6:54 a.m.
Hi
I'm currently trying to create a simple example in converting a DRL rule
into an XML rule and compiling that but it seems that the XML conversion is
not working correctly or have I done something wrong? Has anyone noticed
this problem too?
public static String convertDrlToXmlRule(String drlRule) throws
DroolsParserException
{
DrlParser parser = new DrlParser();
PackageDescr descr = parser.parse(drlRule);
// Dump to xml rule.
XmlDumper dumper = new XmlDumper();
return dumper.dump(descr);
}
the code above converts a drlRule and dumps out an XML format.
My example drl rule (this compiles fine):
public static String exampleRule = "package com.rules;" +
"import com.rules.my.test.Message;" +
"import com.rules.my.test.SubMessage;" +
"import com.rules.my.test.SubSubMessage;" +
"rule \"exampleRule\"" +
" dialect \"mvel\"" +
" when" +
" Message( $subMessage :
subMessage)\n" +
" SubMessage( $subSubMessage :
subSubMessage) from $subMessage\n" +
" SubSubMessage( message ==
\"SubSub\") from $subSubMessage\n" +
" \nthen\n" +
" System.out.println( $subMessage );"
+
" end";
What comes out:
<?xml version="1.0" encoding="UTF-8"?>
<package name="com.rules"
xmlns="http://drools.org/drools-4.0"
xmlns:xs="http://www.w3.org/2001/XMLSchema-instance"
xs:schemaLocation="http://drools.org/drools-4.0 drools-4.0.xsd">
<import name="com.rules.my.test.Message" />
<import name="com.rules.my.test.SubMessage" />
<import name="com.rules.my.test.SubSubMessage" />
<rule name="exampleRule ">
<rule-attribute name="dialect" value="mvel" />
<lhs>
<pattern object-type="Message" >
<field-binding field-name="subMessage"
identifier="$subMessage" />
</pattern>
<pattern object-type="SubMessage" >
<field-binding field-name="subSubMessage"
identifier="$subSubMessage" />
<field-binding field-name="subSubMessage"
identifier="$subSubMessage" />
<from>
<expression> $subMessage </expression>
</from>
</pattern>
<pattern object-type="SubSubMessage" >
<field-constraint field-name="message">
<literal-restriction evaluator="==" value="SubSub"
/>
</field-constraint>
<field-constraint field-name="message">
<literal-restriction evaluator="==" value="SubSub"
/>
</field-constraint>
<from>
<expression> $subSubMessage </expression>
</from>
</pattern>
</lhs>
<rhs>
System.out.println( $subMessage );
</rhs>
</rule>
</package>
If you noticed above it comes out with duplicate field-constaints for
pattern SubSubMessage?? However, thats not a big problem, when I try to
compile the rule in XML format it throws:
org.xml.sax.SAXParseException: <from> is after an invalid element:
org.drools.xml.Handler
at org.drools.xml.XmlPackageReader.validate(XmlPackageReader.java:506)
at
org.drools.xml.XmlPackageReader.startElement(XmlPackageReader.java:394)
at org.apache.xerces.parsers.AbstractSAXParser.startElement(Unknown
Source)
at org.apache.xerces.impl.xs.XMLSchemaValidator.startElement(Unknown
Source)
at
org.apache.xerces.impl.XMLNSDocumentScannerImpl.scanStartElement(Unknown
Source)
at
org.apache.xerces.impl.XMLDocumentFragmentScannerImpl$FragmentContentDispatcher.dispatch(Unknown
Source)
at
org.apache.xerces.impl.XMLDocumentFragmentScannerImpl.scanDocument(Unknown
Source)
at org.apache.xerces.parsers.XML11Configuration.parse(Unknown Source)
at org.apache.xerces.parsers.XML11Configuration.parse(Unknown Source)
at org.apache.xerces.parsers.XMLParser.parse(Unknown Source)
at org.apache.xerces.parsers.AbstractSAXParser.parse(Unknown Source)
at org.apache.xerces.jaxp.SAXParserImpl$JAXPSAXParser.parse(Unknown
Source)
at org.apache.xerces.jaxp.SAXParserImpl.parse(Unknown Source)
at org.drools.xml.XmlPackageReader.read(XmlPackageReader.java:321)
at org.drools.xml.XmlPackageReader.read(XmlPackageReader.java:247)
Any suggestions in what I am doing wrong?
Cheers,
Le.