DBMS_XSLPROCESSOR

218 DBMS_XSLPROCESSOR

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

This chapter contains the following topics:

218.1 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

218.2 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.

218.3 Summary of DBMS_XSLPROCESSOR Subprograms

This table lists the DBMS_XSLPROCESSOR subprograms and briefly describes them.

Table 218-1 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

218.3.1 FREEPROCESSOR Procedure

This procedure frees a Processor object.

Syntax

DBMS_XSLPROCESSOR.FREEPROCESSOR(
  p  IN  Processor);

Parameters

Table 218-2 FREEPROCESSOR Procedure Parameters

Parameter	Description
`p`	Processor

218.3.2 FREESTYLESHEET Procedure

This procedure frees a Stylesheet object.

Syntax

DBMS_XSLPROCESSOR.FREESTYLESHEET(
  ss  IN  Stylesheet);

Parameters

Table 218-3 FREESTYLESHEET Procedure Parameters

Parameter	Description
`ss`	Stylesheet

218.3.3 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;

218.3.4 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 218-4 NEWSTYLESHEET Function Parameters

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

218.3.5 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 218-5 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

218.3.6 REMOVEPARAM Procedure

This procedure removes a top level stylesheet parameter.

Syntax

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

Parameters

Table 218-6 REMOVEPARAM Procedure Parameters

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

218.3.7 RESETPARAMS Procedure

This procedure resets the top-level stylesheet parameters.

Syntax

DBMS_XSLPROCESSOR.RESETPARAMS(
   ss  IN   Stylesheet);

Parameters

Table 218-7 RESETPARAMS Procedure Parameters

Parameter	Description
`ss`	`Stylesheet` instance

218.3.8 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 218-8 SELECTNODES Function Parameters

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

218.3.9 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 218-9 SELECTSINGLENODE Function Parameters

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

218.3.10 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 218-10 SETERRORLOG Procedure Parameters

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

218.3.11 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 218-11 SETPARAM Procedure Parameters

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

218.3.12 SHOWWARNINGS Procedure

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

Syntax

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

Parameters

Table 218-12 SHOWWARNINGS Procedure Parameters

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

218.3.13 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 218-13 TRANSFORMNODE Function Parameters

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

218.3.14 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 218-14 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