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Oracle9i Application Developer's Guide - XML
Release 1 (9.0.1)

Part Number A88894-01
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G
XDK for PL/SQL: Specifications and Cheat Sheets

This Appendix describes Oracle XDK for PL/SQL specifications and includes syntax cheat sheets. It contains the following sections:

XML Parser for PL/SQL

XML documents are made up of storage units called entities, which contain either parsed or unparsed data. Parsed data is made up of characters, some of which form character data, and some of which form markup. Markup encodes a description of the document's storage layout and logical structure. XML provides a mechanism to impose constraints on the storage layout and logical structure.

A software module called an XML processor is used to read XML documents and provide access to their content and structure. It is assumed that an XML processor is doing its work on behalf of another module, called the application.

Oracle XML Parser Features

The XML Parser for PL/SQL parses an XML document (or a standalone DTD) so that it can be processed by an application. Library and command-line versions are provided supporting the following standards and features:

Additional features include:

Version 2 of the Oracle XML Parsers include an integrated XSL-Transformation (XSL-T) Processor for transforming XML data using XSL stylesheets. Using the XSL-T processor, you can transform XML documents from XML to XML, HTML, or virtually any other text-based format. These processors support the following standards and features:

Namespace Support

The Java, C, and C++ parsers also support XML Namespaces. Namespaces are a mechanism to resolve or avoid name collisions between element types (tags) or attributes in XML documents. This mechanism provides "universal" namespace element types and attribute names whose scope extends beyond the containing document. Such tags are qualified by uniform resource identifiers (URIs), such as <oracle:EMP xmlns:oracle="http://www.oracle.com/xml"/>. For example, namespaces can be used to identify an Oracle <EMP> data element as distinct from another company's definition of an <EMP> data element. This enables an application to more easily identify elements and attributes it is designed to process. The Java, C, and C++ parsers support namespaces by being able to recognize and parse universal element types and attribute names, as well as unqualified "local" element types and attribute names.

Validating and Non-Validating Mode Support

The Java, C, and C++ parsers can parse XML in validating or non-validating modes. In non-validating mode, the parser verifies that the XML is well-formed and parses the data into a tree of objects that can be manipulated by the DOM API. In validating mode, the parser verifies that the XML is well-formed and validates the XML data against the DTD (if any). Validation involves checking whether or not the attribute names and element tags are legal, whether nested elements belong where they are, and so on.

Example Code

See Chapter 29, "Using XML Parser for PL/SQL" for example code and suggestions on how to use the XML Parsers.

IXML Parser for PL/SQL Directory Structure

The following lists the XML Parser for PL/SQL directory structure in $ORACLE_HOME/xdk/plsql/parser:

DOM and SAX APIs

XML APIs generally fall into two categories: event-based and tree-based. An event-based API (such as SAX) uses callbacks to report parsing events to the application. The application deals with these events through customized event handlers. Events include the start and end of elements and characters. Unlike tree-based APIs, event-based APIs usually do not build in-memory tree representations of the XML documents. Therefore, in general, SAX is useful for applications that do not need to manipulate the XML tree, such as search operations, among others. For example, the following XML document:

<?xml version="1.0"?>
  <EMPLIST>
    <EMP>
     <ENAME>MARTIN</ENAME>
    </EMP>
    <EMP>
     <ENAME>SCOTT</ENAME>
    </EMP>
  </EMPLIST>

Becomes a series of linear events:

start document
start element: EMPLIST
start element: EMP
start element: ENAME
characters: MARTIN
end element: EMP
start element: EMP
start element: ENAME
characters: SCOTT
end element: EMP 
end element: EMPLIST
end document

A tree-based API (such as DOM) builds an in-memory tree representation of the XML document. It provides classes and methods for an application to navigate and process the tree. In general, the DOM interface is most useful for structural manipulations of the XML tree, such as reordering elements, adding or deleting elements and attributes, renaming elements, and so on.

XML Parser for PL/SQL Specifications

These are the Oracle XML Parser for PL/SQL specifications:

This PL/SQL implementation of the XML processor (or parser) follows the W3C XML specification (rev REC-xml-19980210) and included the required behavior of an XML processor in terms of how it must read XML data and the information it must provide to the application.

XML Parser for PL/SQL: Default Behavior

The following is the default behavior for this PLSQL XML parser:

The types and methods described in this document are made available by the PLSQL package xmlparser.

Supported Character Set Encodings

Supports documents in the following Oracle database encodings:

Default:

UTF-8 is the default encoding if none is specified. Any other ASCII or EBCDIC based encodings that are supported by the Oracle 9i database may be used.

Requirements

Oracle9i database with the Java option enabled.

Online Documentation

Documentation for Oracle XML Parser for PL/SQL is located in the doc directory in your install area and also in Oracle9i XML Reference.

Release Specific Notes

The Oracle XML parser for PL/SQL is an early adopter release and is written in PL/SQL and Java. It will check if an XML document is well-formed and, optionally, if it is valid. The parser will construct an object tree which can be accessed via PLSQL interfaces.

