Adding Convenience Methods to Classes

Code can often be simplified by adding a few convenience methods to our classes. For instance, one set of classes were littered with code like this:

CommandInitDataEntity data = CommandEntity.InitDatas.SingleOrDefault (x => x.Key == InitDataKeys.MoiBliscyUpgradeType.ToString ());
if (data != null)
{
    this.UpgradeType = (UpgradeType) Enum.Parse (typeof (UpgradeType), data.Value);
}

I added the following convenience methods to the CommandEntity class:

public bool HasInitData (
    string key)
{
    return this.InitDatas.ToList ().Exists (x => x.Key == key);
}

public bool HasInitData (
    Enum key)
{
    return HasInitData (key.ToString ());
}

public string GetValueFromInitData (
    string key)
{
    return this.InitDatas.Single (x => x.Key == key).Value;
}

public string GetValueFromInitData (
    Enum key)
{
    return GetValueFromInitData (key.ToString ());
}

public T GetValueFromInitData (
    Enum key)
    where T : struct, IConvertible
{
    Type type = typeof (T);
    if (type.IsEnum)

    {
        return (T) Enum.Parse (typeof (T), GetValueFromInitData (key));
    }

    throw new NotImplementedException ("Unsupported type");
 }

I could then rewrite the original code like this:

if (commandEntity.HasInitData (InitDataKeys.MoiBliscyUpgradeType))
{
    this.UpgradeType = commandEntity.GetValueFromInitData (InitDataKeys.MoiBliscyUpgradeType);
}
 

It may not seem like a big difference, but well designed software is achieved though hundreds of little decisions that all add up.