# PLJSON_UTIL_PKG

## Package Specification

```sql
package pljson_util_pkg authid current_user as

  /*

  Purpose:    JSON utilities for PL/SQL
  see http://ora-00001.blogspot.com/

  Remarks:

  Who     Date        Description
  ------  ----------  -------------------------------------
  MBR     30.01.2010  Created
  JKR     01.05.2010  Edited to fit in PL/JSON
  JKR     19.01.2011  Newest stylesheet + bugfix handling

  */

  -- generate JSON from REF Cursor
  function ref_cursor_to_json (p_ref_cursor in sys_refcursor,
                               p_max_rows in number := null,
                               p_skip_rows in number := null) return pljson_list;

  -- generate JSON from SQL statement
  function sql_to_json (p_sql in varchar2,
                        p_max_rows in number := null,
                        p_skip_rows in number := null) return pljson_list;


end pljson_util_pkg;```

## Package Body

```sql
package body pljson_util_pkg as
  scanner_exception exception;
  pragma exception_init(scanner_exception, -20100);
  parser_exception exception;
  pragma exception_init(parser_exception, -20101);

  /*

  Purpose:    JSON utilities for PL/SQL

  Remarks:

  Who     Date        Description
  ------  ----------  -------------------------------------
  MBR     30.01.2010  Created

  */

function get_xml_to_json_stylesheet return varchar2 as
  stylesheet varchar2(32767);
  nls_numeric_characters varchar2(2);
begin

  /*

  Purpose:    return XSLT stylesheet for XML to JSON transformation

  Remarks:    see http://code.google.com/p/xml2json-xslt/

  Who     Date        Description
  ------  ----------  -------------------------------------
  MBR     30.01.2010  Created
  MBR     30.01.2010  Added fix for nulls

  */

  stylesheet := q'^<?xml version="1.0" encoding="UTF-8"?>
<xsl:stylesheet version="1.0" xmlns:xsl="http://www.w3.org/1999/XSL/Transform">
<!--
  Copyright (c) 2006,2008 Doeke Zanstra
  All rights reserved.

  Redistribution and use in source and binary forms, with or without modification,
  are permitted provided that the following conditions are met:

  Redistributions of source code must retain the above copyright notice, this
  list of conditions and the following disclaimer. Redistributions in binary
  form must reproduce the above copyright notice, this list of conditions and the
  following disclaimer in the documentation and/or other materials provided with
  the distribution.

  THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
  ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
  WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
  IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT,
  INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
  BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
  LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
  OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF
  THE POSSIBILITY OF SUCH DAMAGE.
-->

  <xsl:output indent="no" omit-xml-declaration="yes" method="text" encoding="UTF-8" media-type="text/x-json"/>
        <xsl:strip-space elements="*"/>
  <!--contant-->
  <xsl:variable name="d">0123456789</xsl:variable>

  <!-- ignore document text -->
  <xsl:template match="text()[preceding-sibling::node() or following-sibling::node()]"/>

  <!-- string -->
  <xsl:template match="text()">
    <xsl:call-template name="escape-string">
      <xsl:with-param name="s" select="."/>
    </xsl:call-template>
  </xsl:template>

  <!-- Main template for escaping strings; used by above template and for object-properties
       Responsibilities: placed quotes around string, and chain up to next filter, escape-bs-string -->
  <xsl:template name="escape-string">
    <xsl:param name="s"/>
    <xsl:text>"</xsl:text>
    <xsl:call-template name="escape-bs-string">
      <xsl:with-param name="s" select="$s"/>
    </xsl:call-template>
    <xsl:text>"</xsl:text>
  </xsl:template>

  <!-- Escape the backslash (\) before everything else. -->
  <xsl:template name="escape-bs-string">
    <xsl:param name="s"/>
    <xsl:choose>
      <xsl:when test="contains($s,'\')">
        <xsl:call-template name="escape-quot-string">
          <xsl:with-param name="s" select="concat(substring-before($s,'\'),'\\')"/>
        </xsl:call-template>
        <xsl:call-template name="escape-bs-string">
          <xsl:with-param name="s" select="substring-after($s,'\')"/>
        </xsl:call-template>
      </xsl:when>
      <xsl:otherwise>
        <xsl:call-template name="escape-quot-string">
          <xsl:with-param name="s" select="$s"/>
        </xsl:call-template>
      </xsl:otherwise>
    </xsl:choose>
  </xsl:template>

