ASP.NET MVC 3 List<T> to IEnumerable<SelectListItem> - asp.net-mvc

Question

I'm not currently happy with the way that my DropDownListFor() objects are populated. I'm attempting to find as generic way of populating IEnumerable as possible. This is what I have so far.
Helper:
public static List<SelectListItem> ToSelectList(IDictionary<string,string> dictionaryItems, string selectedValue, string noSelection, bool search = false)
{
List<SelectListItem> items = new List<SelectListItem>();
if (search)
{
items.Add(new SelectListItem { Selected = true, Value = "-1", Text = string.Format("-- {0} --", noSelection) });
}
foreach (var item in dictionaryItems)
{
items.Add(new SelectListItem
{
Text = item.Key,
Value = item.Value,
Selected = selectedValue == item.Value ? true : false
});
}
return items
.OrderBy(l => l.Text)
.ToList();
}
Controller:
[HttpGet]
public ActionResult Index()
{
var model = new CreateModel();
var parentOrganisations = _orgs.FindBy(o => o.OwningOrganisationID == Globals.OrganisationID || o.ID == Globals.OrganisationID)
.OrderBy(o => o.OrganisationName);
Dictionary<string, string> items = new Dictionary<string, string>();
foreach (var item in parentOrganisations)
{
items.Add(item.OrganisationName, item.ID.ToString());
}
model.Organisations = SelectLists.ToSelectList(items, "-1", "-- None -- ", true);
return View(model);
}
View:
<div class="control-group">
<label class="control-label">Parent Organisation</label>
<div class="controls">
#Html.DropDownListFor(m => m.ParentOrganisationID, Model.Organisations, new { #class = "input-xlarge"})
<p class="help-block">Select a parent organisation to create a branch</p>
</div>
</div>
There seems to be A LOT of repetitive code in the controller. It takes a generic list, add's the Value and Text to a Dictionary and then uses that as input for a helper which builds up the select list to send as part of the model.
Does anyone have any better ways to achieve this? I hate having bloat in my controller, and when I get several drop downs on a form this is exactly what will happen in this instance.
Thanks,
EDIT - Thanks to Kenneth's helper method, I've now consolidated the whole thing into one call in the controller:
model.Organisations = _orgs.FindBy(o => o.OwningOrganisationID == Globals.OrganisationID || o.ID == Globals.OrganisationID)
.OrderBy(o => o.OrganisationName)
.ToList()
.ToSelectList(org => org.OrganisationName, org => org.ID.ToString(), "-1", "None", true);

Answer 1

You could provide callbacks that obtain the key and the value and then use those. Apart from that you can create it as an extension method:
Extension method:
public static List<SelectListItem> ToSelectList<T>(this List<T> Items, Func<T, string> getKey, Func<T, string> getValue, string selectedValue, string noSelection, bool search = false)
{
List<SelectListItem> items = new List<SelectListItem>();
if (search)
{
items.Add(new SelectListItem { Selected = true, Value = "-1", Text = string.Format("-- {0} --", noSelection) });
}
foreach (var item in Items)
{
items.Add(new SelectListItem
{
Text = getKey(item),
Value = getValue(item),
Selected = selectedValue == getValue(item) ? true : false
});
}
return items
.OrderBy(l => l.Text)
.ToList();
}
Usage:
List<Org>() parentOrganisations = // fetch here
model.Organisations = parentOrganisations.ToSelectList(org => org.ID.ToString(),
org => org.OrganisationName,
"-1",
"-- None -- ",
true);
Note: I typed this in the SO-editor, so you might have some syntax errors (they should be easy to solve though).

Answer 2

You can do in controller only like this: -
List<SelectListItem> dropdownItems = parentOrganisations
.Select(item => new SelectListItem
{
Value = item.ID.ToString(),
Text = item.OrganisationName,
Selected = "-1" == item.ID.ToString() ? true : false
})
.ToList();