drools error [ERR 102] Line 40:43 mismatched input '&&' expecting ')' in rule "Free Fish Food Sample"

[mschwery]

I'm getting the drools error [ERR 102] Line 40:43 mismatched input '&&' expecting ')' in rule "Free Fish Food Sample"

in from the Pet Store sample in JBoss Developer Studio 4.0 CR1. Can anybody help me get rid of this error.

rule "Free Fish Food Sample"

    agenda-group "evaluate"

    dialect "mvel"

    when

        $order : Order()

        not ( $p : Product( name == "Fish Food") && Purchase( product == $p )

        not ( $p : Product( name == "Fish Food Sample") && Purchase( product == $p ) )       

        exists ( $p : Product( name == "Gold Fish") && Purchase( product == $p ) )   

        $fishFoodSample : Product( name == "Fish Food Sample" );

    then

        System.out.println( "Adding free Fish Food Sample to cart" );

        purchase = new Purchase($order, $fishFoodSample);

        insert( purchase );

        $order.addItem( purchase );   

end

[salaboy21]

Hi there.. Looks like the first not requires an extra parenthesis at the end right?

not ( $p : Product( name == "Fish Food") && Purchase( product == $p ))

Greetings.

[mschwery]

Still get the errors

[ERR 102] Line 40:43 mismatched input '&&' expecting ')' in rule "Free Fish Food Sample"

[ERR 102] Line 40:71 mismatched input ')' expecting 'then' in rule "Free Fish Food Sample"

[salaboy21]

Hi Mike,

Try with this:

rule "Free Fish Food Sample"

    agenda-group "evaluate"

    dialect "mvel"

    when

        $order : Order()

        not ( $p : Product( name == "Fish Food") && Purchase( product == $p ))

        not ( $p : Product( name == "Fish Food Sample") && Purchase( product == $p ) )       

        exists ( $p : Product( name == "Gold Fish") && Purchase( product == $p ) )   

        $fishFoodSample : Product( name == "Fish Food Sample" )

    then

        System.out.println( "Adding free Fish Food Sample to cart" );

        purchase = new Purchase($order, $fishFoodSample);

        insert( purchase );

        $order.addItem( purchase );   

end

I've added 1 closing parenthesis ) and I remove the ; in the last condition in the when part.

Greetings

[mschwery]

now it says

Unable to load dialect 'org.drools.rule.builder.dialect.mvel.MVELDialectConfiguration:mvel:org.drools.rule.builder.dialect.mvel.MVELDialectConfiguration'

[salaboy21]

Good, now the Rule is correct.

You need to check if you have Mvel in your application classpath. What version of Drools are you using?

Greetings.

[mschwery]

full rule

package org.drools.examples

import org.drools.WorkingMemory

import org.drools.examples.PetStore.Order

import org.drools.examples.PetStore.Purchase

import org.drools.examples.PetStore.Product

import java.util.ArrayList

import javax.swing.JOptionPane;

import javax.swing.JFrame        

global JFrame frame

global javax.swing.JTextArea textArea

//dialect "mvel"

// insert each item in the shopping cart into the Working Memory

rule "Explode Cart"

    agenda-group "init"

    auto-focus true   

    salience 10

    dialect "java"

    when

        $order : Order( grossTotal == -1 )

        $item : Purchase() from $order.items

    then

        insert( $item );

        drools.getKnowledgeRuntime().getAgenda().getAgendaGroup( "show items" ).setFocus();       

        drools.getKnowledgeRuntime().getAgenda().getAgendaGroup( "evaluate" ).setFocus();       

end

// Free Fish Food sample when we buy a Gold Fish if we haven't already  bought

// Fish Food and dont already have a Fish Food Sample

rule "Free Fish Food Sample"

    agenda-group "evaluate"

    dialect "mvel"

    when

        $order : Order()

        not ( $p : Product( name == "Fish Food") && Purchase( product == $p ))

        not ( $p : Product( name == "Fish Food Sample") && Purchase( product == $p ) )       

        exists ( $p : Product( name == "Gold Fish") && Purchase( product == $p ) )   