  <!-- Escape the double quote ("). -->
  <xsl:template name="escape-quot-string">
    <xsl:param name="s"/>
    <xsl:choose>
      <xsl:when test="contains($s,'&quot;')">
        <xsl:call-template name="encode-string">
          <xsl:with-param name="s" select="concat(substring-before($s,'&quot;'),'\&quot;')"/>
        </xsl:call-template>
        <xsl:call-template name="escape-quot-string">
          <xsl:with-param name="s" select="substring-after($s,'&quot;')"/>
        </xsl:call-template>
      </xsl:when>
      <xsl:otherwise>
        <xsl:call-template name="encode-string">
          <xsl:with-param name="s" select="$s"/>
        </xsl:call-template>
      </xsl:otherwise>
    </xsl:choose>
  </xsl:template>

  <!-- Replace tab, line feed and/or carriage return by its matching escape code. Can't escape backslash
       or double quote here, because they don't replace characters (&#x0; becomes \t), but they prefix
       characters (\ becomes \\). Besides, backslash should be seperate anyway, because it should be
       processed first. This function can't do that. -->
  <xsl:template name="encode-string">
    <xsl:param name="s"/>
    <xsl:choose>
      <!-- tab -->
      <xsl:when test="contains($s,'&#x9;')">
        <xsl:call-template name="encode-string">
          <xsl:with-param name="s" select="concat(substring-before($s,'&#x9;'),'\t',substring-after($s,'&#x9;'))"/>
        </xsl:call-template>
      </xsl:when>
      <!-- line feed -->
      <xsl:when test="contains($s,'&#xA;')">
        <xsl:call-template name="encode-string">
          <xsl:with-param name="s" select="concat(substring-before($s,'&#xA;'),'\n',substring-after($s,'&#xA;'))"/>
        </xsl:call-template>
      </xsl:when>
      <!-- carriage return -->
      <xsl:when test="contains($s,'&#xD;')">
        <xsl:call-template name="encode-string">
          <xsl:with-param name="s" select="concat(substring-before($s,'&#xD;'),'\r',substring-after($s,'&#xD;'))"/>
        </xsl:call-template>
      </xsl:when>
      <xsl:otherwise><xsl:value-of select="$s"/></xsl:otherwise>
    </xsl:choose>
  </xsl:template>

  <!-- number (no support for javascript mantissa) -->
  <xsl:template match="text()[not(
                      (starts-with(., '0' ) and . !=  '0' and not(starts-with(., '0.' ))) or
                      (starts-with(.,'-0' ) and . != '-0' and not(starts-with(.,'-0.' ))) or
                      string(number(translate(., '{{nls_numeric_characters}}', '.,')))='NaN'
                      )]">

    <xsl:variable name="num_string" select="translate(., '{{nls_numeric_characters}}', '.,')"/>

    <xsl:choose>
      <xsl:when test="starts-with($num_string, '.')">
        <xsl:value-of select="concat('0', $num_string)"/>
      </xsl:when>
      <xsl:otherwise>
        <xsl:value-of select="$num_string"/>
      </xsl:otherwise>
    </xsl:choose>

  </xsl:template>

  <!-- boolean, case-insensitive -->
  <xsl:template match="text()[translate(.,'TRUE','true')='true']">true</xsl:template>
  <xsl:template match="text()[translate(.,'FALSE','false')='false']">false</xsl:template>

  <!-- object -->
  <xsl:template match="*" name="base">
    <xsl:if test="not(preceding-sibling::*)">{</xsl:if>
    <xsl:call-template name="escape-string">
      <xsl:with-param name="s" select="name()"/>
    </xsl:call-template>
    <xsl:text>:</xsl:text>
    <!-- check type of node -->
    <xsl:choose>
      <!-- null nodes -->
      <xsl:when test="count(child::node())=0">null</xsl:when>
      <!-- other nodes -->
      <xsl:otherwise>
        <xsl:apply-templates select="child::node()"/>
      </xsl:otherwise>
    </xsl:choose>
    <!-- end of type check -->
    <xsl:if test="following-sibling::*">,</xsl:if>
    <xsl:if test="not(following-sibling::*)">}</xsl:if>
  </xsl:template>

