]]>
> quux
> </foo>
>
> Is precesely the same as
>
> <foo>
> bar
> baz
> quux
> </foo>
>
> i.e. one element node with one text node child.
>
> There is actually an open bug against 4XPath right now that it leaks a bit in
> this performance. e.g. in some cases, it can return a text node child of an
> attribute when operating on a DOM (this is so in DOM but not XPath). Your pos
> is a handy reminder for me to fix this bug.
>
> As an illustration, here's a session with 4XPath does (interactive Python
> prompt):
>
> >>> DOC = """<foo>
> ... bar
> ... <![CDATA[
> ... baz
> ... ]]>
> ... quux
> ... </foo>"""
> >>> from Ft.Xml.Domlette import NonvalidatingReader
> >>> doc = NonvalidatingReader.parseString(DOC, "http://dummybaseuri.com";)
> >>> from Ft.Xml.XPath import Evaluate
> >>> result = Evaluate("//text()", contextNode=doc)
> >>> print result
> [<cText at 0x81ae434>]
> >>> print result[0].data
>
> bar
>
> baz
>
> quux
>
> >>>
>
> --
> Uche Ogbuji Fourthought, Inc.
> http://uche.ogbuji.net http://4Suite.org http://fourthought.com
> Track chair, XML/Web Services One Boston: http://www.xmlconference.com/
> The many heads of XML modeling - http://adtmag.com/article.asp?id=6393
> Will XML live up to its promise? - http://www-106.ibm.com/developerworks/xml/li
> brary/x-think11.html
>
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--
Edward R Gloor
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