219 DBMS_XSLPROCESSOR

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

This chapter contains the following topics:

219.1 DBMS_XSLPROCESSOR 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

219.2 DBMS_XSLPROCESSOR Security Model

Owned by XDB, the DBMS_XSLPROCESSOR package must be created by SYS or XDB. The EXECUTE privilege is granted to PUBLIC. Subprograms in this package are executed using the privileges of the current user.

219.3 Summary of DBMS_XSLPROCESSOR Subprograms

This table lists the DBMS_XSLPROCESSOR subprograms and briefly describes them.

Table 219-1 DBMS_XSLPROCESSOR Package Subprograms

Method Description

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

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

219.3.1 FREEPROCESSOR Procedure

This procedure frees a Processor object.

Syntax

DBMS_XSLPROCESSOR.FREEPROCESSOR(
  p  IN  Processor);

Parameters

Table 219-2 FREEPROCESSOR Procedure Parameters

Parameter Description

p

Processor

219.3.2 FREESTYLESHEET Procedure

This procedure frees a Stylesheet object.

Syntax

DBMS_XSLPROCESSOR.FREESTYLESHEET(
  ss  IN  Stylesheet);

Parameters

Table 219-3 FREESTYLESHEET Procedure Parameters

Parameter Description

ss

Stylesheet

219.3.3 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;

219.3.4 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 219-4 NEWSTYLESHEET Function Parameters

Parameter Description

xmldoc

DOMDocument to use for construction

inp

Input URL to use for construction

ref

Reference URL

219.3.5 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 219-5 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

219.3.6 REMOVEPARAM Procedure

This procedure removes a top level stylesheet parameter.

Syntax

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

Parameters

Table 219-6 REMOVEPARAM Procedure Parameters

Parameter Description

ss

Stylesheet instance

name

Name of the parameter

219.3.7 RESETPARAMS Procedure

This procedure resets the top-level stylesheet parameters.

Syntax

DBMS_XSLPROCESSOR.RESETPARAMS(
   ss  IN   Stylesheet);

Parameters

Table 219-7 RESETPARAMS Procedure Parameters

Parameter Description

ss

Stylesheet instance

219.3.8 SELECTNODES Function

This function selects nodes which match the supplied 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 219-8 SELECTNODES Function Parameters

Parameter Description

n

Root DOMNode of the tree

pattern

Pattern to use

namespace

Namespace declared

219.3.9 SELECTSINGLENODE Function

This function selects the first node from the tree that match the supplied 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 219-9 SELECTSINGLENODE Function Parameters

Parameter Description

n

Root DOMNode of the tree

pattern

Pattern to use

namespace

Namespace declared

219.3.10 SETERRORLOG Procedure

This deprecated 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 219-10 SETERRORLOG Procedure Parameters

Parameter Description

p

Processor instance

fileName

Complete path of the file to use as the error log

219.3.11 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 219-11 SETPARAM Procedure Parameters

Parameter Description

ss

Stylesheet instance

name

Name of the parameter

value

Value of the parameter

219.3.12 SHOWWARNINGS Procedure

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

Syntax

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

Parameters

Table 219-12 SHOWWARNINGS Procedure Parameters

Parameter Description

p

Processor instance

yes

Mode to set: TRUE to show warnings, FALSE otherwise

219.3.13 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 219-13 TRANSFORMNODE Function Parameters

Parameter Description

n

DOMNode to transform

ss

Stylesheet to use

219.3.14 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 219-14 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