Adding XML Objects to the Working Memory

ILOG JRules User Guide > Integrating Application Data > Tasks > Using the XML Binding API > Adding XML Objects to the Working Memory

Adding XML Objects to the Working Memory

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You can add XML objects to working memory using the API, or using an asserter. Using the API you can add only the top level (root) node, not any of the sub-nodes (leaves). Using an asserter, you can either add the whole tree to working memory, or just specific nodes.

A number of options are available when loading an XML document into the rule engine:

You can add just the root object of an XML document
You can add IlrXmlObject using the data driver
You can use an IlrXmlObjectAsserter object

To add the root object of an XML document:

Use the following code:

IlrXmlObject obj = driver.readObject(new FileReader(xmlFilename));

context.assert(obj);

By default, inserting the root object does not carry out a recursive add. If you want to process rules on sub objects of the graph, you must navigate the model using the in and from keywords in your rules.

Here is an extract from a rule named MatchSession1 rule:

rule MatchSession1 {

when {

   ?c: Conference();

   ?s: Session(?t: title.toLowerCase()) in ?c.sessionList;

   ?p: Participant() in ?c.participantList;

    collect String(?t.indexOf(toLowerCase()) != -1) in ?p.interestList

   where (size() >= 2);

...

To add IlrXmlObject using the data driver:

Use the following code:

IlrContext context = ... // an initialized rule engine

IlrXmlDefaultDataDriver driver = ...// an initialized driver

IlrXmlObject object = ... // an initialized object

try {

   driver.assertObjects ( objects, context, null );

} catch ( IlrXmlErrorException e ) {

   // some parsing errors

Alternatively, to add selected classes rather than the whole tree, replace:

driver.assertObjects ( objects, context, null );

with

driver.assertObjects ( objects, context, selectedClasses );

To use an IlrXmlObjectAsserter object:

Use the following code:

IlrXmlObjectAsserter asserter = new

   IlrXmlObjectAsserter(context);

asserter.registerAllXmlClasses(); // Add all the objects

asserter.exploreObject (obj);

If you use an IlrXmlObjectAsserter, you can filter the objects inserted in the working memory. Here, all the objects have been inserted, so there is no need to use the in or from in your rules. Here is an extract fromthis type of rule:

rule processValidItem {

priority=high;

when {

   item: Item ( "waiting".equals(state) );

   product: Product ( id.equals( item.product ); stock >= item.quantity );

...

Related Concepts

XML Binding

Working Memory View

Related Tasks

Using XML Objects as Ruleset Parameters

Assigning the Root Element Name of an XML Object

Reading an XML Document

Writing to an XML Document

Managing Unknown Operators on Attributes and Elements

Configuring XML Binding

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