package org.drools.rule.builder.dialect.mvel;
import java.util.HashMap;
import java.util.Map;
import org.drools.base.mvel.MVELCompilationUnit;
import org.drools.base.mvel.MVELEnabledExpression;
import org.drools.compiler.DescrBuildError;
import org.drools.compiler.Dialect;
import org.drools.rule.Declaration;
import org.drools.rule.MVELDialectRuntimeData;
import org.drools.rule.builder.EnabledBuilder;
import org.drools.rule.builder.RuleBuildContext;
public class MVELEnabledBuilder
implements
EnabledBuilder {
public void build(RuleBuildContext context) {
// pushing consequence LHS into the stack for variable resolution
context.getBuildStack().push( context.getRule().getLhs() );
try {
// This builder is re-usable in other dialects, so specify by name
MVELDialect dialect = (MVELDialect) context.getDialect( "mvel" );
Map<String,Class<?>> otherVars = new HashMap<String, Class<?>>();
otherVars.put( "rule", org.drools.rule.Rule.class );
Map<String, Declaration> declarations = context.getDeclarationResolver().getDeclarations(context.getRule());
Map<String, Class<?>>[] available = new Map[]{ context.getDeclarationResolver().getDeclarationClasses(context.getRule()), context.getPackageBuilder().getGlobals()};
Dialect.AnalysisResult analysis = dialect.analyzeExpression( context,
context.getRuleDescr(),
(String) context.getRuleDescr().getEnabled(),
available,
otherVars );
Declaration[] previousDeclarations = (Declaration[]) declarations.values().toArray( new Declaration[declarations.size()] );
String exprStr = (String) context.getRuleDescr().getEnabled();
exprStr = exprStr.substring( 1, exprStr.length()-1 )+" ";
MVELCompilationUnit unit = dialect.getMVELCompilationUnit( exprStr,
analysis,
previousDeclarations,
null,
otherVars,
context );
MVELEnabledExpression expr = new MVELEnabledExpression( unit,
dialect.getId() );
context.getRule().setEnabled( expr );
MVELDialectRuntimeData data = (MVELDialectRuntimeData) context.getPkg().getDialectRuntimeRegistry().getDialectData( dialect.getId() );
data.addCompileable( context.getRule(),
expr );
expr.compile( context.getPackageBuilder().getRootClassLoader() );
} catch ( final Exception e ) {
context.getErrors().add( new DescrBuildError( context.getParentDescr(),
context.getRuleDescr(),
null,
"Unable to build expression for 'enabled' : " + e.getMessage() + " '" + context.getRuleDescr().getEnabled() + "'" ) );
}
}
}