Enum and Dictionary<Enum, Action>

Question

I hope I can explain my problem in a way that it's clear for everyone. We need your suggestions on this.

We have an Enum Type which has more than 15 constants defined. We receive a report from a web service and translate its one column into this Enum type. And based on what we receive from that web service, we run specific functions using Dictionary

Why am I asking for ideas? Let's say 3 of these Enum contants meet specific functions in our Dictionary but the rest use the same function. So, is there a way to add them into our Dictionary in a better way rather than adding them one by one? I also want to keep this structure because when it's time, we might have specific functions in the future for the ones that I described as "the rest".

To be more clear here's an example what we're trying to do:

Enum:

public enum Reason{
    ReasonA,
    ReasonB,
    ReasonC,
    ReasonD,
    ReasonE,
    ReasonF,
    ReasonG,
    ReasonH,
    ReasonI,
    ReasonJ,
    ReasonK
}

Defining our Dictionary:

public Dictionary<Reason, Action<CustomClassObj, string>> ReasonHandlers = new Dictionary<Reason, Action<CustomClassObj, string>>{
    { Reason.ReasonA, HandleReasonA },
    { Reason.ReasonB, HandleReasonB },
    { Reason.ReasonC, HandleReasonC },
    { Reason.ReasonD, HandleReasonGeneral },
    { Reason.ReasonE, HandleReasonGeneral },
    { Reason.ReasonF, HandleReasonGeneral },
    { Reason.ReasonG, HandleReasonGeneral },
    { Reason.ReasonH, HandleReasonGeneral },
    { Reason.ReasonI, HandleReasonGeneral },
    { Reason.ReasonJ, HandleReasonGeneral },
    { Reason.ReasonK, HandleReasonGeneral }
};

So basically what I'm asking is, is there a way to add Reason, Function pair more intelligently? Because as you can see after ReasonC, all other reasons use the same function.

Thank you for your suggestions.

Answer 1

You could try something like this, only put the custom Reason handler in the dictionary and then fallback to the General one.

public Dictionary<Reason, Action<CustomClassObj, string>> ReasonHandlers = new Dictionary<Reason, Action<CustomClassObj, string>>{
    { Reason.ReasonA, HandleReasonA },
    { Reason.ReasonB, HandleReasonB },
    { Reason.ReasonC, HandleReasonC }};


public Action<CustomClassObj, string> ReasonHandlerLookup (Reason reason) {
    Action<CustomClassObj, string> result = null;
    ReasonHandlers.TryGetValue(reason, out result);
    return result ?? HandleReasonGeneral;
}