177 DBMS_XSLPROCESSOR

The DBMS_XSLPROCESSOR package provides an interface to manage the contents and structure of XML documents.

This chapter contains the following topics:

Using DBMS_XSLPROCESSOR
- Overview
Summary of DBMS_XSLPROCESSOR Subprograms
See Also:
- Oracle XML DB Developer's Guide

Using DBMS_XSLPROCESSOR

This section contains topics which relate to using the DBMS_XSLPROCESSOR package.

Overview

Overview

The DBMS_XSLPROCESSOR package provides an interface to manage the contents and structure of XML documents.

Standards

This PL/SQL implementation of the XSL processor follows the W3C XSLT working draft rev WD-xslt-19990813 and includes the required behavior of an XSL processor in terms of how it must read XSLT stylesheets and the transformation it must effect.

Concepts

The Extensible Stylesheet Language Transformation (XSLT) describes rules for transforming a source tree into a result tree. A transformation expressed in XSLT is called a stylesheet. The transformation specified is achieved by associating patterns with templates defined in the stylesheet. A template is instantiated to create part of the result tree.

Implementation

The following is the default behavior for this PL/SQL XSL Processor:

A result tree which can be accessed by DOM programmatic interface
Errors are not recorded unless an error log is specified; however, an application error will be raised if parsing fails

Summary of DBMS_XSLPROCESSOR Subprograms

Table 177-1 DBMS_XSLPROCESSOR Package Subprograms

Method	Description
CLOB2FILE Procedure	Writes content of a `CLOB` into a file
FREEPROCESSOR Procedure	Frees a processor object
FREESTYLESHEET Procedure	Frees a stylesheet object
NEWPROCESSOR Function	Returns a new processor instance
NEWSTYLESHEET Functions	Creates a new stylesheet from input and reference URLs
PROCESSXSL Functions and Procedures	Transforms an input XML document
READ2CLOB Function	Reads content of the file into a `CLOB`
REMOVEPARAM Procedure	Removes a top-level stylesheet parameter
RESETPARAMS Procedure	Resets the top-level stylesheet parameters
SELECTNODES Function	Selects nodes from a DOM tree that match a pattern
SELECTSINGLENODE Function	Selects the first node from the tree that matches a pattern
SETERRORLOG Procedure	Sets errors to be sent to the specified file
SETPARAM Procedure	Sets a top-level parameter in the stylesheet
SHOWWARNINGS Procedure	Turns warnings on or off
TRANSFORMNODE Function	Transforms a node in a DOM tree using a stylesheet
VALUEOF Function and Procedure	Gets the value of the first node that matches a pattern

CLOB2FILE Procedure

This procedure writes content of a CLOB into a file.

Syntax

DBMS_XSLPROCESSOR.CLOB2FILE(
  cl          IN  CLOB;
  flocation   IN  VARCHAR2,
  fname       IN  VARCHAR2,
  csid        IN  NUMBER:=0);

Parameters

Table 177-2 CLOB2FILE Procedure Parameters

Parameter	Description
`CLOB`	File directory
`flocation`	File directory
`fname`	File name
`csid`	Character set id of the file Must be a valid Oracle id; otherwise returns an error If `0`, content of the output file will be in the database character set

FREEPROCESSOR Procedure

This procedure Frees a Processor object.

Syntax

DBMS_XSLPROCESSOR.FREEPROCESSOR(
  p  IN  Processor);

Parameters

Table 177-3 FREEPROCESSOR Procedure Parameters

Parameter	Description
`p`	Processor

FREESTYLESHEET Procedure

This procedure frees a Stylesheet object.

Syntax

DBMS_XSLPROCESSOR.FREESTYLESHEET(
  ss  IN  Stylesheet);

Parameters

Table 177-4 FREESTYLESHEET Procedure Parameters

Parameter	Description
`ss`	Stylesheet

NEWPROCESSOR Function

This function returns a new Processor instance. The function must be called before the default behavior of Processor can be changed and if other processor methods need to be used.

Syntax

DBMS_XSLPROCESSOR.NEWPROCESSOR
 RETURN Processor;

NEWSTYLESHEET Functions

This function creates and returns a new Stylesheet instance. The options are described in the following table.

Syntax

Creates and returns a new stylesheet instance using the given DOMDOCUMENT and reference URLs:

DBMS_XSLPROCESSOR.NEWSTYLESHEET(
   xmldoc  IN   DOMDOCUMENT,
   ref     IN   VARCHAR2) 
 RETURN Stylesheet;

Creates and returns a new Stylesheet instance using the given input and reference URLs:

DBMS_XSLPROCESSOR.NEWSTYLESHEET(
   inp    IN   VARCHAR2,
   ref    IN   VARCHAR2) 
 RETURN Stylesheet;

Parameters

Table 177-5 NEWSTYLESHEET Function Parameters

Parameter	Description
`xmldoc`	`DOMDocument` to use for construction
`inp`	Input URL to use for construction
`ref`	Reference URL

PROCESSXSL Functions and Procedures

This function transforms input XMLDocument. Any changes to the default processor behavior should be effected before calling this procedure. An application error is raised if processing fails.

