IEnumableExtension

IEnumableExtension

///Summary
///IEnumableExtension is another common used in c# MVC. In the dropdown List
///Summary
  public static class IEnumerableExtensions
    {
        public static string JoinString(this IEnumerable<string> values)
        {
            return JoinString(values, ",");
        }

        public static string JoinString(this IEnumerable<string> values, string split)
        {
            var result = values.Aggregate(string.Empty, (current, value) => current + (split + value));
            result = result.TrimStart(split.ToCharArray());
            return result;
        }

        public static IEnumerable<T> Each<T>(this IEnumerable<T> source, Action<T> action)
        {
            if (source != null)
            {
                foreach (var item in source)
                {
                    action(item);
                }
            }
            return source;
        }


        public static IList<SelectListItem> ToSelectList<T>(this IEnumerable<T> source, Func<T, object> text, Func<T, object> value)
        {
            return source.ToSelectList(text, value, null, null);
        }

        public static IList<SelectListItem> ToSelectList<T>(this IEnumerable<T> source, Func<T, object> text, Func<T, object> value, string optionalText)
        {
            return source.ToSelectList(text, value, null, optionalText);
        }

        public static IList<SelectListItem> ToSelectList<T>(this IEnumerable<T> source, Func<T, object> text, Func<T, object> value, Func<T, bool> selected)
        {
            return source.ToSelectList(text, value, selected, null);
        }

        public static IList<SelectListItem> ToSelectList<T>(this IEnumerable<T> source, Func<T, object> text, Func<T, object> value, Func<T, bool> selected, string optionalText)
        {
            return source.ToSelectList(text, value, selected, optionalText, string.Empty);
        }

        public static IList<SelectListItem> ToSelectList<T>(this IEnumerable<T> source, Func<T, object> text, Func<T, object> value, Func<T, bool> selected, string optionalText, string optionalValue)
        {
            var items = new List<SelectListItem>();
            if (source == null)
            {
                return items;
            }
            foreach (var entity in source)
            {
                var item = new SelectListItem();
                item.Text = text(entity).ToString();
                item.Value = value(entity).ToString();
                if (selected != null)
                {
                    item.Selected = selected(entity);
                }

                switch (item.Text.ToLower())
                {
                    case "other":
                    case "others":
                        item.Text = " " + item.Text;
                        break;
                }

                if (item.Value != optionalValue)
                {
                    items.Add(item);
                }
            }
            items = items.OrderBy(d => d.Text).ToList();
            var otherItem = items.Where(d => d.Text.ToLower().StartsWith(" other"));
            otherItem.Each(d =>
            {
                d.Text = d.Text.Replace(" ", "");
            });

            if (!string.IsNullOrEmpty(optionalText))
            {
                items.Insert(0, new SelectListItem() { Text = optionalText, Value = optionalValue });
            }
            return items;
        }

    }