CODEWITHSUNDEEP
c#.netdesign-patterns
dmuun
dmuun

Reputation: 1228

Need help with choosing a design pattern

Currently I have a bunch of if else statements to set CategoryId's based on how many items are in each collection.

For example,

public class TeamWork
{
    public string EmployeeName { get; set; }
    public int CategoryId { get; set; }
}

public class BLL
{
    public void SetCategoryId(ICollection<TeamWork> Converted, ICollection<TeamWork> Sourced)
    {
        if (Converted.Count == 1 && Sourced.Count == 1)
        {                
            if (String.Compare(Sourced.First().EmployeeName, Converted.First().EmployeeName) == 0)
            {
                // set category id to 1
                Converted.First().CategoryId = 1;
                Sourced.First().CategoryId = 1;                                            
            }
            else
            {
                // set category id to something                  
            }
        }
        else if (Sourced.Rows.Count == 1 && Converted.Rows.Count > 1)
        {
            // set category id to something           
        }
        // more if else statements...
    }
}

I think there's a better way to do this perhaps by applying some design pattern. Any suggestions? Thanks!

Upvotes: 3

Views: 284

Answers (2)

KeithS
KeithS

Reputation: 71591

A Strategy pattern comes to mind. Try to break these rules down into a series of "if this condition is true, then the category ID is this". Make each one of these a method, then add those methods as delegates to a List<Func<ICollection<TeamWork>, ICollection<TeamWork>, bool>> or a comparable indexed collection. Then, your SetCategoryId() code looks like this:

public void SetCategoryId(ICollection<TeamWork> Converted, ICollection<TeamWork> Sourced)
{
    foreach(var categoryRule in CategoryRules)
    {
       var category = test(Converted, Sourced);
       if(category != 0)
       {
          Converted.First().CategoryId = Sourced.First().CategoryId = category;
          break;
       }
    }
}

The above code would never have to change regardless of how many rules you added or removed. However, with the if - else if structure you have, your series of rules will likely be order-dependent, so be careful when setting up the rules in the list.

Upvotes: 1

Aliostad
Aliostad

Reputation: 81700

Chain of responsibility is the way to go.

So this object is passed to a series of command objects until one is able to act upon and set the status.

Upvotes: 4

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