Question

I have a few web sites and load articles on the main page. I can set ranking on the articles to display them in different order but the ordering could be different on the various sites for the articles.

The code I have to order the articles sets the same order for all sites:

    string officeLocation = "";
    // office location could be either World, Europe, Africa, America, Asia, Pacific

    var result = articles.Select(a => new
    {
        Title = a.Title,
        Url = a[SPBuiltInFieldId.FileRef],
        Byline = a[Constants.FieldNames.Byline],
        ArticleDate = a[Constants.FieldNames.ArticleStartDate],
        RankWorld = a[Constants.FieldNames.World],
        RankEurope = a[Constants.FieldNames.RankEurope],
        RankAfrica = a[Constants.FieldNames.RankAfrica],
        RankAmerica = a[Constants.FieldNames.RankAmerica],
        RankAsia = a[Constants.FieldNames.RankAsia],
        RankPacific = a[Constants.FieldNames.RankPacific],
    });

    rptArticles.DataSource = result.OrderBy(a => a.RankWorld);
    rptArticles.DataBind();

The code sets all ranking to whatever RankWorld is (1-6).

If the string officeLocation (that is passed on to the method) is Europe then I want to order by a.RankEurope, if officeLocation is Asia order by a.RankAsia and so on.

How can I best achieve this (.NET 3.5)?

Thanks in advance.

Answer 1

Assuming you have a fixed set of locations (which by definition, you must have as you’re stating them in the anonymous type) then you could just use a switch:

string officeLocation = "";
// office location could be either World, Europe, Africa, America, Asia, Pacific

var result = articles.Select(a => new
{
    Title = a.Title,
    Url = a[SPBuiltInFieldId.FileRef],
    Byline = a[Constants.FieldNames.Byline],
    ArticleDate = a[Constants.FieldNames.ArticleStartDate],
    RankWorld = a[Constants.FieldNames.World],
    RankEurope = a[Constants.FieldNames.RankEurope],
    RankAfrica = a[Constants.FieldNames.RankAfrica],
    RankAmerica = a[Constants.FieldNames.RankAmerica],
    RankAsia = a[Constants.FieldNames.RankAsia],
    RankPacific = a[Constants.FieldNames.RankPacific],
});

switch (officeLocation)
{
    case "World": result = result.OrderBy(a => a.RankWorld); break;
    case "Europe": result = result.OrderBy(a => a.RankEurope); break;
    case "Africa": result = result.OrderBy(a => a.RankAfrica); break;
    case "America": result = result.OrderBy(a => a.RankAmerica); break;
    case "Asia": result = result.OrderBy(a => a.RankAsia); break;
    case "Pacific": result = result.OrderBy(a => a.RankPacific); break;
    default: throw new Exception("Unexpected location: " + officeLocation);
}

rptArticles.DataSource = result.OrderBy(a => a.RankWorld);
rptArticles.DataBind();

Obviously, you need to decide how best to handle an unexpected location.

Note that, ideally, I would have just assigned the OrderBy function to a Func<T,R>, but and only have one OrderBy call, but you can’t do that here due to the anonymous type.