Syntax

Transforms input XMLDocument using given DOMDocument and stylesheet, and returns the resultant document fragment:

DBMS_XSLPROCESSOR.PROCESSXSL(
   p      IN   Processor,
   ss     IN   Stylesheet,
   xmldoc IN   DOMDOCUMENT), 
 RETURN DOMDOCUMENTFRAGMENT;

Transforms input XMLDocument using given document as URL and the Stylesheet, and returns the resultant document fragment:

DBMS_XSLPROCESSOR.PROCESSXSL(
   p     IN   Processor,
   ss    IN   Stylesheet,
   url   IN   VARCHAR2, 
 RETURN DOMDOCUMENTFRAGMENT;

Transforms input XMLDocument using given document as CLOB and the Stylesheet, and returns the resultant document fragment:

DBMS_XSLPROCESSOR.PROCESSXSL(
   p     IN   Processor,
   ss    IN  Stylesheet,
   clb   IN  CLOB)
 RETURN DOMDOCUMENTFRAGMENT;

Transforms input XMLDocument using given DOMDOCUMENT and the stylesheet, and writes the output to the specified file:

DBMS_XSLPROCESSOR.DBMS_XSLPROCESSOR.(
   p           IN    Processor,
   ss          IN    Stylesheet,
   xmldoc      IN    DOMDOCUMENT,
   dir         IN    VARCHAR2,
   fileName    IN    VARCHAR2);

Transforms input XMLDocument using given URL and the stylesheet, and writes the output to the specified file in a specified directory:

DBMS_XSLPROCESSOR.PROCESSXSL(
   p          IN    Processor,
   ss         IN    Stylesheet,
   url        IN    VARCHAR2,
   dir        IN    VARCHAR2,
   fileName   IN    VARCHAR2);

Transforms input XMLDocument using given DOMDOCUMENT and the stylesheet, and writes the output to a CLOB:

DBMS_XSLPROCESSOR.PROCESSXSL(
   p          IN      Processor,
   ss         IN      Stylesheet,
   xmldoc     IN      DOMDOCUMENT,
   cl         IN OUT  CLOB);

Transforms input XMLDocument using given DOMDOCUMENTFRAGMENT and the stylesheet, and returns the resultant document fragment:

DBMS_XSLPROCESSOR.PROCESSXSL(
   p         IN    Processor,
   ss        IN    Stylesheet,
   xmldf     IN    DOMDOCUMENTFRAGMENT)
 RETURN DOMDOCUMENTFRAGMENT;

Transforms input XMLDocumentFragment using given DOMDocumentFragment and the stylesheet, and writes the output to the specified file in a specified directory:

DBMS_XSLPROCESSOR.PROCESSXSL(
   p         IN    Processor,
   ss        IN    Stylesheet,
   xmldf     IN    DOMDOCUMENTFRAGMENT,
   dir       IN    VARCHAR2,
   filename  IN    VARCHAR2);

Transforms input XMLDocumentFragment using given DOMDOCUMENTFRAGMENT and the stylesheet, and writes the output to a buffer:

DBMS_XSLPROCESSOR.PROCESSXSL(
   p          IN       Processor,
   ss         IN       Stylesheet,
   xmldf      IN       DOMDOCUMENTFRAGMENT,
   buf        IN OUT   VARCHAR2);

Transforms input XMLDocumentFragment using given DOMDOCUMENTFRAGMENT and the stylesheet, and writes the output to a CLOB:

DBMS_XSLPROCESSOR.PROCESSXSL(
   p          IN      Processor,
   ss         IN      Stylesheet,
   xmldf      IN      DOMDOCUMENTFRAGMENT,
   cl         IN OUT  CLOB);

Parameters

Table 177-6 PROCESSXSL Function and Procedure Parameters

Parameter	Description
`p`	`Processor` instance
`ss`	`Stylesheet` instance
`xmldoc`	XML document being transformed
`url`	URL for the information being transformed
`clb`	`CLOB` containing information to be transformed
`dir`	Directory where processing output file is saved
`filename`	Processing output file
`cl`	`CLOB` to which the processing output is saved
`xmldf`	`XMLDocumentFragment` being transformed

READ2CLOB Function

This function reads content of a file into a CLOB.

Syntax

DBMS_XSLPROCESSOR.READ2CLOB(
   flocation     IN   VARCHAR2,
   fname         IN   VARCHAR2,
   csid          IN   NUMBER:=0)
 RETURN CLOB;

Parameters

Table 177-7 READ2CLOB Function Parameters

Parameter Description

Parameter	Description
`flocation`	File directory
`fname`	File name
`csid`	Character set id of the file Must be a valid Oracle id; otherwise returns an error If `0`, input file is assumed to be in the database character set

flocation

File directory

fname

File name

csid

Character set id of the file

Must be a valid Oracle id; otherwise returns an error
If 0, input file is assumed to be in the database character set

REMOVEPARAM Procedure

This procedure removes a top level stylesheet parameter.

