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@DavidSSL
Created May 1, 2013
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using System;
using System.Collections;
using System.Collections.Generic;
using System.Linq;
using System.Reflection;
namespace WickedDomainModels.Model
{
[Serializable]
public abstract class Enumeration : IComparable
{
private readonly int _value;
private readonly string _displayName;
protected Enumeration()
{
}
protected Enumeration(int value, string displayName)
{
_value = value;
_displayName = displayName;
}
public int Value
{
get { return _value; }
}
public string DisplayName
{
get { return _displayName; }
}
public override string ToString()
{
return DisplayName;
}
public static IEnumerable<T> GetAll<T>() where T : Enumeration
{
var type = typeof(T);
var fields = type.GetFields(BindingFlags.Public | BindingFlags.Static | BindingFlags.DeclaredOnly);
return fields.Select(info => info.GetValue(null)).OfType<T>();
}
public static IEnumerable GetAll(Type type)
{
var fields = type.GetFields(BindingFlags.Public | BindingFlags.Static | BindingFlags.DeclaredOnly);
return fields.Select(info => info.GetValue(null));
}
public override bool Equals(object obj)
{
var otherValue = obj as Enumeration;
if (otherValue == null)
{
return false;
}
var typeMatches = GetType().Equals(obj.GetType());
var valueMatches = _value.Equals(otherValue.Value);
return typeMatches && valueMatches;
}
public override int GetHashCode()
{
return _value.GetHashCode();
}
public static int AbsoluteDifference(Enumeration firstValue, Enumeration secondValue)
{
var absoluteDifference = Math.Abs(firstValue.Value - secondValue.Value);
return absoluteDifference;
}
public static T FromValue<T>(int value) where T : Enumeration
{
var matchingItem = parse<T, int>(value, "value", item => item.Value == value);
return matchingItem;
}
public static T FromDisplayName<T>(string displayName) where T : Enumeration
{
var matchingItem = parse<T, string>(displayName, "display name", item => item.DisplayName == displayName);
return matchingItem;
}
private static T parse<T, K>(K value, string description, Func<T, bool> predicate) where T : Enumeration
{
var matchingItem = GetAll<T>().FirstOrDefault(predicate);
if (matchingItem == null)
{
var message = string.Format("'{0}' is not a valid {1} in {2}", value, description, typeof(T));
throw new ApplicationException(message);
}
return matchingItem;
}
public virtual int CompareTo(object other)
{
return Value.CompareTo(((Enumeration)other).Value);
}
}
}
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