This function implements the standard XMLTest function, which
converts text into xml text nodes. It uses the libxml2 function
xmlEncodeSpecialChars to escape predefined entities (&"<>), so
that those do not cause any conflict when concatenating the text
node output with existing xml documents.
This also adds a note in features.sgml about not supporting
XML(SEQUENCE). The SQL specification defines a RETURNING clause
to a set of XML functions, where RETURNING CONTENT or RETURNING
SEQUENCE can be defined. Since PostgreSQL doesn't support
XML(SEQUENCE) all of these functions operate with an
implicit RETURNING CONTENT.
Author: Jim Jones <
[email protected]>
Reviewed-by: Vik Fearing <[email protected]>
Discussion: https://postgr.es/m/
86617a66-ec95-581f-8d54-
08059cca8885@uni-muenster.de
standard.
</para>
</listitem>
+
+ <listitem>
+ <para>
+ <productname>PostgreSQL</productname> does not support the
+ <literal>RETURNING CONTENT</literal> or <literal>RETURNING SEQUENCE</literal>
+ clauses, functions which are defined to have these in the specification
+ are implicitly returning content.
+ </para>
+ </listitem>
</itemizedlist>
</para>
documents for processing in client applications.
</para>
+ <sect3 id="functions-producing-xml-xmltext">
+ <title><literal>xmltext</literal></title>
+
+ <indexterm>
+ <primary>xmltext</primary>
+ </indexterm>
+
+<synopsis>
+<function>xmltext</function> ( <type>text</type> ) <returnvalue>xml</returnvalue>
+</synopsis>
+
+ <para>
+ The function <function>xmltext</function> returns an XML value with a single
+ text node containing the input argument as its content. Predefined entities
+ like ampersand (<literal><![CDATA[&]]></literal>), left and right angle brackets
+ (<literal><![CDATA[< >]]></literal>), and quotation marks (<literal><![CDATA[""]]></literal>)
+ are escaped.
+ </para>
+
+ <para>
+ Example:
+<screen><![CDATA[
+SELECT xmltext('< foo & bar >');
+ xmltext
+-------------------------
+ < foo & bar >
+]]></screen>
+ </para>
+ </sect3>
+
<sect3 id="functions-producing-xml-xmlcomment">
<title><literal>xmlcomment</literal></title>
X035 XMLAgg: ORDER BY option YES
X036 XMLComment YES
X037 XMLPI YES
-X038 XMLText NO
+X038 XMLText YES supported except for RETURNING
X040 Basic table mapping YES
X041 Basic table mapping: null absent YES
X042 Basic table mapping: null as nil YES
#ifdef USE_LIBXML
#include <libxml/chvalid.h>
+#include <libxml/entities.h>
#include <libxml/parser.h>
#include <libxml/parserInternals.h>
#include <libxml/tree.h>
}
+Datum
+xmltext(PG_FUNCTION_ARGS)
+{
+#ifdef USE_LIBXML
+ text *arg = PG_GETARG_TEXT_PP(0);
+ text *result;
+ xmlChar *xmlbuf = NULL;
+
+ xmlbuf = xmlEncodeSpecialChars(NULL, xml_text2xmlChar(arg));
+
+ Assert(xmlbuf);
+
+ result = cstring_to_text_with_len((const char *) xmlbuf, xmlStrlen(xmlbuf));
+ xmlFree(xmlbuf);
+ PG_RETURN_XML_P(result);
+#else
+ NO_XML_SUPPORT();
+ return 0;
+#endif /* not USE_LIBXML */
+}
+
/*
* TODO: xmlconcat needs to merge the notations and unparsed entities
{ oid => '2922', descr => 'serialize an XML value to a character string',
