[libxml++] proposed function to xmlpp::Node

[Julius M. <ju...@mu...>]

Hi all,

i would propose to add the attached function to xmlpp::Node.
This function tests whether the node or any subnode match with the =20
given xpath-expression.
( NodeSet find(const Glib::ustring& xpath); is not suitable for that =20
purpose, because some expressions don't return an NodeSet).

I would ask you to add this code snippet to the cvs-repository.

Best regards
/Julius

-----------------------------
libxml++/nodes/node.h:
-----------------------------

   /** Test nodes with XPath expression
    * @param xpath The XPath of the nodes.
    * @return True if any node matches the XPath expression, false =20
otherwise.
    */
    bool test(const Glib::ustring& xpath) const;

   /** Test nodes with XPath expression
    * @param xpath The XPath of the nodes.
    * @param namespaces A map of namespace prefixes to namespace URIs =20=

to be used while finding.
    * @return True if any node matches the XPath expression, false =20
otherwise.
    */
   bool test(const Glib::ustring& xpath, const PrefixNsMap& =20
namespaces) const;

-----------------------------
libxml++/nodes/node.cc:
-----------------------------

static bool test_impl(xmlXPathContext* ctxt, const Glib::ustring& xpath)
{
   bool ret;
   xmlXPathObject* result =3D xmlXPathEval((const xmlChar*)xpath.c_str=20=

(), ctxt);

   if(!result)
   {
     xmlXPathFreeContext(ctxt);
     throw exception("Invalid XPath: " + xpath);
   }

   ret =3D xmlXPathCastToBoolean(result);

   xmlXPathFreeObject(result);
   xmlXPathFreeContext(ctxt);

   return ret;
}

bool Node::test(const Glib::ustring& xpath) const
{
   xmlXPathContext* ctxt =3D xmlXPathNewContext(impl_->doc);
   ctxt->node =3D impl_;

   return test_impl(ctxt, xpath);
}

bool Node::test(const Glib::ustring& xpath,
                    const PrefixNsMap& namespaces) const
{
   xmlXPathContext* ctxt =3D xmlXPathNewContext(impl_->doc);
   ctxt->node =3D impl_;

   for (PrefixNsMap::const_iterator it=3Dnamespaces.begin();
        it !=3D namespaces.end(); it++)
     xmlXPathRegisterNs(ctxt,
                        reinterpret_cast<const xmlChar*>(it-=20
 >first.c_str()),
                        reinterpret_cast<const xmlChar*>(it-=20
 >second.c_str()));

   return test_impl(ctxt, xpath);
}

-----------------------------



--=20
GRIN Verlag GbR
Dr. Julius Mittenzwei
Marienstr. 17
80331 M=FCnchen

http://www.grin.com/
E-Mail: jm...@gr...
Tel: +49-(0)89-550559-12
Fax: +49-(0)89-550559-10