I have a function that is using UmbracoHelper - it is in a class library and it's going to be used in foreach loops about 50% of the time.

A simplified version is as follows:

public static IEnumerable<IPublishedContent> GetPickerItems(this IPublishedContent item, string pickerAlias)
{
    Umbraco.Web.UmbracoHelper u = new Umbraco.Web.UmbracoHelper(UmbracoContext.Current);

    if (!item.HasValue(pickerAlias)) { yield break; }

    foreach (string pageId in item.GetPropertyValue<string>(pickerAlias, "").Split(','))
    {
        yield return u.TypedContent(pageId);
    }
}

I am wondering about the following:

1. Is it right to use UmbracoHelper this way? The function works, but is there something I'm missing regarding the scope of UmbracoContext.Current?

2. Should I instantiate a new UmbracoHelper in every call (as I'm doing right now) or pass one as a parameter? I examined the code for UmbracoHelper and saw that it's a lightweight object - most calls do lazy instantiation, so I don't think it's going to have a big performance/memory hit as it is now, but again, is there something I'm missing?