Openadaptor XML SupportOpenadaptor XML Support

Using openadaptor for XML processing

Oleg Dulin, dulino@dulinresearch.com, http://www.dulinresearch.com/

MotivationMotivation

• The ideas behind the components described in this presentation are driven by the necessity to be able to manipulate XML documents in the Openadaptor pipeline XML Parsing HTML scraping XSL Transformations XPath mapping between DOM elements and

DataObject attributes Storing XML documents in the relational database XML-based Web Services

DOM Support in DataObjectsDOM Support in DataObjects

• DOMDataObject component Parses an XML String into DOM tree Serializes DOM tree into an XML String XML FixedDOType

• Doesn’t make sense to hold on to more than one DOM tree at a time

• Additional attributes should be added to DOM tree Get and SetAttribute methods overriden to “fool” other

components into thinking that XML is really stored as a String

Also methods for getting the reference to DOM Document object

DOMDataObject to do listDOMDataObject to do list

• Add support for setting parser features

FileBufferSourceFileBufferSource

• In order to parse XML into DOM we needed to either: Write a source that parses an XML document Add support for InputStream in DataObject Write a source that loads an XML document

into a String and passes it to the DOMParserPipe (next slide)

• The third option was the easiest, but second one is under development

DOMParserPipeDOMParserPipe

Takes a simple DataObject with a String attribute containing XML document

Creates a new DOMDataObject that will contain parsed XML document as a DOM tree

DOMParserPipe to do listDOMParserPipe to do list

• Add suport for setting parser features

XSLTransformPipeXSLTransformPipe

• Applies XSL transform to a DOM tree stored in DOMDataObject

• Replaces it with the result as another DOMDataObject

ExamplesExamples

• Apply XSL transformations to an XML document (next slide)

XSL Transform ExampleXSL Transform Example

FileBufferSource (read a document and place it into a String buffer attribute)

DOMParserPipe (parse the document in the string buffer attribute)

XSLTransformPipe (apply XSL transform to the XML document to extract only the elements that we need)

FileSink (save the result XML document into a file)

Work in ProgressWork in Progress

• Components in the following slides are currently a work in progress

XPathFilterPipeXPathFilterPipe

• Uses XPath to map DOM element values onto DataObject attributes

• Presently under development A very simple version is currently in the

source repository

XML2DBSinkXML2DBSink

• Takes SQL statements from an XML document and executes them The idea is to use XSLTransformPipe to convert an

XML document into a series of SQL statements and execute them.

E.g.: store values from the XML document in the relational database

E.g.: trigger database events based on values in the XML document

• Currently under development

HTMLTidyPipeHTMLTidyPipe

• Uses Jtidy to convert an arbitrary HTML document into a well-formed XML document (XHTML) The resulting document can then be passed

to XSLTransformPipe or XPathFilterPipe to extract values out of the HTML document

• A.k.a. screen scraping

• Currently under development

InputStreamDataObjectInputStreamDataObject

• The idea is to support passing a handle to an InputStream through the pipeline Avoid reading the entire file into the buffer for

DOM parsing SOAP with attachments Support for streaming content in the pipeline

• Currently under development

XML-based Web ServicesXML-based Web Services

• SOAPSink The version currently in CVS is outdated Add support for delivering message to any

SOAP service

• SOAPSource SOAP-enable any adaptor Create web services out of practically any

legacy application