  <!-- array -->
  <xsl:template match="*[count(../*[name(../*)=name(.)])=count(../*) and count(../*)&gt;1]">
    <xsl:if test="not(preceding-sibling::*)">[</xsl:if>
    <xsl:choose>
      <xsl:when test="not(child::node())">
        <xsl:text>null</xsl:text>
      </xsl:when>
      <xsl:otherwise>
        <xsl:apply-templates select="child::node()"/>
      </xsl:otherwise>
    </xsl:choose>
    <xsl:if test="following-sibling::*">,</xsl:if>
    <xsl:if test="not(following-sibling::*)">]</xsl:if>
  </xsl:template>

  <!-- convert root element to an anonymous container -->
  <xsl:template match="/">
    <xsl:apply-templates select="node()"/>
  </xsl:template>

</xsl:stylesheet>^';

  select value
  into nls_numeric_characters
  from nls_session_parameters
  where parameter = 'NLS_NUMERIC_CHARACTERS';

  return replace(stylesheet, '{{nls_numeric_characters}}', nls_numeric_characters);

end get_xml_to_json_stylesheet;


function ref_cursor_to_json (p_ref_cursor in sys_refcursor,
                             p_max_rows in number := null,
                             p_skip_rows in number := null) return pljson_list
as
  l_ctx         dbms_xmlgen.ctxhandle;
  l_num_rows    pls_integer;
  l_xml         xmltype;
  l_xsl         xmltype         := xmltype(get_xml_to_json_stylesheet);
  l_returnvalue clob;
begin

  /*

  Purpose:    generate JSON from REF Cursor

  Remarks:

  Who     Date        Description
  ------  ----------  -------------------------------------
  MBR     30.01.2010  Created
  JKR     01.05.2010  Edited to fit in PL/JSON

  */

  l_ctx := dbms_xmlgen.newcontext (p_ref_cursor);

  dbms_xmlgen.setnullhandling (l_ctx, dbms_xmlgen.empty_tag);

  -- for pagination

  if p_max_rows is not null then
    dbms_xmlgen.setmaxrows (l_ctx, p_max_rows);
  end if;

  if p_skip_rows is not null then
    dbms_xmlgen.setskiprows (l_ctx, p_skip_rows);
  end if;

  -- get the XML content
  l_xml := dbms_xmlgen.getxmltype (l_ctx, dbms_xmlgen.none);

  l_num_rows := dbms_xmlgen.getnumrowsprocessed (l_ctx);

  dbms_xmlgen.closecontext (l_ctx);

  close p_ref_cursor;

  if(l_num_rows = 0) then
    return pljson_list();
  end if;

  --dbms_output.put_line(l_xml.getstringval);
  -- perform the XSL transformation
  SELECT  l_xml.transform(l_xsl).getclobval()
  INTO    l_returnvalue
  FROM    DUAL;

  --dbms_output.put_line(l_returnvalue);

  if(l_num_rows > 1) then
    return pljson_list(pljson(l_returnvalue).get('ROWSET'));
  end if;

  declare ret pljson_list := pljson_list();
  begin
    ret.append(
      pljson(
        pljson(l_returnvalue).get('ROWSET')
      ).get('ROW')
    );
    return ret;
  end;

exception
  when scanner_exception then
    dbms_output.put('Scanner problem with the following input: ');
    dbms_output.put_line(l_returnvalue);
    raise;
  when parser_exception then
    dbms_output.put('Parser problem with the following input: ');
    dbms_output.put_line(l_returnvalue);
    raise;
  when others then raise;
end ref_cursor_to_json;

function sql_to_json (p_sql in varchar2,
                      p_max_rows in number := null,
                      p_skip_rows in number := null) return pljson_list
as
  v_cur sys_refcursor;
begin
  open v_cur for p_sql;
  return ref_cursor_to_json(v_cur, p_max_rows, p_skip_rows);

end sql_to_json;

end pljson_util_pkg;```