proname => 'text', prorettype => 'text', proargtypes => 'xml',
prosrc => 'xmltotext' },
+{ oid => '3813', descr => 'generate XML text node',
+ proname => 'xmltext', proisstrict => 't', prorettype => 'xml',
+ proargtypes => 'text', prosrc => 'xmltext' },
{ oid => '2923', descr => 'map table contents to XML',
proname => 'table_to_xml', procost => '100', provolatile => 's',
<foo/> | <foo/>
(1 row)
+SELECT xmltext(NULL);
+ xmltext
+---------
+
+(1 row)
+
+SELECT xmltext('');
+ xmltext
+---------
+
+(1 row)
+
+SELECT xmltext(' ');
+ xmltext
+---------
+
+(1 row)
+
+SELECT xmltext('foo `$_-+?=*^%!|/\()[]{}');
+ xmltext
+--------------------------
+ foo `$_-+?=*^%!|/\()[]{}
+(1 row)
+
+SELECT xmltext('foo & <"bar">');
+ xmltext
+-----------------------------------
+ foo & <"bar">
+(1 row)
+
+SELECT xmltext('x'|| '<P>73</P>'::xml || .42 || true || 'j'::char);
+ xmltext
+---------------------------------
+ x<P>73</P>0.42truej
+(1 row)
+
SELECT * FROM XMLTABLE('.' PASSING XMLELEMENT(NAME a) columns a varchar(20) PATH '"<foo/>"', b xml PATH '"<foo/>"');
ERROR: unsupported XML feature
DETAIL: This functionality requires the server to be built with libxml support.
+SELECT xmltext(NULL);
+ xmltext
+---------
+
+(1 row)
+
+SELECT xmltext('');
+ERROR: unsupported XML feature
+DETAIL: This functionality requires the server to be built with libxml support.
+SELECT xmltext(' ');
+ERROR: unsupported XML feature
+DETAIL: This functionality requires the server to be built with libxml support.
+SELECT xmltext('foo `$_-+?=*^%!|/\()[]{}');
+ERROR: unsupported XML feature
+DETAIL: This functionality requires the server to be built with libxml support.
+SELECT xmltext('foo & <"bar">');
+ERROR: unsupported XML feature
+DETAIL: This functionality requires the server to be built with libxml support.
+SELECT xmltext('x'|| '<P>73</P>'::xml || .42 || true || 'j'::char);
+ERROR: unsupported XML feature
+LINE 1: SELECT xmltext('x'|| '<P>73</P>'::xml || .42 || true || 'j':...
+ ^
+DETAIL: This functionality requires the server to be built with libxml support.
<foo/> | <foo/>
(1 row)
+SELECT xmltext(NULL);
+ xmltext
+---------
+
+(1 row)
+
+SELECT xmltext('');
+ xmltext
+---------
+
+(1 row)
+
+SELECT xmltext(' ');
+ xmltext
+---------
+
+(1 row)
+
+SELECT xmltext('foo `$_-+?=*^%!|/\()[]{}');
+ xmltext
+--------------------------
+ foo `$_-+?=*^%!|/\()[]{}
+(1 row)
+
+SELECT xmltext('foo & <"bar">');
+ xmltext
+-----------------------------------
+ foo & <"bar">
+(1 row)
+
+SELECT xmltext('x'|| '<P>73</P>'::xml || .42 || true || 'j'::char);
+ xmltext
+---------------------------------
+ x<P>73</P>0.42truej
+(1 row)
+
\x
SELECT * FROM XMLTABLE('.' PASSING XMLELEMENT(NAME a) columns a varchar(20) PATH '"<foo/>"', b xml PATH '"<foo/>"');
+
+SELECT xmltext(NULL);
+SELECT xmltext('');
+SELECT xmltext(' ');
+SELECT xmltext('foo `$_-+?=*^%!|/\()[]{}');
+SELECT xmltext('foo & <"bar">');
+SELECT xmltext('x'|| '<P>73</P>'::xml || .42 || true || 'j'::char);
\ No newline at end of file
projects / users / rhaas / postgres.git / commitdiff