/// <summary>
/// Verify that the current Key Type is set to a specific value, or throw an Exception.
/// </summary>
/// <param name="keyType"></param>
private void VerifyRequiredKeyTypeOrThrow(SingleEntityPickerKeySpecifier keyType)
{
if (keyType == SingleEntityPickerKeySpecifier.Guid &&
_Key != SingleEntityPickerKeySpecifier.Guid)
{
throw new Exception("Invalid Operation. This operation is only available when KeyType is set to \"Guid\".");
}
else if (keyType == SingleEntityPickerKeySpecifier.Id &&
_Key != SingleEntityPickerKeySpecifier.Id)
{
throw new Exception("Invalid Operation. This operation is only available when KeyType is set to \"Id\".");
}
}
/// <summary>
/// Initializes the list of available items.
/// </summary>
/// <param name="entities"></param>
/// <param name="itemDescriptionExpression"></param>
/// <param name="keyType"></param>
/// <param name="allowEmptySelection"></param>
public void InitializeListItems(IEnumerable <TEntity> entities, Expression <Func <TEntity, string> > itemDescriptionExpression, SingleEntityPickerKeySpecifier keyType = SingleEntityPickerKeySpecifier.Id, bool allowEmptySelection = false)
{
var mexpr = itemDescriptionExpression.Body as MemberExpression;
if (mexpr == null)
{
return;
}
var func = itemDescriptionExpression.Compile();
this.Items.Clear();
_Key = keyType;
if (allowEmptySelection)
{
this.Items.Add(new ListItem());
}
foreach (var entity in entities)
{
var description = func(entity);
string key;
if (_Key == SingleEntityPickerKeySpecifier.Guid)
{
key = entity.Guid.ToString();
}
else
{
key = entity.Id.ToString();
}
this.Items.Add(new ListItem(description, key));
}
}
