WARNING: this is outdated document. Please go to http://developer.postgresql.org/index.php/XML_Todo!

TODO

("+" means that the issue is resolved)

-- most important: --
 *  + !!! ability to parse both XML docs and chunks
 *     * error reporting (error messages by libxml's error codes) - finish
 *  ? encoding issues (convert to database encoding ?)
 *  + xmlpath non-standard function (xml _xmlpath(xml data, text query))
 *  * sql/xml functions according sql:2003/14
 *  -* xmlvalidate (dtd, xsd?) according sql:2003/14
 *  - type casting according sql:2003/14
 *  - documentation
 *  * !!! installation: fix USE_XML issue (*.c-s do not detect it now...) 
 *  - installation: --with-xml=<path>
 *  - installation: we cannot use #ifdef USE_XML in .bki files - find another way (straight SQL in initdb??)
 *  - xpath_array(): is it really necessary to use xmlChar2text before array accum? 
 *  - TESTING, EXAMPLES (regression tests?)

-- more: --
+    Finish initial things (see deliverables in the proposal:
    http://chernowiki.ru/index.php?node=87)

+     Support XML CONTENT and XML SEQUENCE as possible kinds of XML 
    type (according SQL/XML:4.2.2, 6.1, 10.16). As for sequence,
    to implement this fully is rather difficult task, because to do it
    we should be able to work with XQuery sequences - i.e. to have 
    XQuery processor (or at least part of it). The second difficulty is
    that implementing it in SQL/XML manner needs grammar hacking (TODO:
    think, how to do it w/o hacking, as alternative to SQL/XML syntax).
    One of subtasks for this global task is: to implement last steps of
    XMLPARSE according SQL/XML:10.16 (create XQuery document entity).

E    Implement SQL/XML syntax for XML type specs: XML(DOCUMENT(ANY)),
    XML(CONTENT(ANY)), etc (SQL/XML:4.2.2).
    
*    Parsing a binary sting as an XML value (SQL/XML:10.16).

E    {PRESERVE | STRIP} WHITESPACE options for XMLPARSE
    (SQL/XML:6.15, 10.16, Features X065, X066, X065, X066).

*    Function for escaping strings for xml data (encode entities) (non-standard?)

*     XPath function (what about standard? Seems that only XMLQUERY is present
    there - i.e. XQuery as more powerful and including XPath...)

*    Allow passing DTD to _xmlvalidate() as a simple VARCHAR string, not only as
    an URI.

*    Data manipulation (updates, insertes) according SQL/XML (SQL/XML:14)

*    Information schema according SQL/XML (SQL/XML:20); first of all, XML_SCHEMAS
    view.

-- SQL/XML publishing func-s: --
*    XMLDOCUMENT (SQL/XML:6.12)

*    XMLCAST (SQL/XML:6.5)

*    Integration with XML type (xml in, xml out)

+    Fix XMLCOMMENT - now it produces invalid comments ('<-- ... -->' instead of
    '<!-- ... -->')

*    Inline ORDER BY for XMLAGG: ...xmlagg(xmlelement(...) order by col1) ...

*    'RETURNING [ CONTENT | SEQUENCE ]' spec for XMLDOCUMENT, XMLAGG, XMLPI, ...

+    For XMLPI: first argument should be 'NAME ...' (so-called, PI target), 
    this syntax is similar to XMLELEMENT.

*    XMLTEXT (SQL/XML:6.18)

E    XMLPI now produces simple result, it do not worry about content.
     It's necessary to check, that the name of instruction is valid

+    Both statements are "valid" at the moment (fix grammar!):
     "select XMLPI(NAME 'aaa');" & "select XMLPI(NAME NAME 'aaa');"

E    XMLCONCAT (and others) should accept NULLs as input

E    This should work:
     select XMLCONCAT((select data from xmls where id = 1), 
         XMLELEMENT(name xx, '22'));

E    Look at the piece of grammar: "XMLELEMENT '(' NAME ColLabel ')'".
     "Bad" example: select xmlelement(name "A<!--111", '22'); => 
     produces invalid XML

*    Is this OK?
     template1=# select xmlelement(name test, xmlattributes(1 as a, 1 as a));
          xmlelement     
     ---------------------
      <test a="1" a="1"/>
    (1 row)

*    Not any <value expression> can be passed after name in xmlelement
     (check standard, maybe both cases are beyond XMLELEMENT definition):
     test=# select xmlelement(name a, 1, xmlelement(name b, 2));
     ERROR:  syntax error at or near ","
     LINE 1: select xmlelement(name a, 1, xmlelement(name b, 2));
                                        ^
     test=# select xmlelement(name a, xmlelement(name b, 2), 1);
         xmlelement    
     ------------------
      <a><b>2</b>1</a>
     (1 row)

*     Following stmt causes segfault:
      select text_xmlagg_accum('jhkj'::text, 'jhkjh'::text);

+     XMLPI is wrong now ("XMLPI '(' NAME a_expr ')'" in gram.y)
      It should accept 2 params: the name identifier and string value
      expression.

+     XMLPI and XMLCOMMENT: if NULL is given as <string value expression>,
      then NULL should be returned (now we have segfault on NULLs!)

*     XMLROOT: values for STANDALONE option now requre quotes ('), standard
      defines three "keyword" values: YES, NO, NO VALUE (w/o quotes).
      New keywords in grammar?..

*     XMLROOT: VERSION should be required param

*     ! XMLROOT was deleted in SQL/XML:2006 at all (XMLDOCUMENT added) !

*     XMLELEMENT: [...][{, <xml element content> } ... ] <right paren>
      Now, we can pass any number of child XMLELEMENTs, but (e.g.) this
      doesn't work: select xmlelement(name aaa, now(), now());

*     Doc (func.sgml) needs review

*     "Invalid PI name" when inserting XML docs with prolog into table.

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