How to retrieve list of Non Selected Items from MultiListField?

Question

I'm trying to get a list of all available/non selected items in from a MultilistField.

I know you can use this to get the selected items

applicationField.GetItems()

How do I go about getting the list of available items to use?

Thanks!

Answer 1

Something like this should do the trick:

// get the "Source" string from the template field
var sourceString = applicationField.InnerField.Source;

// get the item from which the field comes from
var currentItem = applicationField.InnerField.Item;

// get selected ids of selected items
var selectedItems = applicationField.TargetIDs;

using (new LanguageSwitcher(currentItem.Language))
{
    // get all the items based on the "Source" string and item
    var allItems = LookupSources.GetItems(currentItem, sourceString);

    // filter out selected from all the items 
    var unselectedItems = allItems.Where(item => !selectedItems.Contains(item.ID));
}