use of org.drools.mvel.dataproviders.MVELDataProvider in project drools by kiegroup.
the class MVELFromBuilder method build.
public RuleConditionElement build(final RuleBuildContext context, final BaseDescr descr, final Pattern prefixPattern) {
String text = ((FromDescr) descr).getExpression();
Optional<EntryPointId> entryPointId = context.getEntryPointId(text);
if (entryPointId.isPresent()) {
return entryPointId.get();
}
// This builder is re-usable in other dialects, so specify by name
MVELDialect dialect = (MVELDialect) context.getDialect("mvel");
boolean typeSafe = context.isTypesafe();
if (!dialect.isStrictMode()) {
context.setTypesafe(false);
}
try {
Map<String, Declaration> decls = context.getDeclarationResolver().getDeclarations(context.getRule());
AnalysisResult analysis = dialect.analyzeExpression(context, descr, text, new BoundIdentifiers(DeclarationScopeResolver.getDeclarationClasses(decls), context));
if (analysis == null) {
// something bad happened
return null;
}
Class<?> returnType = ((MVELAnalysisResult) analysis).getReturnType();
if (prefixPattern != null && !prefixPattern.isCompatibleWithFromReturnType(returnType)) {
context.addError(new DescrBuildError(descr, context.getRuleDescr(), null, "Pattern of type: '" + prefixPattern.getObjectType() + "' on rule '" + context.getRuleDescr().getName() + "' is not compatible with type " + returnType.getCanonicalName() + " returned by source"));
return null;
}
final BoundIdentifiers usedIdentifiers = analysis.getBoundIdentifiers();
final Declaration[] declarations = new Declaration[usedIdentifiers.getDeclrClasses().size()];
int j = 0;
for (String str : usedIdentifiers.getDeclrClasses().keySet()) {
declarations[j++] = decls.get(str);
}
Arrays.sort(declarations, SortDeclarations.instance);
MVELCompilationUnit unit = dialect.getMVELCompilationUnit(text, analysis, declarations, null, null, context, "drools", KnowledgeHelper.class, false, MVELCompilationUnit.Scope.CONSEQUENCE);
MVELDataProvider dataProvider = new MVELDataProvider(unit, context.getDialect().getId());
From from = new From(dataProvider);
from.setResultPattern(prefixPattern);
MVELDialectRuntimeData data = (MVELDialectRuntimeData) context.getPkg().getDialectRuntimeRegistry().getDialectData("mvel");
data.addCompileable(from, dataProvider);
dataProvider.compile(data, context.getRule());
return from;
} catch (final Exception e) {
AsmUtil.copyErrorLocation(e, descr);
context.addError(new DescrBuildError(context.getParentDescr(), descr, null, "Unable to build expression for 'from' : " + e.getMessage() + " '" + text + "'"));
return null;
} finally {
context.setTypesafe(typeSafe);
}
}
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