Thanks to the generous support of Torchbox (http://www.torchbox.com), I

have been able to significantly improve the contrib/xml XPath
integration code.

New features:

* XPath set-returning function allows multiple results from an several
XPath queries to be used as a virtual table.
* Using libxslt, XSLT transformations (with and without parameters) are
supported. (Caution: This support allows generic URL fetching from
within the backend as well).

I've removed the old code so that it is all libxml based. Rather than
attach as a patch, I've put the tar.gz (10k!) at
http://www.azuli.co.uk/pgxml-1.0.tar.gz
(all files in archive are xml/....).

I think this is worth replacing the contrib version with, even though
the function names have changed (though the same functionality is
there), because it includes a SRF and some SPI usage, in addition to
linking to an external library. And it isn't a big module! Obviously, I
understand that people might prefer to move it elsewhere, or might have
reservations about replacing an existing contrib module with an
incompatible one. I'm open to suggestions.

John Gray

contrib/xml/pgxml.sql.in

@@ -1,10 +1,57 @@
--- SQL for XML parser
+--SQL for XML parser
 
--- Adjust this setting to control where the objects get created.
-SET search_path TO public;
+CREATE OR REPLACE FUNCTION pgxml_parse(text) RETURNS bool
+	AS 'MODULE_PATHNAME' LANGUAGE 'c' WITH (isStrict);
 
-CREATE OR REPLACE FUNCTION pgxml_parse(text) RETURNS boolean
-    AS 'MODULE_PATHNAME' LANGUAGE c STRICT;
+CREATE OR REPLACE FUNCTION xpath_string(text,text) RETURNS text
+	AS 'MODULE_PATHNAME' LANGUAGE 'c' WITH (isStrict);
 
-CREATE OR REPLACE FUNCTION pgxml_xpath(text, text, text, text) RETURNS text
-    AS 'MODULE_PATHNAME' LANGUAGE c STRICT;
+CREATE OR REPLACE FUNCTION xpath_nodeset(text,text,text,text) RETURNS text
+	AS 'MODULE_PATHNAME' LANGUAGE 'c' WITH (isStrict);
+
+CREATE OR REPLACE FUNCTION xpath_number(text,text) RETURNS float4
+	AS 'MODULE_PATHNAME' LANGUAGE 'c' WITH (isStrict);
+
+CREATE OR REPLACE FUNCTION xpath_bool(text,text) RETURNS boolean
+	AS 'MODULE_PATHNAME' LANGUAGE 'c' WITH (isStrict);
+
+-- List function
+
+CREATE OR REPLACE FUNCTION xpath_list(text,text,text) RETURNS text
+	AS 'MODULE_PATHNAME'
+	LANGUAGE 'c' WITH (isStrict);
+
+
+CREATE OR REPLACE FUNCTION xpath_list(text,text) RETURNS text 
+AS 'SELECT xpath_list($1,$2,'','')' language 'SQL' WITH (isStrict);
+
+
+
+-- Wrapper functions for nodeset where no tags needed.
+
+
+CREATE OR REPLACE FUNCTION xpath_nodeset(text,text) RETURNS text AS
+'SELECT xpath_nodeset($1,$2,'''','''')' language 'SQL' WITH (isStrict);
+
+
+CREATE OR REPLACE FUNCTION xpath_nodeset(text,text,text) RETURNS text AS
+'SELECT xpath_nodeset($1,$2,'''',$3)' language 'SQL' WITH (isStrict);
+
+-- Table function
+
+CREATE OR REPLACE FUNCTION xpath_table(text,text,text,text,text) RETURNS setof record
+	AS 'MODULE_PATHNAME'
+	LANGUAGE 'c' WITH (isStrict);
+
+-- XSLT functions
+-- Delete from here to the end of the file if you are not compiling with
+-- XSLT support.
+
+
+CREATE OR REPLACE FUNCTION xslt_process(text,text,text) RETURNS text 
+	AS 'MODULE_PATHNAME' LANGUAGE 'c' WITH (isStrict);
+
+-- the function checks for the correct argument count
+
+CREATE OR REPLACE FUNCTION xslt_process(text,text) RETURNS text 
+	AS 'MODULE_PATHNAME' LANGUAGE 'c' WITH (isStrict);