Question
How can i evaluate a boolean expression and get its value?
How can i evaluate an expression and get its returned value to a clipboard page?
i have an expression in a property value as ((true AND false) OR (True AND True)). now i want to evaluate it and get the returned boolean result to pega clipboard page?
do we have any similar method/ function in java/pega which is similar to eval() function in JSP?
please suggest on how can i achieve this.
***Updated by moderator: Lochan to add Category
Thanks,
karun
Pegasystems Inc.
GB
Hi Karun,
One possible way of doing this - would be to use to build a Decision Table that has your properties and logic in it.
In an Activity you could then use the Method "Property-Map-DecisionTable" to set another Property to the resultant calculation.
Cheers
John
Virtusa Consulting Services Pvt. Ltd
US
Hi John,
Thanks for your response, but we dont have a predefined number of properties or predefined logic to be executed.
we will evaluate some business rules and build this expression dynamically and store it in a string property .
for ex:- we have a criteria to validate a set of business rules BR1, BR2, BR3 BR4. user will select the business criteria from front end as ((BR1 and BR2) OR (BR1 and BR3)) OR BR4 ( Note:- User can change this criteria from front end. ) so we will evaluate this business rules and build the resultant criteria like ., (((true and true) OR (true and false) ) OR false) . now, we need to evalute the final boolean outcome of this.
please Suggest.
Thanks,
karun
Pegasystems Inc.
US
Hello Karun,
So if I understand, you have a list of n boolean values and you basically want to determine if any of them are false, if so return false, otherwise return true? I don't know of a single method that when called would do that for you, especially while parcing a string, but you can definitely write something. If you have a true page/value list, you can use an interator to walk through it and determine if any one value is false. I'm thinking if you initialize the value to whichever you would rather return (i.e. if the list is of length 0, so you never evaluate any, would you rather return true or false?), you could build this in a couple of activity steps.
If you really need the complex logic (I'm not sure I understand how you are building that without knowing ahead of time, but okay?), then you might need to drop into Java and build something that does a lot more complex string maniupulation. Assuming there aren't any available libraries that do the work for you that you might want to make use of.
Thanks,
Mike