Examples with VariableDeclarator org.drools.javaparser.ast.body.VariableDeclarator used on opensource projects

Example 1 with VariableDeclarator

use of org.drools.javaparser.ast.body.VariableDeclarator in project drools by kiegroup.

the class AccumulateVisitor method visitAccInlineCustomCode.

/**
 * By design this legacy accumulate (with inline custome code) visitor supports only with 1-and-only binding in the accumulate code/expressions.
 */
protected void visitAccInlineCustomCode(RuleContext context2, AccumulateDescr descr, MethodCallExpr accumulateDSL, PatternDescr basePattern, PatternDescr inputDescr) {
    context.pushExprPointer(accumulateDSL::addArgument);
    final MethodCallExpr functionDSL = new MethodCallExpr(null, "accFunction");
    String code = null;
    try {
        code = new String(IoUtils.readBytesFromInputStream(this.getClass().getResourceAsStream("/AccumulateInlineFunction.java")));
    } catch (IOException e1) {
        e1.printStackTrace();
        throw new RuntimeException("Unable to locate template.");
    }
    String targetClassName = StringUtil.toId(context2.getRuleDescr().getName()) + "Accumulate" + descr.getLine();
    code = code.replaceAll("AccumulateInlineFunction", targetClassName);
    CompilationUnit templateCU = JavaParser.parse(code);
    ClassOrInterfaceDeclaration templateClass = templateCU.getClassByName(targetClassName).orElseThrow(() -> new RuntimeException("Template did not contain expected type definition."));
    ClassOrInterfaceDeclaration templateContextClass = templateClass.getMembers().stream().filter(m -> m instanceof ClassOrInterfaceDeclaration && ((ClassOrInterfaceDeclaration) m).getNameAsString().equals("ContextData")).map(ClassOrInterfaceDeclaration.class::cast).findFirst().orElseThrow(() -> new RuntimeException("Template did not contain expected type definition."));
    List<String> contextFieldNames = new ArrayList<>();
    MethodDeclaration initMethod = templateClass.getMethodsByName("init").get(0);
    BlockStmt initBlock = JavaParser.parseBlock("{" + descr.getInitCode() + "}");
    for (Statement stmt : initBlock.getStatements()) {
        if (stmt instanceof ExpressionStmt && ((ExpressionStmt) stmt).getExpression() instanceof VariableDeclarationExpr) {
            VariableDeclarationExpr vdExpr = (VariableDeclarationExpr) ((ExpressionStmt) stmt).getExpression();
            for (VariableDeclarator vd : vdExpr.getVariables()) {
                contextFieldNames.add(vd.getNameAsString());
                templateContextClass.addField(vd.getType(), vd.getNameAsString(), Modifier.PUBLIC);
                if (vd.getInitializer().isPresent()) {
                    Expression initializer = vd.getInitializer().get();
                    Expression target = new FieldAccessExpr(new NameExpr("data"), vd.getNameAsString());
                    Statement initStmt = new ExpressionStmt(new AssignExpr(target, initializer, AssignExpr.Operator.ASSIGN));
                    initMethod.getBody().get().addStatement(initStmt);
                }
            }
        } else {
            // add as-is.
            initMethod.getBody().get().addStatement(stmt);
        }
    }
    Type singleAccumulateType = JavaParser.parseType("java.lang.Object");
    MethodDeclaration accumulateMethod = templateClass.getMethodsByName("accumulate").get(0);
    BlockStmt actionBlock = JavaParser.parseBlock("{" + descr.getActionCode() + "}");
    Collection<String> allNamesInActionBlock = collectNamesInBlock(context2, actionBlock);
    if (allNamesInActionBlock.size() == 1) {
        String nameExpr = allNamesInActionBlock.iterator().next();
        accumulateMethod.getParameter(1).setName(nameExpr);
        singleAccumulateType = context2.getDeclarationById(nameExpr).get().getType();
    } else {
        new LegacyAccumulate(context, descr, basePattern).build();
        return;
    }
    writeAccumulateMethod(contextFieldNames, singleAccumulateType, accumulateMethod, actionBlock);
    // <result expression>: this is a semantic expression in the selected dialect that is executed after all source objects are iterated.
    MethodDeclaration resultMethod = templateClass.getMethodsByName("getResult").get(0);
    Type returnExpressionType = JavaParser.parseType("java.lang.Object");
    Expression returnExpression = JavaParser.parseExpression(descr.getResultCode());
    if (returnExpression instanceof NameExpr) {
        returnExpression = new EnclosedExpr(returnExpression);
    }
    rescopeNamesToNewScope(new NameExpr("data"), contextFieldNames, returnExpression);
    resultMethod.getBody().get().addStatement(new ReturnStmt(returnExpression));
    MethodDeclaration getResultTypeMethod = templateClass.getMethodsByName("getResultType").get(0);
    getResultTypeMethod.getBody().get().addStatement(new ReturnStmt(new ClassExpr(returnExpressionType)));
    if (descr.getReverseCode() != null) {
        MethodDeclaration supportsReverseMethod = templateClass.getMethodsByName("supportsReverse").get(0);
        supportsReverseMethod.getBody().get().addStatement(JavaParser.parseStatement("return true;"));
        MethodDeclaration reverseMethod = templateClass.getMethodsByName("reverse").get(0);
        BlockStmt reverseBlock = JavaParser.parseBlock("{" + descr.getReverseCode() + "}");
        Collection<String> allNamesInReverseBlock = collectNamesInBlock(context2, reverseBlock);
        if (allNamesInReverseBlock.size() == 1) {
            reverseMethod.getParameter(1).setName(allNamesInReverseBlock.iterator().next());
        } else {
            new LegacyAccumulate(context, descr, basePattern).build();
            return;
        }
        writeAccumulateMethod(contextFieldNames, singleAccumulateType, reverseMethod, reverseBlock);
    } else {
        MethodDeclaration supportsReverseMethod = templateClass.getMethodsByName("supportsReverse").get(0);
        supportsReverseMethod.getBody().get().addStatement(JavaParser.parseStatement("return false;"));
        MethodDeclaration reverseMethod = templateClass.getMethodsByName("reverse").get(0);
        reverseMethod.getBody().get().addStatement(JavaParser.parseStatement("throw new UnsupportedOperationException(\"This function does not support reverse.\");"));
    }
    // add resulting accumulator class into the package model
    this.packageModel.addGeneratedPOJO(templateClass);
    functionDSL.addArgument(new ClassExpr(JavaParser.parseType(targetClassName)));
    functionDSL.addArgument(new NameExpr(toVar(inputDescr.getIdentifier())));
    final String bindingId = basePattern.getIdentifier();
    final MethodCallExpr asDSL = new MethodCallExpr(functionDSL, "as");
    asDSL.addArgument(new NameExpr(toVar(bindingId)));
    accumulateDSL.addArgument(asDSL);
    context.popExprPointer();
}