Syntax

DBMS_XSLPROCESSOR.REMOVEPARAM(
   ss     IN  Stylesheet,
   name   IN  VARCHAR2);

Parameters

Table 177-8 REMOVEPARAM Procedure Parameters

Parameter	Description
`ss`	`Stylesheet` instance
`name`	Name of the parameter

RESETPARAMS Procedure

This procedure resets the top-level stylesheet parameters.

Syntax

DBMS_XSLPROCESSOR.RESETPARAMS(
   ss  IN   Stylesheet);

Parameters

Table 177-9 RESETPARAMS Procedure Parameters

Parameter	Description
`ss`	`Stylesheet` instance

SELECTNODES Function

This function selects nodes which match the suplied path expression from a DOM tree, and returns the result of the selection.

Syntax

DBMS_XSLPROCESSOR.SELECTNODES( 
   n           IN   DBMS_XMLDOM.DOMNODE,
   pattern     IN   VARCHAR2,
   namespace   IN VARCHAR2 := NULL)
 RETURN DBMS_XMLDOM.DOMNODELIST;

Parameters

Table 177-10 SELECTNODES Function Parameters

Parameter	Description
`n`	Root `DOMNode` of the tree
`pattern`	Pattern to use
`namespace`	Namespace declared

SELECTSINGLENODE Function

This function selects the first node from the tree that match the suplied path expression, and returns that node.

Syntax

DBMS_XSLPROCESSOR.SELECTSINGLENODE(
   n           IN   DBMS_XMLDOM.DOMNODE,
   pattern     IN   VARCHAR2,
   namespace   IN VARCHAR2 := NULL)
 RETURN DBMS_XMLDOM.DOMNODE;

Parameters

Table 177-11 SELECTSINGLENODE Function Parameters

Parameter	Description
`n`	Root `DOMNode` of the tree
`pattern`	Pattern to use
`namespace`	Namespace declared

SETERRORLOG Procedure

This procedure sets errors to be sent to the specified file.

Note:

This subprogram has been deprecated, and is included only for reasons of backward compatibility.

Syntax

DBMS_XSLPROCESSOR.SETERRORLOG(
   p         IN   Processor,
   fileName  IN   VARCHAR2);

Parameters

Table 177-12 SETERRORLOG Procedure Parameters

Parameter	Description
`p`	`Processor` instance
`fileName`	Complete path of the file to use as the error log

SETPARAM Procedure

This procedure sets a top level parameter in the stylesheet. The parameter value must be a valid XPath expression. Literal string values must be quoted.

Syntax

DBMS_XSLPROCESSOR.SETPARAM(
   ss      IN   Stylesheet,
   name    IN   VARCHAR2,
   value   IN   VARCHAR2);

Parameters

Table 177-13 SETPARAM Procedure Parameters

Parameter	Description
`ss`	`Stylesheet` instance
`name`	Name of the parameter
`value`	Value of the parameter

SHOWWARNINGS Procedure

This procedure turns warnings on (TRUE) or off (FALSE).

Syntax

DBMS_XSLPROCESSOR.SHOWWARNINGS(
   p     IN   Processor,
   yes   IN   BOOLEAN);

Parameters

Table 177-14 SHOWWARNINGS Procedure Parameters

Parameter	Description
`p`	`Processor` instance
`yes`	Mode to set: `TRUE` to show warnings, `FALSE` otherwise

TRANSFORMNODE Function

This function transforms a node in a DOM tree using the given stylesheet, and returns the result of the transformation as a DOMDocumentFragment.

Syntax

DBMS_XSLPROCESSOR.TRANSFORMNODE(
   n    IN  DOMNODE,
   ss   IN  Stylesheet)
 RETURN DOMDocumentFragment;

Parameters

Table 177-15 TRANSFORMNODE Function Parameters

Parameter	Description
`n`	`DOMNode` to transform
`ss`	Stylesheet to use

VALUEOF Function and Procedure

This subprogram retrieves the value of the first node from the tree that matches the given pattern. You can use either a function or a procedure.

Syntax

DBMS_XSLPROCESSOR.VALUEOF(
  n           IN    DBMS_XMLDOM.DOMNODE,
  pattern     IN    VARCHAR2,
  namespace   IN    VARCHAR2 := NULL)
 RETURN VARCHAR2;

DBMS_XSLPROCESSOR.VALUEOF(
  n           IN    DBMS_XMLDOM.DOMNODE,
  pattern     IN    VARCHAR2,
  val         OUT   VARCHAR2,
  namespace   IN    VARCHAR2 := NULL);

Parameters

Table 177-16 VALUEOF Function and Procedure Parameters

Parameter	Description
`n`	Node whose value is being retrieved
`pattern`	Pattern to use
`val`	Retrieved value
namespace	Namespace to use