        $fishFoodSample : Product( name == "Fish Food Sample" );

    then

        System.out.println( "Adding free Fish Food Sample to cart" );

        purchase = new Purchase($order, $fishFoodSample);

        insert( purchase );

        $order.addItem( purchase );   

end

// Suggest a tank if we have bought more than 5 gold fish and dont already have one

rule "Suggest Tank"

       agenda-group "evaluate"

       dialect "java"

    when

        $order : Order()

        not ( $p : Product( name == "Fish Tank") && Purchase( product == $p ) )   

        ArrayList( $total : size > 5 ) from collect( Purchase( product.name == "Gold Fish" ) )

        $fishTank : Product( name == "Fish Tank" )       

    then

        requireTank(frame, drools.getWorkingMemory(), $order, $fishTank, $total);    

end   

rule "Show Items"

    agenda-group "show items"

    dialect "java"

    when

        $order : Order( )

        $p : Purchase( order == $order )

    then   

        textArea.append( $p.getProduct() + "\n");

end

rule "do checkout"

        dialect "java"

    when

    then

        doCheckout(frame, drools.getWorkingMemory());

end   

rule "Gross Total"

    agenda-group "checkout"

    dialect "mvel"

    when

        $order : Order( grossTotal == -1)

        Number( total : doubleValue ) from accumulate( Purchase( $price : product.price ),

                                                              sum( $price ) )

    then   

        modify( $order ) { grossTotal = total }

        textArea.append( "\ngross total=" + total + "\n" );

end

rule "Apply 5% Discount"

    agenda-group "checkout"

    dialect "mvel"

    when

        $order : Order( grossTotal >= 10 && < 20 )

    then

        $order.discountedTotal = $order.grossTotal * 0.95;

        textArea.append( "discountedTotal total=" + $order.discountedTotal + "\n" );       

end

rule "Apply 10% Discount"

    agenda-group "checkout"

    dialect "mvel"

    when

        $order : Order( grossTotal >= 20 )

    then

        $order.discountedTotal = $order.grossTotal * 0.90;

        textArea.append( "discountedTotal total=" + $order.discountedTotal + "\n" );   

end

function void doCheckout(JFrame frame, WorkingMemory workingMemory) {

        Object[] options = {"Yes",

                            "No"};

        int n = JOptionPane.showOptionDialog(frame,

                                             "Would you like to checkout?",

                                             "",

                                             JOptionPane.YES_NO_OPTION,

                                             JOptionPane.QUESTION_MESSAGE,

                                             null,

                                             options,

                                             options[0]);

       if (n == 0) {

            workingMemory.setFocus( "checkout" );

       }  

}

function boolean requireTank(JFrame frame, WorkingMemory workingMemory, Order order, Product fishTank, int total) {

        Object[] options = {"Yes",

                            "No"};

        int n = JOptionPane.showOptionDialog(frame,

                                             "Would you like to buy a tank for your " + total + " fish?",

                                             "Purchase Suggestion",

                                             JOptionPane.YES_NO_OPTION,

                                             JOptionPane.QUESTION_MESSAGE,

                                             null,

                                             options,

                                             options[0]);

       System.out.print( "SUGGESTION: Would you like to buy a tank for your "

                           + total + " fish? - " );

       if (n == 0) {

             Purchase purchase = new Purchase( order, fishTank );

             workingMemory.insert( purchase );

             order.addItem( purchase );

             System.out.println( "Yes" );

       } else {

            System.out.println( "No" );

       }     

       return true;

}

[mschwery]

5.1.0

[salaboy21]

Did you check if MVEL is in the classpath?

Greetings.

[mschwery]

should i see the MVEL jar under properties/java build path

[salaboy21]

can you check if you have drools-compiler in the classpath too?

Yes.. MVEL should be there..

Greetings.

[mschwery]

I see mvel in the drools runtime which is in the classpath and I've got the compiler in the classpath.

Now I'm back to the original errors