You are doing validation in Apex wrong!
Chain of Responsibility is a behavioral design pattern that lets you pass requests along a chain of handlers. Upon receiving a request, each handler decides either to process the request…
Use Chain of Responsibility design pattern, but what is that?
Chain of Responsibility is a behavioral design pattern that lets you pass requests along a chain of handlers. Upon receiving a request, each handler decides either to process the request or to pass it to the next handler in the chain.
First create Validator abstract class:
public abstract class Validator {
protected Validator next;
public virtual Validator setNext(List<String> validations) {
if (!validations.isEmpty()) {
next = (Validator) Type.forName(validations.remove(0)).newInstance();
next.setNext(validations);
}
return this;
}
public abstract Boolean isValid(Account record);
}And then extend it with your custom isValid, validation method:
public class AccountIndustryValidator extends Validator {
private static final List<String> SUPPORTED_INDUSTRIES = new List<String>{
'Electronics', 'Engineering'
};
public override Boolean isValid(Account account) {
return SUPPORTED_INDUSTRIES.contains(account?.Industry) &&
(next == null ? true : next.isValid(account));
}
}Finally, we can use new Validators, to check if the Account we got is a valid one:
public with sharing class AccountController {
public static Account createAccount(Account account) {
Validator validator = new AccountIndustryValidator()
.setNext(new List<String>{ 'AccountTypeValidator' });
if (validator.isValid(account)) {
insert account;
}
return account;
}
}We create the first Validator manually, then all the logic is handled recursively thanks to implementation in an abstract class. In this implementation we are leveraging Dynamic Apex, it gives a lot of flexibility, you can change implementation to use, for example, Custom Metadata!
