Use properties or methods to expose business rules in C#?
- by Val
I'm writing a class to encapsulate some business rules, each of which is represented by a boolean value. The class will be used in processing an InfoPath form, so the rules get the current program state by looking up values in a global XML data structure using XPath operations. What's the best (most idiomatic) way to expose these rules to callers -- properties or public methods?
Call using properties
Rules rules = new Rules();
if ( rules.ProjectRequiresApproval ) {
// get approval
} else {
// skip approval
}
Call using methods
Rules rules = new Rules();
if ( rules.ProjectRequiresApproval() ) {
// get approval
} else {
// skip approval
}
Rules class exposing rules as properties
public class Rules() {
private int _amount;
private int threshold = 100;
public Rules() {
_amount = someExpensiveXpathOperation;
}
// rule property
public bool ProjectRequiresApproval {
get { return _amount < threshold }
}
}
Rules class exposing rules as methods
public class Rules() {
private int _amount;
private int threshold = 100;
public Rules() {
_amount = someExpensiveXpathOperation;
}
// rule method
public bool ProjectRequiresApproval() {
return _amount < threshold;
}
}
What are the pros and cons of one over the other?