Standards Conformance

The parser conforms to the following standards:

W3C recommendation for Extensible Markup Language (XML) 1.0 at http://www.w3.org/TR/1998/REC-xml-19980210

W3C recommendation for Document Object Model Level 1 1.0 at http://www.w3.org/TR/REC-DOM-Level-1/

The parser currently does not currently have SAX or Namespace support. These will be made available in a future version.

Error Recovery

The parser also provides error recovery. It will recover from most errors and continue processing until a fatal error is encountered.

Important note: The contents of both the Windows and UNIX versions are identical. They are simply archived differently for operating system compatibility and your convenience.

XML Parser for PL/SQL: Parser() API

Table G-1 lists the XML Parser for PL/SQL Parser() API functions.

Table G-1 XML Parser for PL/SQL: Parser() API
Parser() Functions  Description 

parse(VARCHAR2) 

Parses xml stored in the given url/file and returns the built DOM Document  

newParser 

Returns a new parser instance  

parse(Parser, VARCHAR2) 

Parses xml stored in the given url/file  

parseBuffer(Parser, VARCHAR2) 

Parses xml stored in the given buffer  

parseClob(Parser, CLOB) 

Parses xml stored in the given clob  

parseDTD(Parser, VARCHAR2, VARCHAR2) 

Parses xml stored in the given url/file  

parseDTDBuffer(Parser, VARCHAR2, VARCHAR2) 

Parses xml stored in the given buffer 

parseDTDClob(Parser, CLOB, VARCHAR2) 

Parses xml stored in the given clob  

setBaseDir(Parser, VARCHAR2) 

Sets base directory used to resolve relative urls  

showWarnings(Parser, BOOLEAN) 

Turn warnings on or off  

setErrorLog(Parser, VARCHAR2) 

Sets errors to be sent to the specified file  

setPreserveWhitespace(Parser, BOOLEAN) 

Sets white space preserve mode  

setValidationMode(Parser, BOOLEAN) 

Sets validation mode  

getValidationMode(Parser) 

Gets validation mode  

setDoctype(Parser, DOMDocumentType) 

Sets DTD  

getDoctype(Parser) 

Gets DTD  

getDocument(Parser) 

Gets DOM document  

freeParser(Parser) 

Frees a Parser object  

XML Parser for PL/SQL: XSLT Processor API

Table G-2 lists the XML Parser for PL/SQL XSL-T Processor API functions.

for the following interfaces:

XML Parser for PL/SQL: W3C DOM API -- Types

The Document Object Model (DOM) is an application programming interface (API) for HTML and XML documents. It defines the logical structure of documents and the way a document is accessed and manipulated. In the DOM specification, the term "document" is used in the broad sense - increasingly, XML is being used as a way of representing many different kinds of information that may be stored in diverse systems, and much of this would traditionally be seen as data rather than as documents. Nevertheless, XML presents this data as documents, and the DOM may be used to manage this data.

The XML Parser for PL/SQL W3C DOM APIs are listed on OTN at the following site: http://otn.oracle.com/tech/xml


Table G-3 XML Parser for PL/SQL: W3C DOM API Types 
Types  DOMException types  DOM interface types 

DOM Node types 

INDEX_SIZE_ERR  

DOMNode  

ELEMENT_NODE  

DOMSTRING_SIZE_ERR  

DOMNamedNodeMap  

ATTRIBUTE_NODE  

HIERARCHY_REQUEST_ERR  

DOMNodeList  

TEXT_NODE  

WRONG_DOCUMENT_ERR  

DOMAttr  

CDATA_SECTION_NODE  

INVALID_CHARACTER_ERR  

DOMCDataSection  

ENTITY_REFERENCE_NODE  

NO_DATA_ALLOWED_ERR  

DOMCharacterData  

ENTITY_NODE  

NO_MODIFICATION_ALLOWED_ERR  

DOMComment  

PROCESSING_INSTRUCTION_NODE  

NOT_FOUND_ERR  

DOMDocumentFragment  

COMMENT_NODE  

NOT_SUPPORTED_ERR  

DOMElement  

DOCUMENT_NODE  

INUSE_ATTRIBUTE_ERR  

DOMEntity  

DOCUMENT_TYPE_NODE  

DOMException types 

DOMEntityReference  

DOCUMENT_FRAGMENT_NODE  

INDEX_SIZE_ERR  

DOMNotation  

NOTATION_NODE  

DOMSTRING_SIZE_ERR  

DOMProcessingInstruction  

 

 

DOMText  

 

 

DOMImplementation  

 

 

DOMDocumentType  

 

 

DOMDocument  

XML Parser for PL/SQL: W3C DOM API -- Node Methods, Node Types, and DOM Interface Types

Node Methods

The following lists the DOM API Node methods:

DOM Node Types

The following lists the DOM API Node types:

DOMException Types

The following lists the DOMException types:

DOM Interface Types

The following lists the DOM Interface types:


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