Evaluating Dynamic Formulas in Apex

Hi Friends, 

Imagine a scenario where you need to check complex conditions on an SObject record and don't want to or can't create a formula field on the object? No more complex apex code, Dynamic formula evaluation solves your problem. Let us understand it with an example.

Problems solved by dynamic formula evaluation

1. Create a formula field on the fly in the apex code.
2. Create a formula for the Wrapper class object in apex.
3. Calculate formula values at run time in apex.

Dynamic formula evaluation in Apex

Dynamic formula evaluation: an example with Standard Object

FormulaEval.FormulaInstance isPrimeCustomer = Formula.builder()
   .withType(Account.SObjectType)
   .withReturnType(FormulaEval.FormulaReturnType.BOOLEAN)
   .withFormula('AnnualRevenue > 10000 AND ISPICKVAL(Industry, "Information Technology") AND Prime_Customer__c = TRUE');

Account acc1 = new Account(
   Name = 'Test Dynamic Formula Account',
   AnnualRevenue = 20000,
   Industry = 'Information Technology',
   Prime_Customer__c = true
);

isPrimeCustomer.evaluate(acc1); // returns TRUE

Account acc2 = new Account(
   Name = 'Test Dynamic Formula Account 2',
   AnnualRevenue = 20000,
   Industry = 'Information Technology',
   Prime_Customer__c = false
);

isPrimeCustomer.evaluate(acc2); // returns FALSE


Account acc3 = new Account(
   Name = 'Test Dynamic Formula Account 3',
   AnnualRevenue = 10001,
   Industry = 'Chemical',
   Prime_Customer__c = true
);

isPrimeCustomer.evaluate(acc2); // returns FALSE

Dynamic formula evaluation: an example with Wrapper Class

global class Car {
   global Double lengthInMeters;
   global Integer numOfSeats;
   global String name;
}

Car aBoat = new Car();
aBoat.lengthInMeters = 5.2; 
aBoat.numOfSeats = 4;
aBoat.name = 'My Super car';
FormulaEval.FormulaInstance isLongCar = FormulaEval.FormulaBuilder.builder()
   .withReturnType(FormulaEval.FormulaReturnType.STRING)
   .withType(Car.class)
   .withFormula('IF(lengthInMeters > 5, "Long", "Short")')
   .build();
isLongCar.evaluate(aBoat); // Returns "Long"

What happens if the field referenced in dynamic formula evaluation is deleted?

more content coming soon.